"Knowledge is powerful, be careful how you use it!"

A collection of inspiring lists, manuals, cheatsheets, blogs, hacks, one-liners, cli/web tools and more.

_{Created by trimstray and contributors}

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📔  What is it?

This list is a collection of various materials and tools that I use every day in my work. It contains a lot of useful information gathered in one piece.

🚻  For whom?

This collection is suitable for everyone. It is aimed towards System and Network administrators, DevOps, Pentesters and Security Researchers.

ℹ�  Contributing

If you find something which doesn't make sense, or something doesn't seem right, please make a pull request and please add valid and well-reasoned explanations about your changes or comments.

A few simple rules for this project:

• inviting and clear
• not tiring
• useful

These below rules may be better:

• easy to contribute to (Markdown + HTML ...)
• easy to find (simple TOC, maybe it's worth extending them?)

Url marked * is temporary unavailable. Please don't delete it without confirming that it has permanently expired.

Before adding a pull request, please see the contributing guidelines. All suggestions/PR are welcome!

�  Support

If this project is useful and important for you or if you really like the-book-of-secret-knowledge, you can bring positive energy by giving some good words or supporting this project. Thank you!

☑�  Todo

• Add useful shell functions
• Add one-liners for collection tools (eg. CLI Tools)

💢  Table of Contents

Only main chapters:

• CLI Tools
• GUI Tools
• Web Tools
• Systems/Services
• Networks
• Manuals/Howtos/Tutorials
• Inspiring Lists
• Blogs/Podcasts/Videos
• Hacking/Penetration Testing
• Your daily knowledge and news
• Other Cheat Sheets
• One-liners
• Shell functions

🔱  The Book of Secret Knowledge (Chapters)

CLI Tools  ^[TOC]

▪� Shells

  🔸 GNU Bash - is an sh-compatible shell that incorporates useful features from the Korn shell and C shell.
  🔸 Zsh - is a shell designed for interactive use, although it is also a powerful scripting language.
  🔸 bash-it - is a framework for using, developing and maintaining shell scripts and custom commands.
  🔸 Oh My ZSH! - is the best framework for managing your Zsh configuration.
  🔸 Oh My Fish - the Fishshell framework.

▪� Managers

  🔸 Midnight Commander - is a visual file manager, licensed under GNU General Public License.
  🔸 ranger - is a VIM-inspired filemanager for the console.
  🔸 nnn - is a tiny, lightning fast, feature-packed file manager.
  🔸 screen - is a full-screen window manager that multiplexes a physical terminal.
  🔸 tmux - is a terminal multiplexer, lets you switch easily between several programs in one terminal.
  🔸 tmux-cssh - is a tool to set comfortable and easy to use functionality, clustering and synchronizing tmux-sessions.

▪� Text editors

  🔸 vi - is one of the most common text editors on Unix.
  🔸 vim - is a highly configurable text editor.
  🔸 emacs - is an extensible, customizable, free/libre text editor - and more.

▪� Files and directories

  🔸 fd - is a simple, fast and user-friendly alternative to find.

▪� Network

  🔸 PuTTY - is an SSH and telnet client, developed originally by Simon Tatham.
  🔸 nmap - is a free and open source (license) utility for network discovery and security auditing.
  🔸 masscan - is the fastest Internet port scanner, spews SYN packets asynchronously.
  🔸 pbscan - is a faster and more efficient stateless SYN scanner and banner grabber.
  🔸 hping - is a command-line oriented TCP/IP packet assembler/analyzer.
  🔸 mtr - is a tool that combines the functionality of the 'traceroute' and 'ping' programs in a single network diagnostic tool.
  🔸 netcat - is a networking utility which reads and writes data across network connections, using the TCP/IP protocol.
  🔸 tcpdump - is a powerful command-line packet analyzer.
  🔸 tshark - is a tool that allows us to dump and analyze network traffic (wireshark cli).
  🔸 Termshark - is a simple terminal user-interface for tshark.
  🔸 ngrep - is like GNU grep applied to the network layer.
  🔸 sockdump - dump unix domain socket traffic.
  🔸 stenographer - is a packet capture solution which aims to quickly spool all packets to disk.
  🔸 bmon - is a monitoring and debugging tool to capture networking related statistics and prepare them visually.
  🔸 iptraf-ng - is a console-based network monitoring program for Linux that displays information about IP traffic.
  🔸 iPerf3 - is a tool for active measurements of the maximum achievable bandwidth on IP networks.
  🔸 ethr - is a Network Performance Measurement Tool for TCP, UDP & HTTP.
  🔸 Etherate - is a Linux CLI based Ethernet and MPLS traffic testing tool.
  🔸 echoip - is a IP address lookup service.
  🔸 Nemesis - packet manipulation CLI tool; craft and inject packets of several protocols.
  🔸 packetfu - a mid-level packet manipulation library for Ruby.
  🔸 Scapy - packet manipulation library; forge, send, decode, capture packets of a wide number of protocols.
  🔸 impacket - is a collection of Python classes for working with network protocols.
  🔸 ssh-audit - is a tool for SSH server auditing.
  🔸 aria2 - is a lightweight multi-protocol & multi-source command-line download utility.
  🔸 iptables-tracer - observe the path of packets through the iptables chains.

▪� Network (DNS)

  🔸 fierce - is a DNS reconnaissance tool for locating non-contiguous IP space.
  🔸 subfinder - is a subdomain discovery tool that discovers valid subdomains for websites.
  🔸 sublist3r - is a fast subdomains enumeration tool for penetration testers.
  🔸 amass - is tool that obtains subdomain names by scraping data sources, crawling web archives and more.
  🔸 namebench - provides personalized DNS server recommendations based on your browsing history.
  🔸 knock - is a tool to enumerate subdomains on a target domain through a wordlist.
  🔸 dnscrypt-proxy 2 - a flexible DNS proxy, with support for encrypted DNS protocols.
  🔸 dnsdbq - API client providing access to passive DNS database systems (pDNS at Farsight Security, CIRCL pDNS).

▪� Network (HTTP)

  🔸 Curl - is a command line tool and library for transferring data with URLs.
  🔸 kurly - is an alternative to the widely popular curl program, written in Golang.
  🔸 HTTPie - is an user-friendly HTTP client.
  🔸 wuzz - is an interactive cli tool for HTTP inspection.
  🔸 htrace.sh - is a simple Swiss Army knife for http/https troubleshooting and profiling.
  🔸 httpstat - is a tool that visualizes curl statistics in a way of beauty and clarity.
  🔸 httplab - is an interactive web server.
  🔸 Lynx - is a text browser for the World Wide Web.
  🔸 HeadlessBrowsers - a list of (almost) all headless web browsers in existence.
  🔸 ab - is a single-threaded command line tool for measuring the performance of HTTP web servers.
  🔸 siege - is an http load testing and benchmarking utility.
  🔸 wrk - is a modern HTTP benchmarking tool capable of generating significant load.
  🔸 wrk2 - is a constant throughput, correct latency recording variant of wrk.
  🔸 bombardier - is a fast cross-platform HTTP benchmarking tool written in Go.
  🔸 gobench - http/https load testing and benchmarking tool.
  🔸 hey - HTTP load generator, ApacheBench (ab) replacement, formerly known as rakyll/boom.
  🔸 boom - is a script you can use to quickly smoke-test your web app deployment.
  🔸 SlowHTTPTest - is a tool that simulates some Application Layer Denial of Service attacks by prolonging HTTP.
  🔸 gobuster - is a free and open source directory/file & DNS busting tool written in Go.

▪� SSL

  🔸 openssl - is a robust, commercial-grade, and full-featured toolkit for the TLS and SSL protocols.
  🔸 gnutls-cli - client program to set up a TLS connection to some other computer.
  🔸 sslyze - fast and powerful SSL/TLS server scanning library.
  🔸 sslscan - tests SSL/TLS enabled services to discover supported cipher suites.
  🔸 testssl.sh - testing TLS/SSL encryption anywhere on any port.
  🔸 cipherscan - a very simple way to find out which SSL ciphersuites are supported by a target.
  🔸 spiped - is a utility for creating symmetrically encrypted and authenticated pipes between socket addresses.
  🔸 Certbot - is EFF's tool to obtain certs from Let's Encrypt and (optionally) auto-enable HTTPS on your server.
  🔸 mkcert - simple zero-config tool to make locally trusted development certificates with any names you'd like.
  🔸 Sublert - is a security and reconnaissance tool to automatically monitor new subdomains.
  🔸 mkchain - open source tool to help you build a valid SSL certificate chain.

▪� Security

  🔸 SELinux - provides a flexible Mandatory Access Control (MAC) system built into the Linux kernel.
  🔸 AppArmor - proactively protects the operating system and applications from external or internal threats.
  🔸 grapheneX - Automated System Hardening Framework.
  🔸 DevSec Hardening Framework - Security + DevOps: Automatic Server Hardening.

▪� Auditing Tools

  🔸 ossec - actively monitoring all aspects of system activity with file integrity monitoring.
  🔸 auditd - provides a way to track security-relevant information on your system.
  🔸 Tiger - is a security tool that can be use both as a security audit and intrusion detection system.
  🔸 Lynis - battle-tested security tool for systems running Linux, macOS, or Unix-based operating system.
  🔸 LinEnum - scripted Local Linux Enumeration & Privilege Escalation Checks.
  🔸 Rkhunter - scanner tool for Linux systems that scans backdoors, rootkits and local exploits on your systems.
  🔸 PE-sieve - is a light-weight tool that helps to detect malware running on the system.

▪� System Diagnostics/Debuggers

  🔸 strace - diagnostic, debugging and instructional userspace utility for Linux.
  🔸 DTrace - is a performance analysis and troubleshooting tool.
  🔸 ltrace - is a library call tracer, used to trace calls made by programs to library functions.
  🔸 perf-tools - performance analysis tools based on Linux perf_events (aka perf) and ftrace.
  🔸 bpftrace - high-level tracing language for Linux eBPF.
  🔸 sysdig - system exploration and troubleshooting tool with first class support for containers.
  🔸 Valgrind - is an instrumentation framework for building dynamic analysis tools.
  🔸 gperftools - high-performance multi-threaded malloc() implementation, plus some performance analysis tools.
  🔸 glances - cross-platform system monitoring tool written in Python.
  🔸 htop - interactive text-mode process viewer for Unix systems. It aims to be a better 'top'.
  🔸 atop - ASCII performance monitor. Includes statistics for CPU, memory, disk, swap, network, and processes.
  🔸 lsof - displays in its output information about files that are opened by processes.
  🔸 FlameGraph - stack trace visualizer.
  🔸 lsofgraph - small utility to convert Unix lsof output to a graph showing FIFO and UNIX interprocess communication.
  🔸 rr - is a lightweight tool for recording, replaying and debugging execution of applications.
  🔸 Performance Co-Pilot - a system performance analysis toolkit.
  🔸 hexyl - a command-line hex viewer.

▪� Log Analyzers

  🔸 angle-grinder - slice and dice log files on the command line.
  🔸 lnav - log file navigator with search and automatic refresh.
  🔸 GoAccess - real-time web log analyzer and interactive viewer that runs in a terminal.
  🔸 ngxtop - real-time metrics for nginx server.

▪� Databases

  🔸 usql - universal command-line interface for SQL databases.
  🔸 pgcli - postgres CLI with autocompletion and syntax highlighting.
  🔸 mycli - terminal client for MySQL with autocompletion and syntax highlighting.

▪� TOR

  🔸 Nipe - script to make Tor Network your default gateway.
  🔸 multitor - a tool that lets you create multiple TOR instances with a load-balancing.

▪� Other

  🔸 incron - is an inode-based filesystem notification technology.
  🔸 GRV - is a terminal based interface for viewing Git repositories.
  🔸 Tig - text-mode interface for Git.
  🔸 tldr - simplified and community-driven man pages.
  🔸 archiver - easily create and extract .zip, .tar, .tar.gz, .tar.bz2, .tar.xz, .tar.lz4, .tar.sz, and .rar.
  🔸 commander.js - minimal CLI creator in JavaScript.
  🔸 gron - make JSON greppable!

GUI Tools  ^[TOC]

▪� Terminal emulators

  🔸 Guake - is a dropdown terminal made for the GNOME desktop environment.
  🔸 Terminator - is based on GNOME Terminal, useful features for sysadmins and other users.
  🔸 Kitty - is a GPU based terminal emulator that supports smooth scrolling and images.

▪� Network

  🔸 Wireshark - is the world’s foremost and widely-used network protocol analyzer.
  🔸 Ettercap - is a comprehensive network monitor tool.
  🔸 EtherApe - is a graphical network monitoring solution.
  🔸 JMeter™ - open source software to load test functional behavior and measure performance.
  🔸 locust - scalable user load testing tool written in Python.

▪� Browsers

  🔸 TOR Browser - protect your privacy and defend yourself against network surveillance and traffic analysis.

▪� Password Managers

  🔸 KeePassXC - store your passwords safely and auto-type them into your everyday websites and apps.
  🔸 Enpass - password manager and secure wallet.

▪� Messengers/IRC Clients

  🔸 HexChat - is an IRC client based on XChat.
  🔸 Pidgin - is an easy to use and free chat client used by millions.

▪� Messengers (end-to-end encryption)

  🔸 Signal - is an encrypted communications app.
  🔸 Wire - secure messaging, file sharing, voice calls and video conferences. All protected with end-to-end encryption.
  🔸 TorChat - decentralized anonymous instant messenger on top of Tor Hidden Services.

▪� Text editors

  🔸 Sublime Text - is a lightweight, cross-platform code editor known for its speed, ease of use.
  🔸 Visual Studio Code - an open-source and free source code editor developed by Microsoft.
  🔸 Atom - a hackable text editor for the 21st Century.

Web Tools  ^[TOC]

▪� Browsers

  🔸 SSL/TLS Capabilities of Your Browser - test your browser's SSL implementation.
  🔸 Can I use - provides up-to-date browser support tables for support of front-end web technologies.
  🔸 Panopticlick 3.0 - is your browser safe against tracking?
  🔸 Privacy Analyzer - see what data is exposed from your browser.
  🔸 Web Browser Security - it's all about Web Browser fingerprinting.
  🔸 How's My SSL? - help a web server developer learn what real world TLS clients were capable of.
  🔸 sslClientInfo - client test (incl TLSv1.3 information).

▪� SSL/Security

  🔸 SSLLabs Server Test - free online service performs a deep analysis of the configuration of any SSL web server.
  🔸 SSLLabs Server Test (DEV) - free online service performs a deep analysis of the configuration of any SSL web server.
  🔸 ImmuniWeb® SSLScan - test SSL/TLS (PCI DSS, HIPAA and NIST).
  🔸 COMODO SSL Analyzer - ssl analyzer and ssl certificate checker.*
  🔸 SSL Check - scan your website for non-secure content.
  🔸 CryptCheck - test your TLS server configuration (e.g. ciphers).
  🔸 urlscan.io - service to scan and analyse websites.
  🔸 Report URI - monitoring security policies like CSP and HPKP.
  🔸 CSP Evaluator - allows developers and security experts to check if a Content Security Policy.
  🔸 Useless CSP - public list about CSP in some big players (might make them care a bit more).
  🔸 Why No HTTPS? - list of the world's top 100 websites by Alexa rank not automatically redirecting insecure requests.
  🔸 cipherli.st - strong ciphers for Apache, Nginx, Lighttpd and more.
  🔸 dhtool - public Diffie-Hellman parameter service/tool.
  🔸 badssl.com - memorable site for testing clients against bad SSL configs.
  🔸 tlsfun.de - registered for various tests regarding the TLS/SSL protocol.
  🔸 CAA Record Helper - generate a CAA policy.
  🔸 Common CA Database - repository of information about CAs, and their root and intermediate certificates.
  🔸 CERTSTREAM - real-time certificate transparency log update stream.
  🔸 crt.sh - discovers certificates by continually monitoring all of the publicly known CT.
  🔸 Hardenize - deploy the security standards.
  🔸 Cipher suite compatibility - test TLS cipher suite compatibility.
  🔸 urlvoid - this service helps you detect potentially malicious websites.
  🔸 security.txt - a proposed standard (generator) which allows websites to define security policies.

▪� HTTP Headers & Web Linters

  🔸 Security Headers - analyse the HTTP response headers (with rating system to the results).
  🔸 Observatory by Mozilla - set of tools to analyze your website.
  🔸 webhint - is a linting tool that will help you with your site's accessibility, speed, security and more.

▪� DNS

  🔸 ViewDNS - one source for free DNS related tools and information.
  🔸 DNSLookup - is an advanced DNS lookup tool.
  🔸 DNSlytics - online DNS investigation tool.
  🔸 DNS Spy - monitor, validate and verify your DNS configurations.
  🔸 Zonemaster - helps you to control how your DNS works.
  🔸 Leaf DNS - comprehensive DNS tester.
  🔸 Find subdomains online - find subdomains for security assessment penetration test.
  🔸 DNSdumpster - dns recon & research, find & lookup dns records.
  🔸 DNS Table online - search for DNS records by domain, IP, CIDR, ISP.
  🔸 intoDNS - DNS and mail server health checker.
  🔸 DNS Bajaj - check the delegation of your domain.
  🔸 BuddyDNS Delegation LAB - check, trace and visualize delegation of your domain.
  🔸 dnssec-debugger - DS or DNSKEY records validator.
  🔸 PTRarchive.com - this site is responsible for the safekeeping of historical reverse DNS records.
  🔸 xip.io - wildcard DNS for everyone.
  🔸 dnslookup (ceipam) - one of the best DNS propagation checker (and not only).
  🔸 What's My DNS - DNS propagation checking tool.

▪� Mail

  🔸 MX Toolbox - all of your MX record, DNS, blacklist and SMTP diagnostics in one integrated tool.
  🔸 blacklistalert - checks to see if your domain is on a Real Time Spam Blacklist.
  🔸 MultiRBL - complete IP check for sending Mailservers.
  🔸 DKIM SPF & Spam Assassin Validator - checks mail authentication and scores messages with Spam Assassin.

▪� Encoders/Decoders and Regex testing

  🔸 URL Encode/Decode - tool from above to either encode or decode a string of text.
  🔸 Uncoder - the online translator for search queries on log data.
  🔸 Regex101 - online regex tester and debugger: PHP, PCRE, Python, Golang and JavaScript.
  🔸 RegExr - online tool to learn, build, & test Regular Expressions (RegEx / RegExp).
  🔸 RegEx Testing - online regex testing tool.
  🔸 RegEx Pal - online regex testing tool + other tools.
  🔸 The Cyber Swiss Army Knife - a web app for encryption, encoding, compression and data analysis.

▪� Net-tools

  🔸 Netcraft - detailed report about the site, helping you to make informed choices about their integrity.*
  🔸 RIPE NCC - not-for-profit membership association, a Regional Internet Registry and the secretariat for the RIPE.
  🔸 Robtex - uses various sources to gather public information about IP numbers, domain names, host names, routes etc.
  🔸 Security Trails - APIs for Security Companies, Researchers and Teams.
  🔸 Online Curl - curl test, analyze HTTP Response Headers.
  🔸 Ping.eu - online Ping, Traceroute, DNS lookup, WHOIS and others.
  🔸 Network-Tools - network tools for webmasters, IT technicians & geeks.
  🔸 Riseup - provides online communication tools for people and groups working on liberatory social change.
  🔸 VirusTotal - analyze suspicious files and URLs to detect types of malware.

▪� Privacy

  🔸 privacytools.io - provides knowledge and tools to protect your privacy against global mass surveillance.
  🔸 DNS Privacy Test Servers - DNS privacy recursive servers list (with a 'no logging' policy).

▪� Code parsers/playgrounds

  🔸 ShellCheck - finds bugs in your shell scripts.
  🔸 explainshell - get interactive help texts for shell commands.
  🔸 jsbin - live pastebin for HTML, CSS & JavaScript and more.
  🔸 CodeSandbox - online code editor for web application development. Supports React, Vue, Angular, CxJS, Dojo, etc.
  🔸 PHP Sandbox - test your PHP code with this code tester.
  🔸 Repl.it - an instant IDE to learn, build, collaborate, and host all in one place.

▪� Performance

  🔸 GTmetrix - analyze your site’s speed and make it faster.
  🔸 Sucuri loadtimetester - test here the performance of any of your sites from across the globe.
  🔸 Pingdom Tools - analyze your site’s speed around the world.
  🔸 PingMe.io - run website latency tests across multiple geographic regions.
  🔸 PageSpeed Insights - analyze your site’s speed and make it faster.
  🔸 web.dev - helps developers like you learn and apply the web's modern capabilities to your own sites and apps.

▪� Mass scanners (search engines)

  🔸 Censys - platform that helps information security practitioners discover, monitor, and analyze devices.
  🔸 Shodan - the world's first search engine for Internet-connected devices.
  🔸 Shodan 2000 - do you use Shodan for everyday work? This tool looks for randomly generated data from Shodan.
  🔸 GreyNoise - mass scanner such as Shodan and Censys.
  🔸 ZoomEye - search engine for cyberspace that lets the user find specific network components.
  🔸 netograph - tools to monitor and understand deep structure of the web.
  🔸 FOFA - is a cyberspace search engine.
  🔸 onyphe - is a search engine for open-source and cyber threat intelligence data collected.
  🔸 IntelligenceX - is a search engine and data archive.
  🔸 binaryedge - it scan the entire internet space and create real-time threat intelligence streams and reports.
  🔸 wigle - is a submission-based catalog of wireless networks. All the networks. Found by Everyone.
  🔸 PublicWWW - find any alphanumeric snippet, signature or keyword in the web pages HTML, JS and CSS code.
  🔸 IntelTechniques - this repository contains hundreds of online search utilities.
  🔸 Hackle - search engine for hackers and security professionals.*
  🔸 hunter - lets you find email addresses in seconds and connect with the people that matter for your business.
  🔸 GhostProject? - search by full email address or username.
  🔸 databreaches - was my email affected by data breach?
  🔸 Buckets by Grayhatwarfar - database with public search for Open Amazon S3 Buckets and their contents.
  🔸 Vigilante.pw - the breached database directory.
  🔸 builtwith - find out what websites are built with.
  🔸 Mamont's open FTP Index - if a target has an open FTP site with accessible content it will be listed here.
  🔸 OSINT Framework - focused on gathering information from free tools or resources.
  🔸 maltiverse - is a service oriented to cybersecurity analysts for the advanced analysis of indicators of compromise.
  🔸 Leaked Source - is a collaboration of data found online in the form of a lookup.
  🔸 We Leak Info - to help everyday individuals secure their online life, avoiding getting hacked.
  🔸 pipl - is the place to find the person behind the email address, social username or phone number.
  🔸 abuse.ch - is operated by a random swiss guy fighting malware for non-profit.
  🔸 malc0de - malware search engine.
  🔸 Cybercrime Tracker - monitors and tracks various malware families that are used to perpetrate cyber crimes.
  🔸 NerdyData - search source code across 65 million websites.
  🔸 searchcode - helping you find real world examples of functions, API's and libraries.
  🔸 Insecam - the world biggest directory of online surveillance security cameras.
  🔸 index-of - contains great stuff like: security, hacking, reverse engineering, cryptography, programming etc.

▪� Generators

  🔸 thispersondoesnotexist - generate fake faces in one click - endless possibilities.
  🔸 Intigriti Redirector - open redirect/SSRF payload generator.

▪� Passwords

  🔸 Gotcha? - list of 1.4 billion accounts circulates around the Internet.*
  🔸 have i been pwned? - check if you have an account that has been compromised in a data breach.

▪� CVE/Exploits databases

  🔸 CVE Mitre - list of publicly known cybersecurity vulnerabilities.
  🔸 CVE Details - CVE security vulnerability advanced database.
  🔸 Exploit DB - CVE compliant archive of public exploits and corresponding vulnerable software.
  🔸 0day.today - exploits market provides you the possibility to buy zero-day exploits and also to sell 0day exploits.
  🔸 sploitus - the exploit and tools database.
  🔸 cxsecurity - free vulnerability database.
  🔸 Vulncode-DB - is a database for vulnerabilities and their corresponding source code if available.
  🔸 cveapi - free API for CVE data.

▪� Mobile apps scanners

  🔸 ImmuniWeb® Mobile App Scanner - test security and privacy of mobile apps (iOS & Android).
  🔸 Quixxi - free Mobile App Vulnerability Scanner for Android & iOS.
  🔸 Ostorlab - analyzes mobile application to identify vulnerabilities and potential weaknesses.

▪� Private Search Engines

  🔸 Startpage - the world's most private search engine.
  🔸 searX - a privacy-respecting, hackable metasearch engine.
  🔸 darksearch - the 1st real Dark Web search engine.

▪� Secure WebMail Providers

  🔸 CounterMail - is a secure and easy to use online email service, designed to provide maximum security and privacy.
  🔸 Mail2Tor - is a Tor Hidden Service that allows anyone to send and receive emails anonymously.
  🔸 Tutanota - is the world's most secure email service and amazingly easy to use.
  🔸 Protonmail - is the world's largest secure email service, developed by CERN and MIT scientists.
  🔸 Startmail - private & encrypted email made easy.

▪� Crypto

  🔸 Keybase - it's open source and powered by public-key cryptography.

▪� PGP Keyservers

  🔸 SKS OpenPGP Key server - services for the SKS keyservers used by OpenPGP.

Systems/Services  ^[TOC]

▪� Operating Systems

  🔸 Slackware - the most "Unix-like" Linux distribution.
  🔸 OpenBSD - multi-platform 4.4BSD-based UNIX-like operating system.
  🔸 HardenedBSD - HardenedBSD aims to implement innovative exploit mitigation and security solutions.
  🔸 Kali Linux - Linux distribution used for Penetration Testing, Ethical Hacking and network security assessments.
  🔸 Pentoo - is a security-focused livecd based on Gentoo.
  🔸 Backbox Linux - penetration test and security assessment oriented Ubuntu-based Linux distribution.
  🔸 BlackArch - is an Arch Linux-based penetration testing distribution for penetration testers and security researchers.
  🔸 Security Onion - Linux distro for intrusion detection, enterprise security monitoring, and log management.
  🔸 Tails - is a live system that aims to preserve your privacy and anonymity.

▪� HTTP(s) Services

  🔸 Varnish Cache - HTTP accelerator designed for content-heavy dynamic web sites.
  🔸 Nginx - open source web and reverse proxy server that is similar to Apache, but very light weight.
  🔸 Tengine - a distribution of Nginx with some advanced features.
  🔸 Caddy Server - is an open source, HTTP/2-enabled web server with HTTPS by default.
  🔸 HAProxy - the reliable, high performance TCP/HTTP load balancer.
  🔸 Traefik - open source reverse proxy/load balancer provides easier integration with Docker and Let's encrypt.

▪� DNS Services

  🔸 Unbound - validating, recursive, and caching DNS resolver (with TLS).
  🔸 Knot Resolver - caching full resolver implementation, including both a resolver library and a daemon.
  🔸 PowerDNS - is an open source authoritative DNS server, written in C++ and licensed under the GPL.

▪� Other Services

  🔸 3proxy - tiny free proxy server.

▪� Security/hardening

  🔸 Emerald Onion - is a 501(c)(3) nonprofit organization and transit internet service provider (ISP) based in Seattle.
  🔸 pi-hole - the Pi-hole® is a DNS sinkhole that protects your devices from unwanted content.
  🔸 maltrail - malicious traffic detection system.
  🔸 security_monkey - monitors AWS, GCP, OpenStack, and GitHub orgs for assets and their changes over time.
  🔸 firecracker - secure and fast microVMs for serverless computing.

Networks  ^[TOC]

▪� Tools

  🔸 CapAnalysis - web visual tool to analyze large amounts of captured network traffic (PCAP analyzer).
  🔸 netbox - IP address management (IPAM) and data center infrastructure management (DCIM) tool.

▪� Labs

  🔸 NRE Labs - learn automation by doing it. Right now, right here, in your browser.

▪� Other

  🔸 LBNL's Network Research Group - home page of the Network Research Group (NRG); tools, talks, papers and more.

Manuals/Howtos/Tutorials  ^[TOC]

▪� Shell/Command line

  🔸 pure-bash-bible - a collection of pure bash alternatives to external processes.
  🔸 The Bash Hackers Wiki - hold documentation of any kind about GNU Bash.
  🔸 Shell & Utilities - describes the commands and utilities offered to application programs by POSIX-conformant systems.
  🔸 the-art-of-command-line - master the command line, in one page.
  🔸 Shell Style Guide - a shell style guide for Google-originated open-source projects.

▪� Text Editors

  🔸 Vim Cheat Sheet - great multi language vim guide.

▪� Python

  🔸 Awesome Python - a curated list of awesome Python frameworks, libraries, software and resources.
  🔸 python-cheatsheet - comprehensive Python cheatsheet.

▪� Sed & Awk & Other

  🔸 F’Awk Yeah! - advanced sed and awk usage (Parsing for Pentesters 3).

▪� *nix & Network

  🔸 nixCraft - linux and unix tutorials for new and seasoned sysadmin.
  🔸 TecMint - the ideal Linux blog for Sysadmins & Geeks.
  🔸 Omnisecu - free Networking, System Administration and Security tutorials.
  🔸 linux-cheat - Linux tutorials and cheatsheets. Minimal examples. Mostly user-land CLI utilities.
  🔸 Unix Toolbox - collection of Unix/Linux/BSD commands and tasks which are useful for IT work or for advanced users.
  🔸 Linux Guide and Hints - tutorials on system administration in Fedora and CentOS.
  🔸 strace-little-book - a little book which introduces strace.
  🔸 http2-explained - a detailed document explaining and documenting HTTP/2.
  🔸 http3-explained - a document describing the HTTP/3 and QUIC protocols.
  🔸 Nginx Admin's Handbook - describes how to improve NGINX performance, security and other important things.
  🔸 openssh guideline - is to help operational teams with the configuration of OpenSSH server and client.
  🔸 PacketLife.net - a place to record notes while studying for Cisco's CCNP certification.

▪� Large-scale systems

  🔸 The System Design Primer - learn how to design large-scale systems.
  🔸 Awesome Scalability - best practices in building High Scalability, High Availability, High Stability and more.
  🔸 Web Architecture 101 - the basic architecture concepts.

▪� System hardening

  🔸 CIS Benchmarks - are secure configuration settings for over 100 technologies, available as a free PDF download.
  🔸 STIGs - are the configuration standards for DOD IA and IA-enabled devices/systems.
  🔸 Security Harden CentOS 7 - this walks you through the steps required to security harden CentOS.
  🔸 CentOS 7 Server Hardening Guide - great guide for hardening CentOS; familiar with OpenSCAP.
  🔸 The Practical Linux Hardening Guide - provides a high-level overview of hardening GNU/Linux systems.

▪� Security & Privacy

  🔸 Hacking Articles - LRaj Chandel's Security & Hacking Blog.
  🔸 AWS security tools - make your AWS cloud environment more secure.
  🔸 Rawsec's CyberSecurity Inventory - an inventory of tools and resources about CyberSecurity.
  🔸 The Illustrated TLS Connection - every byte of a TLS connection explained and reproduced.
  🔸 SSL Research - SSL and TLS Deployment Best Practices by SSL Labs.
  🔸 Certificates and PKI - everything you should know about certificates and PKI but are too afraid to ask.
  🔸 The Art of Subdomain Enumeration - a reference for subdomain enumeration techniques.
  🔸 Quitting Google - the comprehensive guide to quitting Google.

▪� Web Apps

  🔸 OWASP - worldwide not-for-profit charitable organization focused on improving the security of software.
  🔸 OWASP ASVS 3.0.1 - OWASP Application Security Verification Standard Project.
  🔸 OWASP ASVS 3.0.1 Web App - simple web app that helps developers understand the ASVS requirements.
  🔸 OWASP ASVS 4.0 - is a list of application security requirements or tests.
  🔸 OWASP Testing Guide v4 - includes a "best practice" penetration testing framework.
  🔸 OWASP Dev Guide - this is the development version of the OWASP Developer Guide.
  🔸 Mozilla Web Security - help operational teams with creating secure web applications.
  🔸 security-bulletins - security bulletins that relate to Netflix Open Source.
  🔸 Enable CORS - enable cross-origin resource sharing.
  🔸 Application Security Wiki - is an initiative to provide all application security related resources at one place.
  🔸 Weird Proxies - reverse proxy related attacks; it is a result of analysis of various reverse proxies, cache proxies, etc.
  🔸 Webshells - great series about malicious payloads.
  🔸 Practical Web Cache Poisoning - show you how to compromise websites by using esoteric web features.
  🔸 Hidden directories and files - as a source of sensitive information about web application.
  🔸 Explosive blog - great blog about cybersec and pentests.
  🔸 Security Cookies - this paper will take a close look at cookie security.
  🔸 APISecurityBestPractices - help you keep secrets (API keys, db credentials, certificates) out of source code.

▪� All-in-one

  🔸 LZone Cheat Sheets - all cheat sheets.
  🔸 Dan’s Cheat Sheets’s - massive cheat sheets documentation.
  🔸 Rico's cheatsheets - this is a modest collection of cheatsheets.
  🔸 DevDocs API - combines multiple API documentations in a fast, organized, and searchable interface.

▪� Other

  🔸 CTF Series : Vulnerable Machines - the steps below could be followed to find vulnerabilities and exploits.
  🔸 50M_CTF_Writeup - $50 million CTF from Hackerone - writeup.
  🔸 ctf-tasks - an archive of low-level CTF challenges developed over the years.
  🔸 How to start RE/malware analysis? - collection of some hints and useful links for the beginners.
  🔸 The C10K problem - it's time for web servers to handle ten thousand clients simultaneously, don't you think?
  🔸 poor man's profiler - sampling tools like dtrace's don't really provide methods to see what programs are blocking on.
  🔸 Bank Grade Security - when companies say they have "Bank Grade Security" they imply that it is a good thing.*
  🔸 HTTPS on Stack Overflow - this is the story of a long journey regarding the implementation of SSL.
  🔸 Julia's Drawings - some drawings about programming and unix world, zines about systems & debugging tools.
  🔸 Hash collisions - this great repository is focused on hash collisions exploitation.
  🔸 BGP Meets Cat - after 3072 hours of manipulating BGP, Job Snijders has succeeded in drawing a Nyancat.
  🔸 What happens when... - you type google.com into your browser and press enter?
  🔸 how-web-works - based on the 'What happens when...' repository.
  🔸 HTTPS in the real world - great tutorial explain how HTTPS works in the real world.
  🔸 Gitlab and NFS bug - how we spent two weeks hunting an NFS bug in the Linux kernel.
  🔸 How To Become A Hacker - if you want to be a hacker, keep reading.
  🔸 Operation Costs in CPU - an infographics which should help to estimate costs of certain operations in CPU clocks.
  🔸 Let's Build a Simple Database - writing a sqlite clone from scratch in C.
  🔸 simple-computer - great resource to understand how computers work under the hood.
  🔸 The story of "Have I been pwned?" - working with 154 million records on Azure Table Storage.
  🔸 TOP500 Supercomputers - shows the 500 most powerful commercially available computer systems known to us.

Inspiring Lists  ^[TOC]

▪� SysOps/DevOps

  🔸 Awesome Sysadmin - amazingly awesome open source sysadmin resources.
  🔸 Awesome Shell - awesome command-line frameworks, toolkits, guides and gizmos.
  🔸 Command-line-text-processing - from finding text to search and replace, from sorting to beautifying text and more.
  🔸 Awesome Pcaptools - collection of tools developed by other researchers to process network traces.
  🔸 awesome-ebpf - a curated list of awesome projects related to eBPF.
  🔸 Linux Network Performance - learn where some of the network sysctl variables fit into the Linux/Kernel network flow.
  🔸 Awesome Postgres - list of awesome PostgreSQL software, libraries, tools and resources.
  🔸 quick-SQL-cheatsheet - a quick reminder of all SQL queries and examples on how to use them.
  🔸 Awesome-Selfhosted - list of Free Software network services and web applications which can be hosted locally.
  🔸 kubernetes-the-hard-way - bootstrap Kubernetes the hard way on Google Cloud Platform. No scripts.
  🔸 kubernetes-the-easy-way - bootstrap Kubernetes the easy way on Google Cloud Platform. No scripts.
  🔸 List of applications - huge collection of applications sorted by category, as a reference for those looking for packages.

▪� Developers

  🔸 Front-End-Checklist - the perfect Front-End Checklist for modern websites and meticulous developers.
  🔸 Python's Magic Methods - what are magic methods? They're everything in object-oriented Python.
  🔸 wtfpython - a collection of surprising Python snippets and lesser-known features.
  🔸 js-dev-reads - a list of books and articles for the discerning web developer to read.
  🔸 Commit messages guide - a guide to understand the importance of commit messages.

▪� Security/Pentesting

  🔸 Awesome Web Security - a curated list of Web Security materials and resources.
  🔸 awesome-cyber-skills - a curated list of hacking environments where you can train your cyber skills.
  🔸 awesome-threat-intelligence - a curated list of Awesome Threat Intelligence resources.
  🔸 Red-Teaming-Toolkit - a collection of open source and commercial tools that aid in red team operations.
  🔸 awesome-burp-extensions - a curated list of amazingly awesome Burp Extensions.
  🔸 Free Security eBooks - list of a Free Security and Hacking eBooks.
  🔸 reverse-engineering - list of awesome reverse engineering resources.
  🔸 linux-re-101 - a collection of resources for linux reverse engineering.
  🔸 reverseengineering-reading-list - a list of Reverse Engineering articles, books, and papers.
  🔸 Awesome-WAF - a curated list of awesome web-app firewall (WAF) stuff.
  🔸 RobotsDisallowed - a curated list of the most common and most interesting robots.txt disallowed directories.
  🔸 awesome-yara - a curated list of awesome YARA rules, tools, and people.
  🔸 Movies for Hackers - list of movies every hacker & cyberpunk must watch.
  🔸 technical-whitepapers - IT whitepapers; hacking, web app security, db, reverse engineering and more; EN/PL.

▪� Other

  🔸 Cheatography - over 3,000 free cheat sheets, revision aids and quick references.
  🔸 awesome-static-analysis - static analysis tools for all programming languages.

Blogs/Podcasts/Videos  ^[TOC]

▪� SysOps/DevOps

  🔸 Varnish for PHP developers - very interesting presentation of Varnish by Mattias Geniar.
  🔸 A Netflix Guide to Microservices - Josh Evans talks about the chaotic and vibrant world of microservices at Netflix.

▪� Developers

  🔸 Comparing C to machine language - compare a simple C program with the compiled machine code of that program.

▪� Geeky Persons

  🔸 Brendan Gregg's Blog - is an industry expert in computing performance and cloud computing.
  🔸 Gynvael "GynDream" Coldwind - is a IT security engineer at Google.
  🔸 Michał "lcamtuf" Zalewski - white hat hacker, computer security expert.
  🔸 Mattias Geniar - developer, sysadmin, blogger, podcaster and public speaker.
  🔸 Nick Craver - software developer and systems administrator for Stack Exchange.
  🔸 Scott Helme - security researcher, international speaker and founder of securityheaders.com and report-uri.com.
  🔸 Brian Krebs - The Washington Post and now an Independent investigative journalist.
  🔸 Bruce Schneier - is an internationally renowned security technologist, called a "security guru".
  🔸 Chrissy Morgan - advocate of practical learning, Chrissy also takes part in bug bounty programs.
  🔸 Andy Gill - is a hacker at heart who works as a senior penetration tester.
  🔸 Daniel Miessler - cybersecurity expert and writer.
  🔸 Javvad Malik - is a security advocate at AlienVault, a blogger event speaker and industry commentator.
  🔸 Graham Cluley - public speaker and independent computer security analyst.
  🔸 Kacper Szurek - detection engineer at ESET.
  🔸 Troy Hunt - web security expert known for public education and outreach on security topics.
  🔸 raymii.org - sysadmin specializing in building high availability cloud environments.
  🔸 Robert Penz - IT security expert.

▪� Geeky Blogs

  🔸 Linux Audit - the Linux security blog about auditing, hardening and compliance by Michael Boelen.
  🔸 Linux Security Expert - trainings, howtos, checklists, security tools and more.
  🔸 The Grymoire - collection of useful incantations for wizards, be you computer wizards, magicians, or whatever.
  🔸 PortSwigger Web Security Blog - about web app security vulns and top tips from our team of web security.
  🔸 Secjuice - is the only non-profit, independent and volunteer led publication in the information security space.
  🔸 Decipher - security news that informs and inspires.

▪� Geeky Vendor Blogs

  🔸 Tenable Podcast - conversations and interviews related to Cyber Exposure, and more.
  🔸 Sophos - threat news room, giving you news, opinion, advice and research on computer security issues.
  🔸 Tripwire State of Security - blog featuring the latest news, trends and insights on current information security issues.
  🔸 Malwarebytes Labs Blog - security blog aims to provide insider news about cybersecurity.
  🔸 TrustedSec - latest news, and trends about cybersecurity.
  🔸 AT&T Cybersecurity blog - news on emerging threats and practical advice to simplify threat detection.
  🔸 Thycotic - where CISOs and IT Admins come to learn about industry trends, IT security, data breaches, and more.

▪� Geeky Cybersecurity Podcasts

  🔸 Risky Business - is a weekly information security podcast featuring news and in-depth interviews.
  🔸 Cyber, by Motherboard - stories, and focus on the ideas about cybersecurity.
  🔸 Tenable Podcast - conversations and interviews related to Cyber Exposure, and more.
  🔸 Cybercrime Investigations - podcast by Geoff White about cybercrimes.
  🔸 The many hats club - featuring stories from a wide range of Infosec people (Whitehat, Greyhat and Blackhat).
  🔸 Darknet Diaries - true stories from the dark side of the Internet.
  🔸 OSINTCurious Webcasts - is the investigative curiousity that helps people be successful in OSINT.

▪� Geeky Cybersecurity Video Blogs

  🔸 rev3rse security - offensive, binary exploitation, web application security, vulnerability, hardening, red team, blue team.
  🔸 LiveOverflow - a lot more advanced topics than what is typically offered in paid online courses - but for free.
  🔸 J4vv4D - the important information regarding our internet security.
  🔸 CyberTalks - talks, interviews, and article about cybersecurity.

▪� Best Personal Twitter Accounts

  🔸 @blackroomsec - a white-hat hacker/pentester. Intergalactic Minesweeper Champion 1990.
  🔸 @MarcoCiappelli - Co-Founder @ITSPmagazine, at the intersection of IT security and society.
  🔸 @binitamshah - Linux Evangelist. Malwares. Kernel Dev. Security Enthusiast.
  🔸 @joe_carson - an InfoSec Professional and Tech Geek.
  🔸 @mikko - CRO at F-Secure, Reverse Engineer, TED Speaker, Supervillain.
  🔸 @esrtweet - often referred to as ESR, is an American software developer, and open-source software advocate.
  🔸 @gynvael - security researcher/programmer, @DragonSectorCTF founder/player, technical streamer.
  🔸 @x0rz - Security Researcher & Cyber Observer.
  🔸 @hasherezade - programmer, malware analyst. Author of PEbear, PEsieve, libPeConv.
  🔸 @TinkerSec - tinkerer, cypherpunk, hacker.
  🔸 @alisaesage - independent hacker and researcher.

▪� Best Commercial Twitter Accounts

  🔸 @haveibeenpwned - check if you have an account that has been compromised in a data breach.
  🔸 @bugcrowd - trusted by more of the Fortune 500 than any other crowdsourced security platform.
  🔸 @Malwarebytes - most trusted security company. Unmatched threat visibility.
  🔸 @sansforensics - the world's leading Digital Forensics and Incident Response provider.
  🔸 @attcyber - AT&T Cybersecurity’s Edge-to-Edge technologies provide threat intelligence, and more.
  🔸 @TheManyHatsClub - an information security focused podcast and group of individuals from all walks of life.
  🔸 @hedgehogsec - Hedgehog Cyber. Gibraltar and Manchester's top boutique information security firm.
  🔸 @NCSC - the National Cyber Security Centre. Helping to make the UK the safest place to live and work online.
  🔸 @Synacktiv - IT security experts.

▪� A piece of history

  🔸 How to Do Things at ARL - how to configure modems, scan images, record CD-ROMs, and other useful techniques.*

▪� Other

  🔸 Diffie-Hellman Key Exchange (short version) - how Diffie-Hellman Key Exchange worked.

Hacking/Penetration Testing  ^[TOC]

▪� Pentesters arsenal tools

  🔸 Sandcat Browser - a penetration-oriented browser with plenty of advanced functionality already built in.
  🔸 Metasploit - tool and framework for pentesting system, web and many more, contains a lot a ready to use exploit.
  🔸 Burp Suite - tool for testing web application security, intercepting proxy to replay, inject, scan and fuzz HTTP requests.
  🔸 OWASP Zed Attack Proxy - intercepting proxy to replay, inject, scan and fuzz HTTP requests.
  🔸 w3af - is a Web Application Attack and Audit Framework.
  ��”¸ mitmproxy - an interactive TLS-capable intercepting HTTP proxy for penetration testers and software developers.
  🔸 Nikto2 - web server scanner which performs comprehensive tests against web servers for multiple items.
  🔸 sqlmap - tool that automates the process of detecting and exploiting SQL injection flaws.
  🔸 Faraday - an Integrated Multiuser Pentest Environment.
  🔸 Photon - incredibly fast crawler designed for OSINT.
  🔸 XSStrike - most advanced XSS detection suite.
  🔸 Sn1per - automated pentest framework for offensive security experts.
  🔸 aquatone - a tool for domain flyovers.
  🔸 BillCipher - information gathering tool for a website or IP address.
  🔸 WhatWaf - detect and bypass web application firewalls and protection systems.
  🔸 John The Ripper - is a fast password cracker, currently available for many flavors of Unix, Windows, and other.
  🔸 hashcat - world's fastest and most advanced password recovery utility.
  🔸 p0f - is a tool to identify the players behind any incidental TCP/IP communications.
  🔸 Recon-ng - is a full-featured Web Reconnaissance framework written in Python.
  🔸 ssh_scan - a prototype SSH configuration and policy scanner.
  🔸 LeakLooker - find open databases - powered by Binaryedge.io
  🔸 exploitdb - searchable archive from The Exploit Database.
  🔸 ctf-tools - some setup scripts for security research tools.
  🔸 pwntools - CTF framework and exploit development library.
  🔸 security-tools - collection of small security tools created mostly in Python. CTFs, pentests and so on.
  🔸 fuzzdb - dictionary of attack patterns and primitives for black-box application fault injection and resource discovery.
  🔸 syzkaller - is an unsupervised, coverage-guided kernel fuzzer.
  🔸 pwndbg - exploit development and reverse engineering with GDB made easy.
  🔸 GDB PEDA - Python Exploit Development Assistance for GDB.
  🔸 IDA - multi-processor disassembler and debugger useful for reverse engineering malware.
  🔸 radare2 - framework for reverse-engineering and analyzing binaries.
  🔸 routersploit - exploitation framework for embedded devices.
  🔸 Ghidra - is a software reverse engineering (SRE) framework.
  🔸 Vulnreport - open-source pentesting management and automation platform by Salesforce Product Security.
  🔸 Mentalist - is a graphical tool for custom wordlist generation.
  🔸 archerysec - vulnerability assessment and management helps to perform scans and manage vulnerabilities.
  🔸 Osmedeus - fully automated offensive security tool for reconnaissance and vulnerability scanning.
  🔸 beef - the browser exploitation framework project.
  🔸 AutoSploit - automated mass exploiter.

▪� Backdoors/exploits

  🔸 PHP-backdoors - a collection of PHP backdoors. For educational or testing purposes only.

▪� Pentests bookmarks collection

  🔸 PTES - the penetration testing execution standard.
  🔸 Pentests MindMap - amazing mind map with vulnerable apps and systems.
  🔸 WebApps Security Tests MindMap - incredible mind map for WebApps security tests.
  🔸 Brute XSS - master the art of Cross Site Scripting.
  🔸 Offensive Security Bookmarks - security bookmarks collection, all that things I need to pass OSCP.
  🔸 Awesome Pentest Cheat Sheets - collection of the cheat sheets useful for pentesting.
  🔸 Awesome Hacking by HackWithGithub - awesome lists for hackers, pentesters and security researchers.
  🔸 Awesome Hacking by carpedm20 - a curated list of awesome hacking tutorials, tools and resources.
  🔸 Awesome Hacking Resources - collection of hacking/penetration testing resources to make you better.
  🔸 Awesome Pentest - collection of awesome penetration testing resources, tools and other shiny things.
  🔸 Hacking Cheat Sheet - author hacking and pentesting notes.
  🔸 Web App Pentesting Cheat Sheet - the typical steps performed when conducting a web application penetration test.*
  🔸 Cyber Security Resources - includes thousands of cybersecurity-related references and resources.
  🔸 Pentest Bookmarks - there are a LOT of pentesting blogs.
  🔸 PayloadsAllTheThings - a list of useful payloads and bypass for Web Application Security and Pentest/CTF.
  🔸 payloads - git all the Payloads! A collection of web attack payloads.
  🔸 Pentesting Tools Cheat Sheet - a quick reference high level overview for typical penetration testing engagements.
  🔸 OWASP Cheat Sheet Series - is a collection of high value information on specific application security topics.
  🔸 OWASP dependency-check - is an open source solution the OWASP Top 10 2013 entry.
  🔸 DEF CON Media Server - great stuff from DEFCON.
  🔸 Awesome Malware Analysis - a curated list of awesome malware analysis tools and resources.
  🔸 SQL Injection Cheat Sheet - detailed technical information about the many different variants of the SQL Injection.
  🔸 Entersoft Knowledge Base - great and detailed reference about vulnerabilities.
  🔸 HTML5 Security Cheatsheet - a collection of HTML5 related XSS attack vectors.
  🔸 XSS String Encoder - for generating XSS code to check your input validation filters against XSS.
  🔸 GTFOBins - list of Unix binaries that can be exploited by an attacker to bypass local security restrictions.
  🔸 Guifre Ruiz Notes - collection of security, system, network and pentest cheatsheets.
  🔸 SSRF Tips - a collection of SSRF Tips.
  🔸 shell-storm repo CTF - great archive of CTFs.
  🔸 ctf - CTF (Capture The Flag) writeups, code snippets, notes, scripts.
  🔸 My-CTF-Web-Challenges - collection of CTF Web challenges.
  🔸 MSTG - The Mobile Security Testing Guide (MSTG) is a comprehensive manual for mobile app security testing.
  🔸 Internal-Pentest-Playbook - notes on the most common things for an Internal Network Penetration Test.

▪� Wordlists and Weak passwords

  🔸 Weakpass - for any kind of bruteforce find wordlists or unleash the power of them all at once!
  🔸 Hashes.org - is a free online hash resolving service incorporating many unparalleled techniques.
  🔸 SecLists - collection of multiple types of lists used during security assessments, collected in one place.
  🔸 Probable-Wordlists - sorted by probability originally created for password generation and testing.
  🔸 skullsecurity passwords - password dictionaries and leaked passwords repository.
  🔸 Polish PREMIUM Dictionary - official dictionary created by the team on the forum bezpieka.org.* ¹

▪� Bounty platforms

  🔸 YesWeHack - bug bounty platform with infosec jobs.
  🔸 Openbugbounty - allows any security researcher reporting a vulnerability on any website.
  🔸 hackerone - global hacker community to surface the most relevant security issues.
  🔸 bugcrowd - crowdsourced cybersecurity for the enterprise.
  🔸 Crowdshield - crowdsourced security & bug bounty management.
  🔸 Synack - crowdsourced security & bug bounty programs, crowd security intelligence platform and more.
  🔸 Hacktrophy - bug bounty platform.

▪� Web Training Apps (local installation)

  🔸 OWASP-VWAD - comprehensive and well maintained registry of all known vulnerable web applications.
  🔸 Metasploitable 2 - vulnerable web application amongst security researchers.
  🔸 DVWA - PHP/MySQL web application that is damn vulnerable.
  🔸 OWASP Mutillidae II - free, open source, deliberately vulnerable web-application.
  🔸 OWASP Juice Shop Project - the most bug-free vulnerable application in existence.
  🔸 juicy-ctf - run Capture the Flags and Security Trainings with OWASP Juice Shop.
  🔸 OWASP WebGoat Project - insecure web application maintained by OWASP designed to teach web app security.
  🔸 Security Ninjas - open source application security training program.
  🔸 hackazon - a modern vulnerable web app.
  🔸 dvna - damn vulnerable NodeJS application.
  🔸 Google Gruyere - web application exploits and defenses.
  🔸 Bodhi - is a playground focused on learning the exploitation of client-side web vulnerabilities.
  🔸 Websploit - single vm lab with the purpose of combining several vulnerable appliations in one environment.
  🔸 vulhub - pre-built Vulnerable Environments based on docker-compose.
  🔸 CloudGoat 2 - the new & improved "Vulnerable by Design" AWS deployment tool.

▪� Labs (ethical hacking platforms/trainings/CTFs)

  🔸 Offensive Security - true performance-based penetration testing training for over a decade.
  🔸 Hack The Box - online platform allowing you to test your penetration testing skills.
  🔸 Hacking-Lab - online ethical hacking, computer network and security challenge platform.
  🔸 pwnable.kr - non-commercial wargame site which provides various pwn challenges regarding system exploitation.
  🔸 Pwnable.tw - is a wargame site for hackers to test and expand their binary exploiting skills.
  🔸 picoCTF - is a free computer security game targeted at middle and high school students.
  🔸 CTFlearn - is an online platform built to help ethical hackers learn and practice their cybersecurity knowledge and skills.
  🔸 ctftime - CTF archive and a place, where you can get some another CTF-related info.
  🔸 Silesia Security Lab - high quality security testing services.
  🔸 Practical Pentest Labs - pentest lab, take your Hacking skills to the next level.
  🔸 Root Me - the fast, easy, and affordable way to train your hacking skills.
  🔸 rozwal.to - a great platform to train your pentesting skills.
  🔸 TryHackMe - learning Cyber Security made easy.
  🔸 hackxor - is a realistic web application hacking game, designed to help players of all abilities develop their skills.
  🔸 Hack Yourself First - it's full of nasty app sec holes.
  🔸 OverTheWire - can help you to learn and practice security concepts in the form of fun-filled games.
  🔸 Wizard Labs - is an online Penetration Testing Lab.
  🔸 PentesterLab - provides vulnerable systems that can be used to test and understand vulnerabilities.
  🔸 RingZer0 - tons of challenges designed to test and improve your hacking skills.
  🔸 Ubeeri - preconfigured lab environments.
  🔸 Pentestit - emulate IT infrastructures of real companies for legal pen testing and improving penetration testing skills.
  🔸 Microcorruption - reversal challenges done in the web interface.
  🔸 Crackmes - download crackmes to help improve your reverse engineering skills.
  🔸 DomGoat - DOM XSS security learning and practicing platform.
  🔸 Stereotyped Challenges - upgrade your web hacking techniques today!
  🔸 OverTheWire - can help you to learn and practice security concepts in the form of fun-filled games.
  🔸 Vulnhub - allows anyone to gain practical 'hands-on' experience in digital security.
  🔸 W3Challs - is a penetration testing training platform, which offers various computer challenges.
  🔸 RingZer0 CTF - offers you tons of challenges designed to test and improve your hacking skills.
  🔸 try2hack - several security-oriented challenges for your entertainment.
  🔸 Hack.me - a platform where you can build, host and share vulnerable web apps for educational and research purposes.
  🔸 HackThis! - discover how hacks, dumps and defacements are performed and secure your website against hackers.
  🔸 Enigma Group WebApp Training - these challenges cover the exploits listed in the OWASP Top 10 Project.
  🔸 Reverse Engineering Challenges - challenges, exercises, problems and tasks - by level, by type, and more.
  🔸 0x00sec - the home of the Hacker - Malware, Reverse Engineering, and Computer Science.
  🔸 We Chall - there are exist a lots of different challenge types.
  🔸 Hacker Gateway - is the go-to place for hackers who want to test their skills.
  🔸 Hacker101 - is a free class for web security.
  🔸 contained.af - a stupid game for learning about containers, capabilities, and syscalls.
  🔸 flAWS challenge! - a series of levels you'll learn about common mistakes and gotchas when using AWS.

▪� Other resources

  🔸 Bugcrowd University - open source education content for the researcher community.
  🔸 OSCPRepo - a list of resources and scripts that I have been gathering in preparation for the OSCP.
  🔸 OWASP Top 10: Real-World Examples - test your web apps with real-world examples (two-part series).

Your daily knowledge and news  ^[TOC]

▪� RSS Readers

  🔸 Feedly - organize, read and share what matters to you.
  🔸 Inoreader - similar to feedly with a support for filtering what you fetch from rss.

▪� IRC Channels

  🔸 #hackerspaces - hackerspace IRC channels.

▪� Security

  🔸 The Hacker News - leading news source dedicated to promoting awareness for security experts and hackers.
  🔸 Latest Hacking News - provides the latest hacking news, exploits and vulnerabilities for ethical hackers.
  🔸 Security Newsletter - security news as a weekly digest (email notifications).
  🔸 Google Online Security Blog - the latest news and insights from Google on security and safety on the Internet.
  🔸 Qualys Blog - expert network security guidance and news.
  🔸 DARKReading - connecting the Information Security Community.
  🔸 Darknet - latest hacking tools, hacker news, cybersecurity best practices, ethical hacking & pen-testing.
  🔸 publiclyDisclosed - public disclosure watcher who keeps you up to date about the recently disclosed bugs.
  🔸 Reddit - Hacking - a subreddit dedicated to hacking and hackers.
  🔸 Packet Storm - information security services, news, files, tools, exploits, advisories and whitepapers.
  🔸 Sekurak - about security, penetration tests, vulnerabilities and many others (PL/EN).
  🔸 nf.sec - basic aspects and mechanisms of Linux operating system security (PL).

▪� Other/All-in-one

  🔸 Changelog - is a community of hackers; news & podcasts for developers and hackers.

Other Cheat Sheets  ^[TOC]

Build your own DNS Servers

  🔸 Unbound DNS Tutorial - a validating, recursive, and caching DNS server.
  🔸 Knot Resolver on Fedora - how to get faster and more secure DNS resolution with Knot Resolver on Fedora.
  🔸 DNS-over-HTTPS - tutorial to setup your own DNS-over-HTTPS (DoH) server.
  🔸 DNS-over-TLS - following to your DoH server, setup your DNS-over-TLS (DoT) server.
  🔸 DNS Servers - how (and why) i run my own DNS Servers.

Build your own Certificate Authority

  🔸 OpenSSL Certificate Authority - build your own certificate authority (CA) using the OpenSSL command-line tools.

Build your own System/Virtual Machine

  🔸 os-tutorial - how to create an OS from scratch.
  🔸 Write your Own Virtual Machine - how to write your own virtual machine (VM).
  🔸 x86 Bare Metal Examples - dozens of minimal operating systems to learn x86 system programming.
  🔸 simple-computer - the scott CPU from "But How Do It Know?" by J. Clark Scott.

DNS Servers list (privacy)

IP	URL
84.200.69.80	dns.watch
94.247.43.254	opennic.org
64.6.64.6	verisign.com
89.233.43.71	censurfridns.dk
1.1.1.1	cloudflare.com
94.130.110.185	dnsprivacy.at

TOP Browser extensions

Extension name	Description
IPvFoo	Display the server IP address and HTTPS information across all page elements.
FoxyProxy	Simplifies configuring browsers to access proxy-servers.
HTTPS Everywhere	Automatically use HTTPS security on many sites.
uMatrix	Point & click to forbid/allow any class of requests made by your browser.
uBlock Origin	An efficient blocker: easy on memory and CPU footprint.
Session Buddy	Manage browser tabs and bookmarks with ease.
SuperSorter	Sort bookmarks recursively, delete duplicates, merge folders and more.
Clear Cache	Clear your cache and browsing data.
d3coder	Encoding/Decoding plugin for various types of encoding.
Web Developer	Adds a toolbar button with various web developer tools.
ThreatPinch Lookup	Add threat intelligence hover tool tips.

TOP Burp extensions

Extension name	Description
Autorize	Automatically detects authorization enforcement.
Reflection	An efficient blocker: easy on memory and CPU footprint.
Logger++	Logs requests and responses for all Burp tools in a sortable table.
Bypass WAF	Adds headers useful for bypassing some WAF devices.
JSON Beautifier	Beautifies JSON content in the HTTP message viewer.
JSON Web Tokens	Enables Burp to decode and manipulate JSON web tokens.
CSP Auditor	Displays CSP headers for responses, and passively reports CSP weaknesses.
CSP-Bypass	Passively scans for CSP headers that contain known bypasses.
Hackvertor	Converts data using a tag-based configuration to apply various encoding.
Active Scan++	Extends Burp's active and passive scanning capabilities.
HTML5 Auditor	Scans for usage of risky HTML5 features.
Software Vulnerability Scanner	Software vulnerability scanner based on Vulners.com audit API.

One-liners  ^[TOC]

Table of Contents

• terminal
• mount
• fuser
• lsof
• ps
• top
• vmstat
• iostat
• strace
• kill
• find
• diff
• vimdiff
• tail
• cpulimit
• pwdx
• tr
• chmod
• who
• last
• screen
• script
• du
• inotifywait
• openssl
• secure-delete
• dd
• gpg
• system-other
• curl
• httpie
• ssh
• linux-dev
• tcpdump
• tcpick
• ngrep
• hping3
• nmap
• netcat
• socat
• p0f
• gnutls-cli
• netstat
• rsync
• host
• dig
• certbot
• network-other
• git
• awk
• sed
• grep

Tool: terminal

Reload shell without exit

exec $SHELL -l

Close shell keeping all subprocess running

disown -a && exit

Exit without saving shell history

kill -9 $$
unset HISTFILE && exit

Perform a branching conditional

true && echo success
false || echo failed

Pipe stdout and stderr to separate commands

some_command > >(/bin/cmd_for_stdout) 2> >(/bin/cmd_for_stderr)

Redirect stdout and stderr each to separate files and print both to the screen

(some_command 2>&1 1>&3 | tee errorlog ) 3>&1 1>&2 | tee stdoutlog

List of commands you use most often

history | \
awk '{CMD[$2]++;count++;}END { for (a in CMD)print CMD[a] " " CMD[a]/count*100 "% " a;}' | \
grep -v "./" | \
column -c3 -s " " -t | \
sort -nr | nl |  head -n 20

Sterilize bash history

function sterile() {
    history | awk '$2 != "history" { $1=""; print $0 }' | egrep -vi "\
curl\b+.*(-E|--cert)\b+.*\b*|\
curl\b+.*--pass\b+.*\b*|\
curl\b+.*(-U|--proxy-user).*:.*\b*|\
curl\b+.*(-u|--user).*:.*\b*
.*(-H|--header).*(token|auth.*)\b+.*|\
wget\b+.*--.*password\b+.*\b*|\
http.?://.+:.+@.*\
" > $HOME/histbuff; history -r $HOME/histbuff;
}

export PROMPT_COMMAND="sterile"

Quickly backup a file

cp filename{,.orig}

Empty a file (truncate to 0 size)

>filename

Delete all files in a folder that don't match a certain file extension

rm !(*.foo|*.bar|*.baz)

Pass multi-line string to a file

# cat  >filename ... - overwrite the file
# cat >>filename ... - append to a file
cat > filename << __EOF__
data data data
__EOF__

Edit a file on a remote host using vim

vim scp://user@host//etc/fstab

Create a directory and change into it at the same time

mkd() { mkdir -p "$@" && cd "$@"; }

Convert uppercase files to lowercase files

rename 'y/A-Z/a-z/' *

Print a row of characters across the terminal

printf "%`tput cols`s" | tr ' ' '#'

Show shell history without line numbers

history | cut -c 8-
fc -l -n 1 | sed 's/^\s*//'

Run command(s) after exit session

cat > /etc/profile << __EOF__
_after_logout() {

  username=$(whoami)

  for _pid in $(ps afx | grep sshd | grep "$username" | awk '{print $1}') ; do

    kill -9 $_pid

  done

}
trap _after_logout EXIT
__EOF__

Generate a sequence of numbers

for ((i=1; i<=10; i+=2)) ; do echo $i ; done
# alternative: seq 1 2 10

for ((i=5; i<=10; ++i)) ; do printf '%02d\n' $i ; done
# alternative: seq -w 5 10

for i in {1..10} ; do echo $i ; done

Simple Bash filewatching

unset MAIL; export MAILCHECK=1; export MAILPATH='$FILE_TO_WATCH?$MESSAGE'

---

Tool: mount

Mount a temporary ram partition

mount -t tmpfs tmpfs /mnt -o size=64M

• -t - filesystem type
• -o - mount options

Remount a filesystem as read/write

mount -o remount,rw /

---

Tool: fuser

Show which processes use the files/directories

fuser /var/log/daemon.log
fuser -v /home/supervisor

Kills a process that is locking a file

fuser -ki filename

• -i - interactive option

Kills a process that is locking a file with specific signal

fuser -k -HUP filename

• --list-signals - list available signal names

Show what PID is listening on specific port

fuser -v 53/udp

Show all processes using the named filesystems or block device

fuser -mv /var/www

---

Tool: lsof

Show process that use internet connection at the moment

lsof -P -i -n

Show process that use specific port number

lsof -i tcp:443

Lists all listening ports together with the PID of the associated process

lsof -Pan -i tcp -i udp

List all open ports and their owning executables

lsof -i -P | grep -i "listen"

Show all open ports

lsof -Pnl -i

Show open ports (LISTEN)

lsof -Pni4 | grep LISTEN | column -t

List all files opened by a particular command

lsof -c "process"

View user activity per directory

lsof -u username -a +D /etc

Show 10 largest open files

lsof / | \
awk '{ if($7 > 1048576) print $7/1048576 "MB" " " $9 " " $1 }' | \
sort -n -u | tail | column -t

Show current working directory of a process

lsof -p <PID> | grep cwd

---

Tool: ps

Show a 4-way scrollable process tree with full details

ps awwfux | less -S

Processes per user counter

ps hax -o user | sort | uniq -c | sort -r

Show all processes by name with main header

ps -lfC nginx

---

Tool: find

Find files that have been modified on your system in the past 60 minutes

find / -mmin 60 -type f

Find all files larger than 20M

find / -type f -size +20M

Find duplicate files (based on MD5 hash)

find -type f -exec md5sum '{}' ';' | sort | uniq --all-repeated=separate -w 33

Change permission only for files

cd /var/www/site && find . -type f -exec chmod 766 {} \;
cd /var/www/site && find . -type f -exec chmod 664 {} +

Change permission only for directories

cd /var/www/site && find . -type d -exec chmod g+x {} \;
cd /var/www/site && find . -type d -exec chmod g+rwx {} +

Find files and directories for specific user

find . -user <username> -print

Find files and directories for all without specific user

find . \!-user <username> -print

Delete older files than 60 days

find . -type f -mtime +60 -delete

Recursively remove all empty sub-directories from a directory

find . -depth  -type d  -empty -exec rmdir {} \;

How to find all hard links to a file

find </path/to/dir> -xdev -samefile filename

Recursively find the latest modified files

find . -type f -exec stat --format '%Y :%y %n' "{}" \; | sort -nr | cut -d: -f2- | head

Recursively find/replace of a string with sed

find . -not -path '*/\.git*' -type f -print0 | xargs -0 sed -i 's/foo/bar/g'

Recursively find/replace of a string in directories and file names

find . -depth -name '*test*' -execdir bash -c 'mv -v "$1" "${1//foo/bar}"' _ {} \;

Recursively find suid executables

find / \( -perm -4000 -o -perm -2000 \) -type f -exec ls -la {} \;

---

Tool: top

Use top to monitor only all processes with the specific string

top -p $(pgrep -d , <str>)

• <str> - process containing string (eg. nginx, worker)

---

Tool: vmstat

Show current system utilization (fields in kilobytes)

vmstat 2 20 -t -w

• 2 - number of times with a defined time interval (delay)
• 20 - each execution of the command (count)
• -t - show timestamp
• -w - wide output
• -S M - output of the fields in megabytes instead of kilobytes

Show current system utilization will get refreshed every 5 seconds

vmstat 5 -w

Display report a summary of disk operations

vmstat -D

Display report of event counters and memory stats

vmstat -s

Display report about kernel objects stored in slab layer cache

vmstat -m

Tool: iostat

Show information about the CPU usage, and I/O statistics about all the partitions

iostat 2 10 -t -m

• 2 - number of times with a defined time interval (delay)
• 10 - each execution of the command (count)
• -t - show timestamp
• -m - fields in megabytes (-k - in kilobytes, default)

Show information only about the CPU utilization

iostat 2 10 -t -m -c

Show information only about the disk utilization

iostat 2 10 -t -m -d

Show information only about the LVM utilization

iostat -N

---

Tool: strace

Track with child processes

# 1)
strace -f -p $(pidof glusterfsd)

# 2)
strace -f $(pidof php-fpm | sed 's/\([0-9]*\)/\-p \1/g')

Track process with 30 seconds limit

timeout 30 strace $(< /var/run/zabbix/zabbix_agentd.pid)

Track processes and redirect output to a file

ps auxw | grep '[a]pache' | awk '{print " -p " $2}' | \
xargs strace -o /tmp/strace-apache-proc.out

Track with print time spent in each syscall and limit length of print strings

ps auxw | grep '[i]init_policy' | awk '{print " -p " $2}' | \
xargs strace -f -e trace=network -T -s 10000

Track the open request of a network port

strace -f -e trace=bind nc -l 80

Track the open request of a network port (show TCP/UDP)

strace -f -e trace=network nc -lu 80

---

Tool: kill

Kill a process running on port

kill -9 $(lsof -i :<port> | awk '{l=$2} END {print l}')

---

Tool: diff

Compare two directory trees

diff <(cd directory1 && find | sort) <(cd directory2 && find | sort)

Compare output of two commands

diff <(cat /etc/passwd) <(cut -f2 /etc/passwd)

---

Tool: vimdiff

Highlight the exact differences, based on characters and words

vimdiff file1 file2

Compare two JSON files

vimdiff <(jq -S . A.json) <(jq -S . B.json)

Compare Hex dump

d(){ vimdiff <(f $1) <(f $2);};f(){ hexdump -C $1|cut -d' ' -f3-|tr -s ' ';}; d ~/bin1 ~/bin2

diffchar

Save diffchar @ ~/.vim/plugins

Click F7 to switch between diff modes

Usefull vimdiff commands:

• qa to exit all windows
• :vertical resize 70 to resize window
• set window width Ctrl+W [N columns]+(Shift+)<\>

---

Tool: tail

Annotate tail -f with timestamps

tail -f file | while read ; do echo "$(date +%T.%N) $REPLY" ; done

Analyse an Apache access log for the most common IP addresses

tail -10000 access_log | awk '{print $1}' | sort | uniq -c | sort -n | tail

Analyse web server log and show only 5xx http codes

tail -n 100 -f /path/to/logfile | grep "HTTP/[1-2].[0-1]\" [5]"

---

Tool: tar

System backup with exclude specific directories

cd /
tar -czvpf /mnt/system$(date +%d%m%Y%s).tgz --directory=/ \
--exclude=proc/* --exclude=sys/* --exclude=dev/* --exclude=mnt/* .

System backup with exclude specific directories (pigz)

cd /
tar cvpf /backup/snapshot-$(date +%d%m%Y%s).tgz --directory=/ \
--exclude=proc/* --exclude=sys/* --exclude=dev/* \
--exclude=mnt/* --exclude=tmp/* --use-compress-program=pigz .

---

Tool: dump

System backup to file

dump -y -u -f /backup/system$(date +%d%m%Y%s).lzo /

Restore system from lzo file

cd /
restore -rf /backup/system$(date +%d%m%Y%s).lzo

---

Tool: cpulimit

Limit the cpu usage of a process

cpulimit -p pid -l 50

---

Tool: pwdx

Show current working directory of a process

pwdx <pid>

---

Tool: taskset

Start a command on only one CPU core

taskset -c 0 <command>

---

Tool: tr

Show directories in the PATH, one per line

tr : '\n' <<<$PATH

---

Tool: chmod

Remove executable bit from all files in the current directory

chmod -R -x+X *

Restore permission for /bin/chmod

# 1:
cp /bin/ls chmod.01
cp /bin/chmod chmod.01
./chmod.01 700 file

# 2:
/bin/busybox chmod 0700 /bin/chmod

# 3:
setfacl --set u::rwx,g::---,o::--- /bin/chmod

---

Tool: who

Find last reboot time

who -b

Detect a user sudo-su'd into the current shell

[[ $(who -m | awk '{ print $1 }') == $(whoami) ]] || echo "You are su-ed to $(whoami)"

---

Tool: last

Was the last reboot a panic?

(last -x -f $(ls -1t /var/log/wtmp* | head -2 | tail -1); last -x -f /var/log/wtmp) | \
grep -A1 reboot | head -2 | grep -q shutdown && echo "Expected reboot" || echo "Panic reboot"

---

Tool: screen

Start screen in detached mode

screen -d -m <command>

Attach to an existing screen session

screen -r -d <pid>

---

Tool: script

Record and replay terminal session

### Record session
# 1)
script -t 2>~/session.time -a ~/session.log

# 2)
script --timing=session.time session.log

### Replay session
scriptreplay --timing=session.time session.log

---

Tool: du

Show 20 biggest directories with 'K M G'

du | \
sort -r -n | \
awk '{split("K M G",v); s=1; while($1>1024){$1/=1024; s++} print int($1)" "v[s]"\t"$2}' | \
head -n 20

---

Tool: inotifywait

Init tool everytime a file in a directory is modified

while true ; do inotifywait -r -e MODIFY dir/ && ls dir/ ; done;

---

Tool: openssl

Testing connection to the remote host

echo | openssl s_client -connect google.com:443 -showcerts

Testing connection to the remote host (with SNI support)

echo | openssl s_client -showcerts -servername google.com -connect google.com:443

Testing connection to the remote host with specific ssl version

openssl s_client -tls1_2 -connect google.com:443

Testing connection to the remote host with specific ssl cipher

openssl s_client -cipher 'AES128-SHA' -connect google.com:443

Verify 0-RTT

_host="example.com"

cat > req.in << __EOF__
HEAD / HTTP/1.1
Host: $_host
Connection: close
__EOF__

openssl s_client -connect ${_host}:443 -tls1_3 -sess_out session.pem -ign_eof < req.in
openssl s_client -connect ${_host}:443 -tls1_3 -sess_in session.pem -early_data req.in

Generate private key without passphrase

# _len: 2048, 4096
( _fd="private.key" ; _len="4096" ; \
openssl genrsa -out ${_fd} ${_len} )

Generate private key with passphrase

# _ciph: des3, aes128, aes256
# _len: 2048, 4096
( _ciph="aes128" ; _fd="private.key" ; _len="4096" ; \
openssl genrsa -${_ciph} -out ${_fd} ${_len} )

Remove passphrase from private key

( _fd="private.key" ; _fd_unp="private_unp.key" ; \
openssl rsa -in ${_fd} -out ${_fd_unp} )

Encrypt existing private key with a passphrase

# _ciph: des3, aes128, aes256
( _ciph="aes128" ; _fd="private.key" ; _fd_pass="private_pass.key" ; \
openssl rsa -${_ciph} -in ${_fd} -out ${_fd_pass}

Check private key

( _fd="private.key" ; \
openssl rsa -check -in ${_fd} )

Get public key from private key

( _fd="private.key" ; _fd_pub="public.key" ; \
openssl rsa -pubout -in ${_fd} -out ${_fd_pub} )

Generate private key and CSR

( _fd="private.key" ; _fd_csr="request.csr" ; _len="4096" ; \
openssl req -out ${_fd_csr} -new -newkey rsa:${_len} -nodes -keyout ${_fd} )

Generate CSR

( _fd="private.key" ; _fd_csr="request.csr" ; \
openssl req -out ${_fd_csr} -new -key ${_fd} )

Generate CSR (metadata from existing certificate)

( _fd="private.key" ; _fd_csr="request.csr" ; _fd_crt="cert.crt" ; \
openssl x509 -x509toreq -in ${_fd_crt} -out ${_fd_csr} -signkey ${_fd} )

Generate CSR with -config param

( _fd="private.key" ; _fd_csr="request.csr" ; \
openssl req -new -sha256 -key ${_fd} -out ${_fd_csr} \
-config <(
cat <<-EOF
[req]
default_bits        = 2048
default_md          = sha256
prompt              = no
distinguished_name  = dn
req_extensions      = req_ext

[ dn ]
C   = "<two-letter ISO abbreviation for your country>"
ST  = "<state or province where your organisation is legally located>"
L   = "<city where your organisation is legally located>"
O   = "<legal name of your organisation>"
OU  = "<section of the organisation>"
CN  = "<fully qualified domain name>"

[ req_ext ]
subjectAltName = @alt_names

[ alt_names ]
DNS.1 = <fully qualified domain name>
DNS.2 = <next domain>
DNS.3 = <next domain>
EOF
))

Other values in [ dn ]:

Look at this great explanation: How to create multidomain certificates using config files

countryName            = "DE"                     # C=
stateOrProvinceName    = "Hessen"                 # ST=
localityName           = "Keller"                 # L=
postalCode             = "424242"                 # L/postalcode=
streetAddress          = "Crater 1621"            # L/street=
organizationName       = "apfelboymschule"        # O=
organizationalUnitName = "IT Department"          # OU=
commonName             = "example.com"            # CN=
emailAddress           = "webmaster@example.com"  # CN/emailAddress=

List available EC curves

openssl ecparam -list_curves

Generate ECDSA private key

# _curve: prime256v1, secp521r1, secp384r1
( _fd="private.key" ; _curve="prime256v1" ; \
openssl ecparam -out ${_fd} -name ${_curve} -genkey )

# _curve: X25519
( _fd="private.key" ; _curve="x25519" ; \
openssl genpkey -algorithm ${_curve} -out ${_fd} )

Print ECDSA private and public keys

( _fd="private.key" ; \
openssl ec -in ${_fd} -noout -text )

# For x25519 only extracting public key
( _fd="private.key" ; _fd_pub="public.key" ; \
openssl pkey -in ${_fd} -pubout -out ${_fd_pub} )

Generate private key with CSR (ECC)

# _curve: prime256v1, secp521r1, secp384r1
( _fd="domain.com.key" ; _fd_csr="domain.com.csr" ; _curve="prime256v1" ; \
openssl ecparam -out ${_fd} -name ${_curve} -genkey ; \
openssl req -new -key ${_fd} -out ${_fd_csr} -sha256 )

Generate self-signed certificate

# _len: 2048, 4096
( _fd="domain.key" ; _fd_out="domain.crt" ; _len="4096" ; _days="365" ; \
openssl req -newkey rsa:${_len} -nodes \
-keyout ${_fd} -x509 -days ${_days} -out ${_fd_out} )

Generate self-signed certificate from existing private key

# _len: 2048, 4096
( _fd="domain.key" ; _fd_out="domain.crt" ; _days="365" ; \
openssl req -key ${_fd} -nodes \
-x509 -days ${_days} -out ${_fd_out} )

Generate self-signed certificate from existing private key and csr

# _len: 2048, 4096
( _fd="domain.key" ; _fd_csr="domain.csr" ; _fd_out="domain.crt" ; _days="365" ; \
openssl x509 -signkey ${_fd} -nodes \
-in ${_fd_csr} -req -days ${_days} -out ${_fd_out} )

Generate DH Param key

openssl dhparam -out /etc/nginx/ssl/dhparam_4096.pem 4096

Extract private key from pfx

( _fd_pfx="cert.pfx" ; _fd_key="key.pem" ; \
openssl pkcs12 -in ${_fd_pfx} -nocerts -nodes -out ${_fd_key} )

Extract private key and certs from pfx

( _fd_pfx="cert.pfx" ; _fd_pem="key_certs.pem" ; \
openssl pkcs12 -in ${_fd_pfx} -nodes -out ${_fd_pem} )

Convert DER to PEM

( _fd_der="cert.crt" ; _fd_pem="cert.pem" ; \
openssl x509 -in ${_fd_der} -inform der -outform pem -out ${_fd_pem} )

Convert PEM to DER

( _fd_der="cert.crt" ; _fd_pem="cert.pem" ; \
openssl x509 -in ${_fd_pem} -outform der -out ${_fd_der} )

Verification of the private key

( _fd="private.key" ; \
openssl rsa -noout -text -in ${_fd} )

Verification of the public key

# 1)
( _fd="public.key" ; \
openssl pkey -noout -text -pubin -in ${_fd} )

# 2)
( _fd="private.key" ; \
openssl rsa -inform PEM -noout -in ${_fd} &> /dev/null ; \
if [ $? = 0 ] ; then echo -en "OK\n" ; fi )

Verification of the certificate

( _fd="certificate.crt" ; # format: pem, cer, crt \
openssl x509 -noout -text -in ${_fd} )

Verification of the CSR

( _fd_csr="request.csr" ; \
openssl req -text -noout -in ${_fd_csr} )

Check whether the private key and the certificate match

(openssl rsa -noout -modulus -in private.key | openssl md5 ; \
openssl x509 -noout -modulus -in certificate.crt | openssl md5) | uniq

---

Tool: secure-delete

Secure delete with shred

shred -vfuz -n 10 file
shred --verbose --random-source=/dev/urandom -n 1 /dev/sda

Secure delete with scrub

scrub -p dod /dev/sda
scrub -p dod -r file

Secure delete with badblocks

badblocks -s -w -t random -v /dev/sda
badblocks -c 10240 -s -w -t random -v /dev/sda

Secure delete with secure-delete

srm -vz /tmp/file
sfill -vz /local
sdmem -v
swapoff /dev/sda5 && sswap -vz /dev/sda5

---

Tool: dd

Show dd status every so often

dd <dd_params> status=progress
watch --interval 5 killall -USR1 dd

Redirect output to a file with dd

echo "string" | dd of=filename

---

Tool: gpg

Export public key

gpg --export --armor "<username>" > username.pkey

• --export - export all keys from all keyrings or specific key
• -a|--armor - create ASCII armored output

Encrypt file

gpg -e -r "<username>" dump.sql

• -e|--encrypt - encrypt data
• -r|--recipient - encrypt for specific

Decrypt file

gpg -o dump.sql -d dump.sql.gpg

• -o|--output - use as output file
• -d|--decrypt - decrypt data (default)

Search recipient

gpg --keyserver hkp://keyserver.ubuntu.com --search-keys "<username>"

• --keyserver - set specific key server
• --search-keys - search for keys on a key server

List all of the packets in an encrypted file

gpg --batch --list-packets archive.gpg
gpg2 --batch --list-packets archive.gpg

---

Tool: system-other

Reboot system from init

exec /sbin/init 6

Init system from single user mode

exec /sbin/init

Show current working directory of a process

readlink -f /proc/<PID>/cwd

Show actual pathname of the executed command

readlink -f /proc/<PID>/exe

Tool: curl

curl -Iks https://www.google.com

• -I - show response headers only
• -k - insecure connection when using ssl
• -s - silent mode (not display body)

curl -Iks --location -X GET -A "x-agent" https://www.google.com

• --location - follow redirects
• -X - set method
• -A - set user-agent

curl -Iks --location -X GET -A "x-agent" --proxy http://127.0.0.1:16379 https://www.google.com

• --proxy [socks5://|http://] - set proxy server

curl -o file.pdf -C - https://example.com/Aiju2goo0Ja2.pdf

• -o - write output to file
• -C - resume the transfer

Find your external IP address (external services)

curl ipinfo.io
curl ipinfo.io/ip
curl icanhazip.com
curl ifconfig.me/ip ; echo

Repeat URL request

# URL sequence substitution with a dummy query string:
curl -ks https://example.com/?[1-20]

# With shell 'for' loop:
for i in {1..20} ; do curl -ks https://example.com/ ; done

Check DNS and HTTP trace with headers for specific domains

### Set domains and external dns servers.
_domain_list=(google.com) ; _dns_list=("8.8.8.8" "1.1.1.1")

for _domain in "${_domain_list[@]}" ; do

  printf '=%.0s' {1..48}

  echo

  printf "[\\e[1;32m+\\e[m] resolve: %s\\n" "$_domain"

  for _dns in "${_dns_list[@]}" ; do

    # Resolve domain.
    host "${_domain}" "${_dns}"

    echo

  done

  for _proto in http https ; do

    printf "[\\e[1;32m+\\e[m] trace + headers: %s://%s\\n" "$_proto" "$_domain"

    # Get trace and http headers.
    curl -Iks -A "x-agent" --location "${_proto}://${_domain}"

    echo

  done

done

unset _domain_list _dns_list

---

Tool: httpie

http -p Hh https://www.google.com

• -p - print request and response headers
  • H - request headers
  • B - request body
  • h - response headers
  • b - response body

http -p Hh https://www.google.com --follow --verify no

• -F, --follow - follow redirects
• --verify no - skip SSL verification

http -p Hh https://www.google.com --follow --verify no \
--proxy http:http://127.0.0.1:16379

• --proxy [http:] - set proxy server

Tool: ssh

Escape Sequence

# Supported escape sequences:
~.  - terminate connection (and any multiplexed sessions)
~B  - send a BREAK to the remote system
~C  - open a command line
~R  - Request rekey (SSH protocol 2 only)
~^Z - suspend ssh
~#  - list forwarded connections
~&  - background ssh (when waiting for connections to terminate)
~?  - this message
~~  - send the escape character by typing it twice

Compare a remote file with a local file

ssh user@host cat /path/to/remotefile | diff /path/to/localfile -

SSH connection through host in the middle

ssh -t reachable_host ssh unreachable_host

Run command over SSH on remote host

cat > cmd.txt << __EOF__
cat /etc/hosts
__EOF__

ssh host -l user $(<cmd.txt)

Get public key from private key

ssh-keygen -y -f ~/.ssh/id_rsa

Get all fingerprints

ssh-keygen -l -f .ssh/known_hosts

SSH authentication with user password

ssh -o PreferredAuthentications=password -o PubkeyAuthentication=no user@remote_host

SSH authentication with publickey

ssh -o PreferredAuthentications=publickey -o PubkeyAuthentication=yes -i id_rsa user@remote_host

Simple recording SSH session

function _ssh_sesslog() {

  _sesdir="<path/to/session/logs>"

  mkdir -p "${_sesdir}" && \
  ssh $@ 2>&1 | tee -a "${_sesdir}/$(date +%Y%m%d).log"

}

# Alias:
alias ssh='_ssh_sesslog'

Using Keychain for SSH logins

### Delete all of ssh-agent's keys.
function _scl() {

  /usr/bin/keychain --clear

}

### Add key to keychain.
function _scg() {

  /usr/bin/keychain /path/to/private-key
  source "$HOME/.keychain/$HOSTNAME-sh"

}

SSH login without processing any login scripts

ssh -tt user@host bash

SSH local port forwarding

Example 1:

# Forwarding our local 2250 port to nmap.org:443 from localhost through localhost
host1> ssh -L 2250:nmap.org:443 localhost

# Connect to the service:
host1> curl -Iks --location -X GET https://localhost:2250

Example 2:

# Forwarding our local 9051 port to db.d.x:5432 from localhost through node.d.y
host1> ssh -nNT -L 9051:db.d.x:5432 node.d.y

# Connect to the service:
host1> psql -U db_user -d db_dev -p 9051 -h localhost

• -n - redirects stdin from /dev/null
• -N - do not execute a remote command
• -T - disable pseudo-terminal allocation

SSH remote port forwarding

# Forwarding our local 9051 port to db.d.x:5432 from host2 through node.d.y
host1> ssh -nNT -R 9051:db.d.x:5432 node.d.y

# Connect to the service:
host2> psql -U postgres -d postgres -p 8000 -h localhost

---

Tool: linux-dev

Testing remote connection to port

timeout 1 bash -c "</dev/<proto>/<host>/<port>" >/dev/null 2>&1 ; echo $?

• <proto - set protocol (tcp/udp)
• <host> - set remote host
• <port> - set destination port

Read and write to TCP or UDP sockets with common bash tools

exec 5<>/dev/tcp/<host>/<port>; cat <&5 & cat >&5; exec 5>&-

---

Tool: tcpdump

Filter incoming (on interface) traffic (specific ip:port)

tcpdump -ne -i eth0 -Q in host 192.168.252.1 and port 443

• -n - don't convert addresses (-nn will not resolve hostnames or ports)
• -e - print the link-level headers
• -i [iface|any] - set interface
• -Q|-D [in|out|inout] - choose send/receive direction (-D - for old tcpdump versions)
• host [ip|hostname] - set host, also [host not]
• [and|or] - set logic
• port [1-65535] - set port number, also [port not]

Filter incoming (on interface) traffic (specific ip:port) and write to a file

tcpdump -ne -i eth0 -Q in host 192.168.252.1 and port 443 -c 5 -w tcpdump.pcap

• -c [num] - capture only num number of packets
• -w [filename] - write packets to file, -r [filename] - reading from file

Capture all ICMP packets

tcpdump -nei eth0 icmp

Check protocol used (TCP or UDP) for service

tcpdump -nei eth0 tcp port 22 -vv -X | egrep "TCP|UDP"

Display ASCII text (to parse the output using grep or other)

tcpdump -i eth0 -A -s0 port 443

Grab everything between two keywords

tcpdump -i eth0 port 80 -X | sed -n -e '/username/,/=ldap/ p'

Grab user and pass ever plain http

tcpdump -i eth0  port http -l -A | egrep -i \
'pass=|pwd=|log=|login=|user=|username=|pw=|passw=|passwd=|password=|pass:|user:|username:|password:|login:|pass |user ' \
--color=auto --line-buffered -B20

Extract HTTP User Agent from HTTP request header

tcpdump -ei eth0 -nn -A -s1500 -l | grep "User-Agent:"

Capture only HTTP GET and POST packets

tcpdump -ei eth0 -s 0 -A -vv \
'tcp[((tcp[12:1] & 0xf0) >> 2):4] = 0x47455420' or 'tcp[((tcp[12:1] & 0xf0) >> 2):4] = 0x504f5354'

or simply:

tcpdump -ei eth0 -s 0 -v -n -l | egrep -i "POST /|GET /|Host:"

Rotate capture files

tcpdump -ei eth0 -w /tmp/capture-%H.pcap -G 3600 -C 200

• -G <num> - pcap will be created every <num> seconds
• -C <size> - close the current pcap and open a new one if is larger than <size>

Top hosts by packets

tcpdump -ei enp0s25 -nnn -t -c 200 | cut -f 1,2,3,4 -d '.' | sort | uniq -c | sort -nr | head -n 20

Excludes any RFC 1918 private address

tcpdump -nei eth0 'not (src net (10 or 172.16/12 or 192.168/16) and dst net (10 or 172.16/12 or 192.168/16))'

---

Tool: tcpick

Analyse packets in real-time

while true ; do tcpick -a -C -r dump.pcap ; sleep 2 ; clear ; done

---

Tool: ngrep

ngrep -d eth0 "www.domain.com" port 443

• -d [iface|any] - set interface
• [domain] - set hostname
• port [1-65535] - set port number

ngrep -d eth0 "www.domain.com" src host 10.240.20.2 and port 443

• (host [ip|hostname]) - filter by ip or hostname
• (port [1-65535]) - filter by port number

ngrep -d eth0 -qt -O ngrep.pcap "www.domain.com" port 443

• -q - quiet mode (only payloads)
• -t - added timestamps
• -O [filename] - save output to file, -I [filename] - reading from file

ngrep -d eth0 -qt 'HTTP' 'tcp'

• HTTP - show http headers
• tcp|udp - set protocol
• [src|dst] host [ip|hostname] - set direction for specific node

ngrep -l -q -d eth0 -i "User-Agent: curl*"

• -l - stdout line buffered
• -i - case-insensitive search

---

Tool: hping3

hping3 -V -p 80 -s 5050 <scan_type> www.google.com

• -V|--verbose - verbose mode
• -p|--destport - set destination port
• -s|--baseport - set source port
• <scan_type> - set scan type
  • -F|--fin - set FIN flag, port open if no reply
  • -S|--syn - set SYN flag
  • -P|--push - set PUSH flag
  • -A|--ack - set ACK flag (use when ping is blocked, RST response back if the port is open)
  • -U|--urg - set URG flag
  • -Y|--ymas - set Y unused flag (0x80 - nullscan), port open if no reply
  • -M 0 -UPF - set TCP sequence number and scan type (URG+PUSH+FIN), port open if no reply

hping3 -V -c 1 -1 -C 8 www.google.com

• -c [num] - packet count
• -1 - set ICMP mode
• -C|--icmptype [icmp-num] - set icmp type (default icmp-echo = 8)

hping3 -V -c 1000000 -d 120 -S -w 64 -p 80 --flood --rand-source <remote_host>

• --flood - sent packets as fast as possible (don't show replies)
• --rand-source - random source address mode
• -d --data - data size
• -w|--win - winsize (default 64)

---

Tool: nmap

Ping scans the network

nmap -sP 192.168.0.0/24

Show only open ports

nmap -F --open 192.168.0.0/24

Full TCP port scan using with service version detection

nmap -p 1-65535 -sV -sS -T4 192.168.0.0/24

Nmap scan and pass output to Nikto

nmap -p80,443 192.168.0.0/24 -oG - | nikto.pl -h -

Recon specific ip:service with Nmap NSE scripts stack

# Set variables:
_hosts="192.168.250.10"
_ports="80,443"

# Set Nmap NSE scripts stack:
_nmap_nse_scripts="+dns-brute,\
                   +http-auth-finder,\
                   +http-chrono,\
                   +http-cookie-flags,\
                   +http-cors,\
                   +http-cross-domain-policy,\
                   +http-csrf,\
                   +http-dombased-xss,\
                   +http-enum,\
                   +http-errors,\
                   +http-git,\
                   +http-grep,\
                   +http-internal-ip-disclosure,\
                   +http-jsonp-detection,\
                   +http-malware-host,\
                   +http-methods,\
                   +http-passwd,\
                   +http-phpself-xss,\
                   +http-php-version,\
                   +http-robots.txt,\
                   +http-sitemap-generator,\
                   +http-shellshock,\
                   +http-stored-xss,\
                   +http-title,\
                   +http-unsafe-output-escaping,\
                   +http-useragent-tester,\
                   +http-vhosts,\
                   +http-waf-detect,\
                   +http-waf-fingerprint,\
                   +http-xssed,\
                   +traceroute-geolocation.nse,\
                   +ssl-enum-ciphers,\
                   +whois-domain,\
                   +whois-ip"

# Set Nmap NSE script params:
_nmap_nse_scripts_args="dns-brute.domain=${_hosts},http-cross-domain-policy.domain-lookup=true,"
_nmap_nse_scripts_args+="http-waf-detect.aggro,http-waf-detect.detectBodyChanges,"
_nmap_nse_scripts_args+="http-waf-fingerprint.intensive=1"

# Perform scan:
nmap --script="$_nmap_nse_scripts" --script-args="$_nmap_nse_scripts_args" -p "$_ports" "$_hosts"

---

Tool: netcat

nc -kl 5000

• -l - listen for an incoming connection
• -k - listening after client has disconnected
• >filename.out - save receive data to file (optional)

nc 192.168.0.1 5051 < filename.in

• < filename.in - send data to remote host

nc -vz 10.240.30.3 5000

• -v - verbose output
• -z - scan for listening daemons

nc -vzu 10.240.30.3 1-65535

• -u - scan only udp ports

Transfer data file (archive)

server> nc -l 5000 | tar xzvfp -
client> tar czvfp - /path/to/dir | nc 10.240.30.3 5000

Launch remote shell

server> nc -l 5000 -e /bin/bash
client> nc 10.240.30.3 5000

Simple file server

while true ; do nc -l 5000 | tar -xvf - ; done

Simple minimal HTTP Server

while true ; do nc -l -p 1500 -c 'echo -e "HTTP/1.1 200 OK\n\n $(date)"' ; done

Simple HTTP Server

Restarts web server after each request - remove while condition for only single connection.

cat > index.html << __EOF__
<!doctype html>
    <head>
        <meta charset="utf-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
        <title></title>
        <meta name="description" content="">
        <meta name="viewport" content="width=device-width, initial-scale=1">
    </head>
    <body>

    <p>

      Hello! It's a site.

    </p>

    </body>
</html>
__EOF__

server> while : ; do \
(echo -ne "HTTP/1.1 200 OK\r\nContent-Length: $(wc -c <index.html)\r\n\r\n" ; cat index.html;) | \
nc -l -p 5000 \
; done

• -p - port number

Simple HTTP Proxy (single connection)

#!/usr/bin/env bash

if [[ $# != 2 ]] ; then
  printf "%s\\n" \
         "usage: ./nc-proxy listen-port bk_host:bk_port"
fi

_listen_port="$1"
_bk_host=$(echo "$2" | cut -d ":" -f1)
_bk_port=$(echo "$2" | cut -d ":" -f2)

printf "  lport: %s\\nbk_host: %s\\nbk_port: %s\\n\\n" \
       "$_listen_port" "$_bk_host" "$_bk_port"

_tmp=$(mktemp -d)
_back="$_tmp/pipe.back"
_sent="$_tmp/pipe.sent"
_recv="$_tmp/pipe.recv"

trap 'rm -rf "$_tmp"' EXIT

mkfifo -m 0600 "$_back" "$_sent" "$_recv"

sed "s/^/=> /" <"$_sent" &
sed "s/^/<=  /" <"$_recv" &

nc -l -p "$_listen_port" <"$_back" | \
tee "$_sent" | \
nc "$_bk_host" "$_bk_port" | \
tee "$_recv" >"$_back"

server> chmod +x nc-proxy && ./nc-proxy 8080 192.168.252.10:8000
  lport: 8080
bk_host: 192.168.252.10
bk_port: 8000

client> http -p h 10.240.30.3:8080
HTTP/1.1 200 OK
Accept-Ranges: bytes
Cache-Control: max-age=31536000
Content-Length: 2748
Content-Type: text/html; charset=utf-8
Date: Sun, 01 Jul 2018 20:12:08 GMT
Last-Modified: Sun, 01 Apr 2018 21:53:37 GMT

Create a single-use TCP or UDP proxy

### TCP -> TCP
nc -l -p 2000 -c "nc [ip|hostname] 3000"

### TCP -> UDP
nc -l -p 2000 -c "nc -u [ip|hostname] 3000"

### UDP -> UDP
nc -l -u -p 2000 -c "nc -u [ip|hostname] 3000"

### UDP -> TCP
nc -l -u -p 2000 -c "nc [ip|hostname] 3000"

---

Tool: gnutls-cli

Testing connection to remote host (with SNI support)

gnutls-cli -p 443 google.com

Testing connection to remote host (without SNI support)

gnutls-cli --disable-sni -p 443 google.com

---

Tool: socat

Testing remote connection to port

socat - TCP4:10.240.30.3:22

• - - standard input (STDIO)
• TCP4:<params> - set tcp4 connection with specific params
  • [hostname|ip] - set hostname/ip
  • [1-65535] - set port number

Redirecting TCP-traffic to a UNIX domain socket under Linux

socat TCP-LISTEN:1234,bind=127.0.0.1,reuseaddr,fork,su=nobody,range=127.0.0.0/8 UNIX-CLIENT:/tmp/foo

• TCP-LISTEN:<params> - set tcp listen with specific params
  • [1-65535] - set port number
  • bind=[hostname|ip] - set bind hostname/ip
  • reuseaddr - allows other sockets to bind to an address
  • fork - keeps the parent process attempting to produce more connections
  • su=nobody - set user
  • range=[ip-range] - ip range
• UNIX-CLIENT:<params> - communicates with the specified peer socket
  • filename - define socket

---

Tool: p0f

Set iface in promiscuous mode and dump traffic to the log file

p0f -i enp0s25 -p -d -o /dump/enp0s25.log

• -i - listen on the specified interface
• -p - set interface in promiscuous mode
• -d - fork into background
• -o - output file

---

Tool: netstat

Graph # of connections for each hosts

netstat -an | awk '/ESTABLISHED/ { split($5,ip,":"); if (ip[1] !~ /^$/) print ip[1] }' | \
sort | uniq -c | awk '{ printf("%s\t%s\t",$2,$1) ; for (i = 0; i < $1; i++) {printf("*")}; print "" }'

Monitor open connections for specific port including listen, count and sort it per IP

watch "netstat -plan | grep :443 | awk {'print \$5'} | cut -d: -f 1 | sort | uniq -c | sort -nk 1"

Grab banners from local IPv4 listening ports

netstat -nlt | grep 'tcp ' | grep -Eo "[1-9][0-9]*" | xargs -I {} sh -c "echo "" | nc -v -n -w1 127.0.0.1 {}"

---

Tool: rsync

Rsync remote data as root using sudo

rsync --rsync-path 'sudo rsync' username@hostname:/path/to/dir/ /local/

---

Tool: host

Resolves the domain name (using external dns server)

host google.com 9.9.9.9

Checks the domain administrator (SOA record)

host -t soa google.com 9.9.9.9

---

Tool: dig

Resolves the domain name (short output)

dig google.com +short

Lookup NS record for specific domain

dig @9.9.9.9 google.com NS

Query only answer section

dig google.com +nocomments +noquestion +noauthority +noadditional +nostats

Query ALL DNS Records

dig google.com ANY +noall +answer

DNS Reverse Look-up

dig -x 172.217.16.14 +short

---

Tool: certbot

Generate multidomain certificate

certbot certonly -d example.com -d www.example.com

Generate wildcard certificate

certbot certonly --manual --preferred-challenges=dns -d example.com -d *.example.com

Generate certificate with 4096 bit private key

certbot certonly -d example.com -d www.example.com --rsa-key-size 4096

---

Tool: network-other

Get all subnets for specific AS (Autonomous system)

AS="AS32934"
whois -h whois.radb.net -- "-i origin ${AS}" | \
grep "^route:" | \
cut -d ":" -f2 | \
sed -e 's/^[ \t]//' | \
sort -n -t . -k 1,1 -k 2,2 -k 3,3 -k 4,4 | \
cut -d ":" -f2 | \
sed -e 's/^[ \t]/allow /' | \
sed 's/$/;/' | \
sed 's/allow  */subnet -> /g'

Resolves domain name from dns.google.com with curl and jq

_dname="google.com" ; curl -s "https://dns.google.com/resolve?name=${_dname}&type=A" | jq .

Tool: git

Log alias for a decent view of your repo

# 1)
git log --oneline --decorate --graph --all

# 2)
git log --graph \
--pretty=format:'%Cred%h%Creset -%C(yellow)%d%Creset %s %Cgreen(%cr) %C(bold blue)<%an>%Creset' \
--abbrev-commit

---

Tool: python

Static HTTP web server

# Python 3.x
python3 -m http.server 8000 --bind 127.0.0.1

# Python 2.x
python -m SimpleHTTPServer 8000

Static HTTP web server with SSL support

# Python 3.x
from http.server import HTTPServer, BaseHTTPRequestHandler
import ssl

httpd = HTTPServer(('localhost', 4443), BaseHTTPRequestHandler)

httpd.socket = ssl.wrap_socket (httpd.socket,
        keyfile="path/to/key.pem",
        certfile='path/to/cert.pem', server_side=True)

httpd.serve_forever()

# Python 2.x
import BaseHTTPServer, SimpleHTTPServer
import ssl

httpd = BaseHTTPServer.HTTPServer(('localhost', 4443),
        SimpleHTTPServer.SimpleHTTPRequestHandler)

httpd.socket = ssl.wrap_socket (httpd.socket,
        keyfile="path/tp/key.pem",
        certfile='path/to/cert.pem', server_side=True)

httpd.serve_forever()

Encode base64

python -m base64 -e <<< "sample string"

Decode base64

python -m base64 -d <<< "dGhpcyBpcyBlbmNvZGVkCg=="

Tool: awk

Remove duplicate entries in a file without sorting

awk '!x[$0]++' filename

Print the last column

awk '{print $NF}' filename

Remove empty lines

awk 'NF > 0' filename

# alternative:
awk NF filename

Print multiple columns with separators

awk -F' ' '{print "ip:\t" $2 "\n port:\t" $3' filename

Exclude multiple columns

awk '{$1=$3=""}1' filename

Get the last hour of Apache logs

awk '/'$(date -d "1 hours ago" "+%d\\/%b\\/%Y:%H:%M")'/,/'$(date "+%d\\/%b\\/%Y:%H:%M")'/ { print $0 }' \
/var/log/httpd/access_log

---

Tool: sed

To print a specific line from a file

sed -n 10p /path/to/file

Remove a specific line from a file

sed -i 10d /path/to/file
# alternative (BSD): sed -i'' 10d /path/to/file

Remove a range of lines from a file

sed -i <file> -re '<start>,<end>d'

Replace newline(s) with a space

sed ':a;N;$!ba;s/\n/ /g' /path/to/file

# cross-platform compatible syntax:
sed -e ':a' -e 'N' -e '$!ba' -e 's/\n/ /g' /path/to/file

• :a create a label a
• N append the next line to the pattern space
• $! if not the last line, ba branch (go to) label a
• s substitute, /\n/ regex for new line, / / by a space, /g global match (as many times as it can)

Alternatives:

# perl version (sed-like speed):
perl -p -e 's/\n/ /' /path/to/file

# bash version (slow):
while read line ; do printf "%s" "$line " ; done < file

Delete string +N next lines

sed '/start/,+4d' /path/to/file

---

Tool: grep

Search for a "pattern" inside all files in the current directory

grep -rn "pattern"
grep -RnisI "pattern" *
fgrep "pattern" * -R

Remove blank lines from a file and save output to new file

grep . filename > newfilename

Show only for multiple patterns

grep 'INFO*'\''WARN' filename
grep 'INFO\|WARN' filename
grep -e INFO -e WARN filename
grep -E '(INFO|WARN)' filename
egrep "INFO|WARN" filename

Except multiple patterns

grep -vE '(error|critical|warning)' filename

Show data from file without comments

grep -v ^[[:space:]]*# filename

Show data from file without comments and new lines

egrep -v '#|^$' filename

Show strings with a dash/hyphen

grep -e -- filename
grep -- -- filename
grep "\-\-" filename

Shell functions  ^[TOC]

Table of Contents

• Domain resolve
• Get ASN

Domain resolve

# Dependencies:
#   - curl
#   - jq

function DomainResolve() {

  local _host="$1"

  local _curl_base="curl --request GET"
  local _timeout="15"

  _host_ip=$($_curl_base -ks -m "$_timeout" "https://dns.google.com/resolve?name=${_host}&type=A" | \
  jq '.Answer[0].data' | tr -d "\"" 2>/dev/null)

  if [[ -z "$_host_ip" ]] || [[ "$_host_ip" == "null" ]] ; then

    echo -en "Unsuccessful domain name resolution.\\n"

  else

    echo -en "$_host > $_host_ip\\n"

  fi

}

Example:

shell> DomainResolve nmap.org
nmap.org > 45.33.49.119

shell> DomainResolve nmap.org
Unsuccessful domain name resolution.

Get ASN

# Dependencies:
#   - curl
#   - python

function GetASN() {

  local _ip="$1"

  local _curl_base="curl --request GET"
  local _timeout="15"

  _asn=$($_curl_base -ks -m "$_timeout" "http://ip-api.com/json/${_ip}" | \
  python -c 'import sys, json; print json.load(sys.stdin)["as"]' 2>/dev/null)

  _state=$(echo $?)

  if [[ -z "$_ip" ]] || [[ "$_ip" == "null" ]] || [[ "$_state" -ne 0 ]]; then

    echo -en "Unsuccessful ASN gathering.\\n"

  else

    echo -en "$_ip > $_asn\\n"

  fi

}

Example:

shell> GetASN 1.1.1.1
1.1.1.1 > AS13335 Cloudflare, Inc.

shell> GetASN 0.0.0.0
Unsuccessful ASN gathering.