Master


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


Branch Awesome License

Created by trimstray and contributors

***

» All suggestions are welcome «

## What is it? This list is a collection of various materials that I use every day in my work. It contain a lot of useful information gathered in one piece. This is not a final and full version - I update it on an ongoing basis. ## For whom? It is intended for everyone and anyone - especially for system and network administrators, devops, pentesters or security researchers. ## :ballot_box_with_check: Todo - [ ] Add useful shell functions - [ ] Add one-liners for collection tools (eg. CLI Tools) - [ ] Generate book pdf format ## The Book of Secret Knowledge (Chapters) #### CLI Tools ##### :black_small_square: Shells

  :small_orange_diamond: Oh My ZSH! - the best framework for managing your Zsh configuration.
  :small_orange_diamond: bash-it - framework for using, developing and maintaining shell scripts and custom commands for your daily work.
  :small_orange_diamond: Oh My Fish - the Fishshell framework.

##### :black_small_square: Managers

  :small_orange_diamond: Midnight Commander - visual file manager, licensed under GNU General Public License.
  :small_orange_diamond: screen - full-screen window manager that multiplexes a physical terminal.
  :small_orange_diamond: tmux - terminal multiplexer, lets you switch easily between several programs in one terminal.
  :small_orange_diamond: tmux-cssh - sets a comfortable and easy to use functionality, clustering and synchronizing virtual tmux-sessions.

##### :black_small_square: Network

  :small_orange_diamond: Curl - command line tool and library for transferring data with URLs.
  :small_orange_diamond: HTTPie - a user-friendly HTTP client.
  :small_orange_diamond: wuzz - interactive cli tool for HTTP inspection.
  :small_orange_diamond: httpstat - visualizes curl statistics in a way of beauty and clarity.
  :small_orange_diamond: gnutls-cli - client program to set up a TLS connection to some other computer.
  :small_orange_diamond: nmap - free and open source (license) utility for network discovery and security auditing.
  :small_orange_diamond: hping - command-line oriented TCP/IP packet assembler/analyzer.
  :small_orange_diamond: mtr - functionality of the 'traceroute' and 'ping' programs in a single network diagnostic tool.
  :small_orange_diamond: masscan - the fastest Internet port scanner, spews SYN packets asynchronously.
  :small_orange_diamond: netcat - networking utility which reads and writes data across network connections, using the TCP/IP protocol.
  :small_orange_diamond: tcpdump - powerful command-line packet analyzer.
  :small_orange_diamond: tshark - dump and analyze network traffic (wireshark cli).
  :small_orange_diamond: bmon - monitoring and debugging tool to capture networking related statistics and prepare them visually.
  :small_orange_diamond: fierce - a DNS reconnaissance tool for locating non-contiguous IP space.
  :small_orange_diamond: sublist3r - fast subdomains enumeration tool for penetration testers.
  :small_orange_diamond: amass - tool obtains subdomain names by scraping data sources, crawling web archives and more.
  :small_orange_diamond: namebench - provides personalized DNS server recommendations based on your browsing history.
  :small_orange_diamond: Nemesis - packet manipulation CLI tool; craft and inject packets of several protocols.
  :small_orange_diamond: packetfu - a mid-level packet manipulation library for Ruby.
  :small_orange_diamond: Scapy - packet manipulation library; forge, send, decode, capture packets of a wide number of protocols.
  :small_orange_diamond: bombardier - fast cross-platform HTTP benchmarking tool written in Go.
  :small_orange_diamond: gobench - http/https load testing and benchmarking tool.
  :small_orange_diamond: Nipe - script to make Tor Network your default gateway.
  :small_orange_diamond: iptraf-ng - is a console-based network monitoring program for Linux that displays information about IP traffic.

##### :black_small_square: SSL/Security

  :small_orange_diamond: sslyze - fast and powerful SSL/TLS server scanning library.
  :small_orange_diamond: sslscan - tests SSL/TLS enabled services to discover supported cipher suites.
  :small_orange_diamond: testssl.sh - testing TLS/SSL encryption anywhere on any port.
  :small_orange_diamond: spiped - is a utility for creating symmetrically encrypted and authenticated pipes between socket addresses.

##### :black_small_square: Auditing Tools

  :small_orange_diamond: lynis - battle-tested security tool for systems running Linux, macOS, or Unix-based operating system.
  :small_orange_diamond: LinEnum - scripted Local Linux Enumeration & Privilege Escalation Checks.
  :small_orange_diamond: Rkhunter - scanner tool for Linux systems that scans backdoors, rootkits and local exploits on your systems.

##### :black_small_square: System Diagnostics/Debuggers

  :small_orange_diamond: strace - diagnostic, debugging and instructional userspace utility for Linux.
  :small_orange_diamond: sysdig - system exploration and troubleshooting tool with first class support for containers.
  :small_orange_diamond: glances - cross-platform system monitoring tool written in Python.
  :small_orange_diamond: htop - interactive text-mode process viewer for Unix systems. It aims to be a better 'top'.
  :small_orange_diamond: lsof - displays in its output information about files that are opened by processes.
  :small_orange_diamond: FlameGraph - stack trace visualizer.
  :small_orange_diamond: lsofgraph - small utility to convert Unix lsof output to a graph showing FIFO and UNIX interprocess communication.

##### :black_small_square: Log Analyzers

  :small_orange_diamond: GoAccess - real-time web log analyzer and interactive viewer that runs in a terminal.
  :small_orange_diamond: ngxtop - real-time metrics for nginx server.

##### :black_small_square: Databases

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

##### :black_small_square: Pentesting

  :small_orange_diamond: Metasploit - tool and framework for pentesting system, web and many more, contains a lot a ready to use exploit.
  :small_orange_diamond: Burp Suite - tool for testing Web application security, intercepting proxy to replay, inject, scan and fuzz HTTP requests.
  :small_orange_diamond: OWASP Zed Attack Proxy - intercepting proxy to replay, inject, scan and fuzz HTTP requests.
  :small_orange_diamond: Nikto2 - web server scanner which performs comprehensive tests against web servers for multiple items.
  :small_orange_diamond: sqlmap - tool that automates the process of detecting and exploiting SQL injection flaws.

##### :black_small_square: Other

  :small_orange_diamond: incron - is an inode-based filesystem notification technology.

#### Web Tools ##### :black_small_square: SSL/Security

  :small_orange_diamond: SSL Server Test - free online service performs a deep analysis of the configuration of any SSL web server.
  :small_orange_diamond: SSL Server Test (DEV) - free online service performs a deep analysis of the configuration of any SSL web server.
  :small_orange_diamond: ImmuniWeb® SSLScan - test SSL/TLS (PCI DSS, HIPAA and NIST).
  :small_orange_diamond: urlscan.io - service to scan and analyse websites.
  :small_orange_diamond: Report URI - monitoring security policies like CSP and HPKP.
  :small_orange_diamond: CSP Evaluator - allows developers and security experts to check if a Content Security Policy.
  :small_orange_diamond: Useless CSP - public list about CSP in some big players (might make them care a bit more).
  :small_orange_diamond: Why No HTTPS? - list of the world's top 100 websites by Alexa rank not automatically redirecting insecure requests.
  :small_orange_diamond: cipherli.st - strong ciphers for Apache, Nginx, Lighttpd and more.
  :small_orange_diamond: badssl.com - memorable site for testing clients against bad SSL configs.
  :small_orange_diamond: tlsfun.de - registered for various tests regarding the TLS/SSL protocol.
  :small_orange_diamond: Common CA Database - repository of information about CAs, and their root and intermediate certificates.
  :small_orange_diamond: CERTSTREAM - real-time certificate transparency log update stream.
  :small_orange_diamond: crt.sh - discovers certificates by continually monitoring all of the publicly known CT.

##### :black_small_square: Privacy

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

##### :black_small_square: HTTP Headers

  :small_orange_diamond: Security Headers - analyse the HTTP response headers (with rating system to the results).
  :small_orange_diamond: Observatory by Mozilla - set of tools to analyze your website.
  :small_orange_diamond: Enable CORS - enable cross-origin resource sharing.

##### :black_small_square: DNS

  :small_orange_diamond: ViewDNS - one source for free DNS related tools and information.
  :small_orange_diamond: DNSlytics - online investigation tool.
  :small_orange_diamond: DNS Spy - monitor, validate and verify your DNS configurations.
  :small_orange_diamond: Find subdomains online - find subdomains for security assessment penetration test.
  :small_orange_diamond: DNSdumpster - dns recon & research, find & lookup dns records.
  :small_orange_diamond: DNS Table online - search for DNS records by domain, IP, CIDR, ISP.
  :small_orange_diamond: PTRarchive.com - this site is responsible for the safekeeping of historical reverse DNS records.
  :small_orange_diamond: xip.ip - wildcard DNS for everyone.

##### :black_small_square: Mail

  :small_orange_diamond: MX Toolbox - all of your MX record, DNS, blacklist and SMTP diagnostics in one integrated tool.
  :small_orange_diamond: blacklistalert - checks to see if your domain is on a Real Time Spam Blacklist.
  :small_orange_diamond: MultiRBL - complete IP check for sending Mailservers.

##### :black_small_square: PGP Keyservers

  :small_orange_diamond: SKS OpenPGP Key server - includes a highly-efficient reconciliation algorithm for keeping the keyservers synchronized.

##### :black_small_square: Mass scanners (search engines)

  :small_orange_diamond: Censys - platform that helps information security practitioners discover, monitor, and analyze devices.
  :small_orange_diamond: Shodan - the world's first search engine for Internet-connected devices.
  :small_orange_diamond: Shodan 2000 - if you use Shodan for everyday work, be sure to see it - looks for randomly generated data from Shodan.
  :small_orange_diamond: GreyNoise - mass scanner (such as Shodan and Censys).
  :small_orange_diamond: ZoomEye - search engine for cyberspace that lets the user find specific network components.
  :small_orange_diamond: FOFA - is a cyberspace search engine.
  :small_orange_diamond: onyphe - is a search engine for open-source and cyber threat intelligence data collected.
  :small_orange_diamond: binaryedge - it scan the entire internet space and create real-time threat intelligence streams and reports.
  :small_orange_diamond: hunter - lets you find email addresses in seconds and connect with the people that matter for your business.
  :small_orange_diamond: wigle - is a submission-based catalog of wireless networks. All the networks. Found by Everyone.
  :small_orange_diamond: PublicWWW - find any alphanumeric snippet, signature or keyword in the web pages HTML, JS and CSS code.
  :small_orange_diamond: IntelTechniques - this repository contains hundreds of online search utilities.
  :small_orange_diamond: GhostProject? - search by full email address or username.
  :small_orange_diamond: Buckets by Grayhatwarfar - database with public search for Open Amazon S3 Buckets and their contents.
  :small_orange_diamond: Vigilante.pw - the breached database directory.
  :small_orange_diamond: builtwith - find out what websites are built with.

##### :black_small_square: Net-tools

  :small_orange_diamond: Netcraft - detailed report about the site, helping you to make informed choices about their integrity.
  :small_orange_diamond: RIPE NCC - not-for-profit membership association, a Regional Internet Registry and the secretariat for the RIPE.
  :small_orange_diamond: Robtex - uses various sources to gather public information about IP numbers, domain names, host names, routes etc.
  :small_orange_diamond: Security Trails - APIs for Security Companies, Researchers and Teams.
  :small_orange_diamond: Online Curl - curl test, analyze HTTP Response Headers.
  :small_orange_diamond: Ping.eu - online Ping, Traceroute, DNS lookup, WHOIS and others.
  :small_orange_diamond: Network-Tools - network tools for webmasters, IT technicians & geeks.
  :small_orange_diamond: URL Encode/Decode - tool from above to either encode or decode a string of text.
  :small_orange_diamond: Uncoder - the online translator for search queries on log data.
  :small_orange_diamond: XSS String Encoder - for generating XSS code to check your input validation filters against XSS.
  :small_orange_diamond: RegExr - online tool to learn, build, & test Regular Expressions (RegEx / RegExp).
  :small_orange_diamond: Hardenize - deploy the security standards.
  :small_orange_diamond: VirusTotal - analyze suspicious files and URLs to detect types of malware.

##### :black_small_square: Code parsers/playgrounds

  :small_orange_diamond: ShellCheck - finds bugs in your shell scripts.
  :small_orange_diamond: jsbin - live pastebin for HTML, CSS & JavaScript and more.
  :small_orange_diamond: PHP Sandbox - test your PHP code with this code tester.

##### :black_small_square: Performance

  :small_orange_diamond: GTmetrix - analyze your site’s speed and make it faster.
  :small_orange_diamond: Sucuri loadtimetester - test here the performance of any of your sites from across the globe.

##### :black_small_square: Passwords

  :small_orange_diamond: Random.org - generate random passwords.
  :small_orange_diamond: Gotcha? - list of 1.4 billion accounts circulates around the Internet.
  :small_orange_diamond: have i been pwned? - check if you have an account that has been compromised in a data breach.

##### :black_small_square: CVE

  :small_orange_diamond: CVE Mitre - list of publicly known cybersecurity vulnerabilities.
  :small_orange_diamond: CVE Details - CVE security vulnerability advanced database.

#### Manuals/Howtos/Tutorials ##### :black_small_square: Bash

  :small_orange_diamond: pure-bash-bible - a collection of pure bash alternatives to external processes.
  :small_orange_diamond: The Bash Hackers Wiki - hold documentation of any kind about GNU Bash.
  :small_orange_diamond: Shell & Utilities - describes the commands and utilities offered to application programs by POSIX-conformant systems.

##### :black_small_square: Programming

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

##### :black_small_square: Unix & Network

  :small_orange_diamond: nixCraft - linux and unix tutorials for new and seasoned sysadmin.
  :small_orange_diamond: TecMint - the ideal Linux blog for Sysadmins & Geeks.
  :small_orange_diamond: Omnisecu - Free Networking, System Administration and Security Tutorials.
  :small_orange_diamond: Unix Toolbox - collection of Unix/Linux/BSD commands and tasks which are useful for IT work or for advanced users.

##### :black_small_square: Security

  :small_orange_diamond: OWASP - worldwide not-for-profit charitable organization focused on improving the security of software.
  :small_orange_diamond: OWASP ASVS 3.0.1 - OWASP Application Security Verification Standard Project.
  :small_orange_diamond: OWASP ASVS 3.0.1 Web App - simple web app that helps developers understand the ASVS requirements.
  :small_orange_diamond: Offensive Security - true performance-based penetration testing training for over a decade.
  :small_orange_diamond: Hacking Articles - LRaj Chandel's Security & Hacking Blog.
  :small_orange_diamond: GTFOBins - list of Unix binaries that can be exploited by an attacker to bypass local security restrictions.
  :small_orange_diamond: AWS security tools - make your AWS cloud environment more secure.
  :small_orange_diamond: HTML5 Security Cheatsheet - a collection of HTML5 related XSS attack vectors.
  :small_orange_diamond: PTES - the penetration testing execution standard.
  :small_orange_diamond: ctf-tools - some setup scripts for security research tools.
  :small_orange_diamond: Guifre Ruiz Notes - collection of secuirty, system, network and pentest cheatsheets.
  :small_orange_diamond: Rawsec's CyberSecurity Inventory - an inventory of tools and resources about CyberSecurity.
  :small_orange_diamond: Application Security Wiki - is an initiative to provide all application security related resources at one place.
  :small_orange_diamond: The Illustrated TLS Connection - every byte of a TLS connection explained and reproduced.

##### :black_small_square: Pentesting

  :small_orange_diamond: Brute XSS - master the art of Cross Site Scripting.
  :small_orange_diamond: SQL Injection Cheat Sheet - detailed technical information about the many different variants of the SQL Injection.

##### :black_small_square: Web Apps

  :small_orange_diamond: Mozilla Web Security - help operational teams with creating secure web applications.

##### :black_small_square: Other

  :small_orange_diamond: CTF Series : Vulnerable Machines - the steps below could be followed to find vulnerabilities and exploits.
  :small_orange_diamond: How to start RE/malware analysis? - collection of some hints and useful links for the beginners.
  :small_orange_diamond: LZone Cheat Sheets - all cheat sheets.
  :small_orange_diamond: Dan’s Cheat Sheets’s - massive cheat sheets documentation.
  :small_orange_diamond: The C10K problem - it's time for web servers to handle ten thousand clients simultaneously, don't you think?
  :small_orange_diamond: Bank Grade Security - when companies say they have "Bank Grade Security" they imply that it is a good thing.
  :small_orange_diamond: HTTPS on Stack Overflow - this is the story of a long journey regarding the implementation of SSL.
  :small_orange_diamond: Julia's Drawings - some drawings about programming and unix world, zines about systems & debugging tools.
  :small_orange_diamond: DEF CON Media Server - great stuff from DEFCON 26.
  :small_orange_diamond: BGP Meets Cat - after 3072 hours of manipulating BGP, Job Snijders has succeeded in drawing a Nyancat.
  :small_orange_diamond: HTTPS in the real world - great tutorial explain how HTTPS works in the real world.

#### Blogs

  :small_orange_diamond: Brendan Gregg's Blog - Brendan Gregg is an industry expert in computing performance and cloud computing.
  :small_orange_diamond: Gynvael "GynDream" Coldwind - Gynvael is a IT security engineer at Google.
  :small_orange_diamond: Michał "lcamtuf" Zalewski - "white hat" hacker, computer security expert.
  :small_orange_diamond: Mattias Geniar - developer, Sysadmin, Blogger, Podcaster and Public Speaker.
  :small_orange_diamond: Nick Craver - Software Developer and Systems Administrator for Stack Exchange.
  :small_orange_diamond: Robert Penz - IT security Expert.
  :small_orange_diamond: Scott Helme - Security Researcher, international speaker and founder of securityheaders.com and report-uri.com.
  :small_orange_diamond: Kacper Szurek - Detection Engineer at ESET.
  :small_orange_diamond: Troy Hunt - Microsoft Regional Director and Microsoft Most Valuable Professional for Developer Security.
  :small_orange_diamond: Linux Audit - the Linux security blog about Auditing, Hardening and Compliance by Michael Boelen.
  :small_orange_diamond: Linux Security Expert - trainings, howtos, checklists, security tools and more.
  :small_orange_diamond: The Grymoire - collection of useful incantations for wizards, be you computer wizards, magicians, or whatever.
  :small_orange_diamond: raymii.org - linux/unix sysadmin specializing in building high availability cloud environments.

##### :black_small_square: A piece of history

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

#### Systems/Services ##### :black_small_square: Systems

  :small_orange_diamond: Slackware - the most "Unix-like" Linux distribution.
  :small_orange_diamond: OpenBSD - multi-platform 4.4BSD-based UNIX-like operating system.
  :small_orange_diamond: HardenedBSD - HardenedBSD aims to implement innovative exploit mitigation and security solutions.
  :small_orange_diamond: Kali Linux - Linux distribution used for Penetration Testing, Ethical Hacking and network security assessments.
  :small_orange_diamond: Backbox Linux - penetration test and security assessment oriented Ubuntu-based Linux distribution.

##### :black_small_square: HTTP(s) Services

  :small_orange_diamond: Varnish HTTP Cache - HTTP accelerator designed for content-heavy dynamic web sites.
  :small_orange_diamond: Nginx - open source web and reverse proxy server that is similar to Apache, but very light weight.

##### :black_small_square: Security/hardening

  :small_orange_diamond: Emerald Onion - seattle-based encrypted-transit internet service provider.
  :small_orange_diamond: Unbound - validating, recursive, and caching DNS resolver (with TLS).
  :small_orange_diamond: Knot Resolver - caching full resolver implementation, including both a resolver library and a daemon.
  :small_orange_diamond: Vulnreport - open-source pentesting management and automation platform by Salesforce Product Security.

#### Networks ##### :black_small_square: Tools

  :small_orange_diamond: CapAnalysis - web visual tool to analyze large amounts of captured network traffic (PCAP analyzer).

##### :black_small_square: Labs

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

#### Awesome Lists

  :small_orange_diamond: Awesome Sysadmin - amazingly awesome open source sysadmin resources.
  :small_orange_diamond: Awesome Shell - awesome command-line frameworks, toolkits, guides and gizmos.
  :small_orange_diamond: Awesome Hacking - awesome lists for hackers, pentesters and security researchers.
  :small_orange_diamond: Awesome Hacking Resources - collection of hacking/penetration testing resources to make you better.
  :small_orange_diamond: Hacking Cheat Sheet - author hacking and pentesting notes.
  :small_orange_diamond: Movies for Hackers - list of movies every hacker & cyberpunk must watch.
  :small_orange_diamond: Awesome Pentest - collection of awesome penetration testing resources, tools and other shiny things.
  :small_orange_diamond: Awesome Pcaptools - collection of tools developed by other researchers to process network traces.
  :small_orange_diamond: SecLists - collection of multiple types of lists used during security assessments, collected in one place.
  :small_orange_diamond: Command-line-text-processing - from finding text to search and replace, from sorting to beautifying text and more.
  :small_orange_diamond: Awesome Scalability - best practices in building High Scalability, High Availability, High Stability and more.
  :small_orange_diamond: Awesome Postgres - list of awesome PostgreSQL software, libraries, tools and resources.
  :small_orange_diamond: Free Security eBooks - list of a Free Security and Hacking eBooks.

#### Hacking/Penetration Testing ##### :black_small_square: Useful Resources

  :small_orange_diamond: PayloadsAllTheThings - a list of useful payloads and bypass for Web Application Security and Pentest/CTF.

##### :black_small_square: Bounty programs

  :small_orange_diamond: Bounty Factory - European bug bounty platform based on the legislation and rules in force in European countries.
  :small_orange_diamond: Openbugbounty - allows any security researcher reporting a vulnerability on any website.
  :small_orange_diamond: hackerone - global hacker community to surface the most relevant security issues.
  :small_orange_diamond: bugcrowd - crowdsourced cybersecurity for the enterprise.
  :small_orange_diamond: Crowdshield - crowdsourced Security & Bug Bounty Management.

##### :black_small_square: Web Training Apps (local installation)

  :small_orange_diamond: OWASP-VWAD - comprehensive and well maintained registry of all known vulnerable web applications.
  :small_orange_diamond: Metasploitable 2 - vulnerable web application amongst security researchers.
  :small_orange_diamond: DVWA - PHP/MySQL web application that is damn vulnerable.
  :small_orange_diamond: OWASP Mutillidae II - free, open source, deliberately vulnerable web-application.
  :small_orange_diamond: OWASP Juice Shop Project - the most bug-free vulnerable application in existence.
  :small_orange_diamond: OWASP WebGoat Project - insecure web application maintained by OWASP designed to teach web app security.
  :small_orange_diamond: Security Ninjas - open source application security training program.
  :small_orange_diamond: hackazon - a modern vulnerable web app.
  :small_orange_diamond: dvna - damn vulnerable NodeJS application.
  :small_orange_diamond: Google Gruyere - web application exploits and defenses.
  :small_orange_diamond: Bodhi - is a playground focused on learning the exploitation of client-side web vulnerabilities.

##### :black_small_square: Labs (ethical hacking platforms)

  :small_orange_diamond: Hack The Box - online platform allowing you to test your penetration testing skills.
  :small_orange_diamond: Hacking-Lab - online ethical hacking, computer network and security challenge platform.
  :small_orange_diamond: pwnable.kr - non-commercial wargame site which provides various pwn challenges regarding system exploitation.
  :small_orange_diamond: Silesia Security Lab - high quality security testing services.
  :small_orange_diamond: Practical Pentest Labs - pentest lab, take your Hacking skills to the next level.
  :small_orange_diamond: Root Me - the fast, easy, and affordable way to train your hacking skills.
  :small_orange_diamond: rozwal.to - a great platform to train your pentesting skills.
  :small_orange_diamond: TryHackMe - learning Cyber Security made easy.
  :small_orange_diamond: OverTheWire - can help you to learn and practice security concepts in the form of fun-filled games.

#### Your daily knowledge and news ##### :black_small_square: RSS Readers

  :small_orange_diamond: Feedly - organize, read and share what matters to you.

##### :black_small_square: Security

  :small_orange_diamond: Google Online Security Blog - the latest news and insights from Google on security and safety on the Internet.
  :small_orange_diamond: Qualys Blog - expert network security guidance and news.
  :small_orange_diamond: DARKReading - connecting the Information Security Community.
  :small_orange_diamond: publiclyDisclosed - public disclosure watcher who keeps you up to date about the recently disclosed bugs.
  :small_orange_diamond: 0day.today - exploits market provides you the possibility to buy zero-day exploits and also to sell 0day exploits.
  :small_orange_diamond: Exploit-DB - the exploit database: exploits, shellcode, 0days, remote exploits, local exploits, web Apps and more.
  :small_orange_diamond: sploitus - the exploit and tools database.
  :small_orange_diamond: Packet Storm - information security services, news, files, tools, exploits, aAdvisories and whitepapers.
  :small_orange_diamond: Sekurak - about security, penetration tests, vulnerabilities and many others (PL/EN).
  :small_orange_diamond: nf.sec - basic aspects and mechanisms of Linux operating system securit (PL).

#### Other Cheat Sheets ###### DNS Servers list (privacy) | IP | URL | | :--- | :--- | | **`84.200.69.80`** | [dns.watch](https://dns.watch/) | | **`94.247.43.254`** | [opennic.org](https://www.opennic.org/) | | **`64.6.64.6`** | [verisign.com](https://www.verisign.com/en_US/security-services/public-dns/index.xhtml) | | **`89.233.43.71`** | [censurfridns.dk](https://blog.uncensoreddns.org/) | | **`1.1.1.1`** | [cloudflare.com](https://www.cloudflare.com/dns/) | | **`94.130.110.185`** | [dnsprivacy.at](https://dnsprivacy.at/) | ###### Build your own DNS Servers

  :small_orange_diamond: Unbound DNS Tutorial - a validating, recursive, and caching DNS server.
  :small_orange_diamond: Knot Resolver on Fedora - how to get faster and more secure DNS resolution with Knot Resolver on Fedora.
  :small_orange_diamond: DNS-over-HTTPS - tutorial to setup your own DNS-over-HTTPS (DoH) server.
  :small_orange_diamond: DNS Servers - how (and why) i run my own DNS Servers.
  :small_orange_diamond: DNS Privacy Server - running your own DoT or DoH server this page provides some ideas.

#### One-liners ##### Table of Contents - **[System](#system)** * [terminal](#tool-terminal) * [mount](#tool-mount) * [fuser](#tool-fuser) * [ps](#tool-ps) * [top](#tool-top) * [strace](#tool-strace) * [kill](#tool-kill) * [find](#tool-find) * [diff](#tool-diff) * [tail](#tool-tail) * [cpulimit](#tool-cpulimit) * [pwdx](#tool-pwdx) * [tr](#tool-tr) * [chmod](#tool-chmod) * [who](#tool-who) * [screen](#tool-screen) * [du](#tool-du) * [inotifywait](#tool-inotifywait) * [openssl](#tool-openssl) * [gnutls-cli](#tool-gnutls-cli) * [secure-delete](#tool-secure-delete) * [dd](#tool-dd) - **[HTTP/HTTPS](#http-https)** * [curl](#tool-curl) * [httpie](#tool-httpie) - **[Network](#network)** * [ssh](#tool-ssh) * [linux-dev](#tool-linux-dev) * [tcpdump](#tool-tcpdump) * [tcpick](#tool-tcpick) * [ngrep](#tool-ngrep) * [hping3](#tool-hping3) * [netcat](#tool-netcat) * [socat](#tool-socat) * [lsof](#tool-lsof) * [netstat](#tool-netstat) * [rsync](#tool-rsync) * [host](#tool-host) * [dig](#tool-dig) * [network-other](#tool-network-other) - **[Programming](#programming)** * [awk](#tool-awk) * [sed](#tool-sed) * [grep](#tool-grep) System ##### Tool: [terminal](https://en.wikipedia.org/wiki/Linux_console) ###### Reload shell without exit ```bash exec $SHELL -l ``` ###### Close shell keeping all subprocess running ```bash disown -a && exit ``` ###### Exit without saving shell history ```bash kill -9 $$ unset HISTFILE && exit ``` ###### Perform a branching conditional ```bash true && { echo success;} || { echo failed; } ``` ###### Pipe stdout and stderr to separate commands ```bash 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 ```bash (some_command 2>&1 1>&3 | tee errorlog ) 3>&1 1>&2 | tee stdoutlog ``` ###### List of commands you use most often ```bash history | \ awk '{CMD[$2]++;count++;}END { for (a in CMD)print CMD[a] " " CMD[a]/count*100 "% " a;}' | \ grep -v "./" | \ column -c3 -s " " -t | \ sort -nr | nl | head -n 20 ``` ###### Quickly backup a file ```bash cp filename{,.orig} ``` ###### Empty a file (truncate to 0 size) ```bash >filename ``` ###### Delete all files in a folder that don't match a certain file extension ```bash rm !(*.foo|*.bar|*.baz) ``` ###### Pass multi-line string to a file ```bash # cat >filename ... - overwrite file # cat >>filename ... - append to file cat > filename << __EOF__ data data data __EOF__ ``` ###### Edit a file on a remote host using vim ```bash vim scp://user@host//etc/fstab ``` ###### Create a directory and change into it at the same time ```bash mkd () { mkdir -p "$@" && cd "$@"; } ``` ###### Convert uppercase files to lowercase files ```bash rename 'y/A-Z/a-z/' * ``` ###### Print a row of characters across the terminal ```bash printf "%`tput cols`s" | tr ' ' '#' ``` ###### Show shell history without line numbers ```bash history | cut -c 8- fc -l -n 1 | sed 's/^\s*//' ``` ###### Run command(s) after exit session ```bash cat > /etc/profile << __EOF__ _after_logout() { username=$(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 ```bash 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 ``` ___ ##### Tool: [mount](https://en.wikipedia.org/wiki/Mount_(Unix)) ###### Mount a temporary ram partition ```bash mount -t tmpfs tmpfs /mnt -o size=64M ``` * `-t` - filesystem type * `-o` - mount options ###### Remount a filesystem as read/write ```bash mount -o remount,rw / ``` ___ ##### Tool: [fuser](https://en.wikipedia.org/wiki/Fuser_(Unix)) ###### Kills a process that is locking a file ```bash fuser -k filename ``` ###### Show what PID is listening on specific port ```bash fuser -v 53/udp ``` ___ ##### Tool: [ps](https://en.wikipedia.org/wiki/Ps_(Unix)) ###### Show a 4-way scrollable process tree with full details ```bash ps awwfux | less -S ``` ###### Processes per user counter ```bash ps hax -o user | sort | uniq -c | sort -r ``` ___ ##### Tool: [find](https://en.wikipedia.org/wiki/Find_(Unix)) ###### Find files that have been modified on your system in the past 60 minutes ```bash find / -mmin 60 -type f ``` ###### Find all files larger than 20M ```bash find / -type f -size +20M ``` ###### Find duplicate files (based on MD5 hash) ```bash find -type f -exec md5sum '{}' ';' | sort | uniq --all-repeated=separate -w 33 ``` ###### Change permission only for files ```bash 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 ```bash 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 ```bash find . -user -print ``` ###### Find files and directories for all without specific user ```bash find . \!-user -print ``` ###### Delete older files than 60 days ```bash find . -type f -mtime +60 -delete ``` ###### Recursively remove all empty sub-directories from a directory ```bash find . -depth -type d -empty -exec rmdir {} \; ``` ###### How to find all hard links to a file ```bash find -xdev -samefile filename ``` ###### Recursively find the latest modified files ```bash find . -type f -exec stat --format '%Y :%y %n' "{}" \; | sort -nr | cut -d: -f2- | head ``` ___ ##### Tool: [top](https://en.wikipedia.org/wiki/Top_(software)) ###### Use top to monitor only all processes with the specific string ```bash top -p $(pgrep -d , ) ``` * `` - process containing str (eg. nginx, worker) ___ ##### Tool: [strace](https://en.wikipedia.org/wiki/Strace) ###### Track the open request of a network port ```bash strace -f -e trace=bind nc -l 80 ``` ###### Track the open request of a network port (show TCP/UDP) ```bash strace -f -e trace=network nc -lu 80 ``` ___ ##### Tool: [kill](https://en.wikipedia.org/wiki/Kill_(command)) ###### Kill a process running on port ```bash kill -9 $(lsof -i : | awk '{l=$2} END {print l}') ``` ___ ##### Tool: [diff](https://en.wikipedia.org/wiki/Diff) ###### Compare two directory trees ```bash diff <(cd directory1 && find | sort) <(cd directory2 && find | sort) ``` ___ ##### Tool: [tail](https://en.wikipedia.org/wiki/Tail_(Unix)) ###### Annotate tail -f with timestamps ```bash tail -f file | while read ; do echo "$(date +%T.%N) $REPLY" ; done ``` ###### Analyse an Apache access log for the most common IP addresses ```bash tail -10000 access_log | awk '{print $1}' | sort | uniq -c | sort -n | tail ``` ###### Analyse web server log and show only 5xx http codes ```bash tail -n 100 -f /path/to/logfile | grep "HTTP/[1-2].[0-1]\" [5]" ``` ___ ##### Tool: [tar](https://en.wikipedia.org/wiki/Tar_(computing)) ###### System backup with exclude specific directories ```bash cd / tar -czvpf /mnt/system$(date +%d%m%Y%s).tgz --directory=/ \ --exclude=proc/* --exclude=sys/* --exclude=dev/* --exclude=mnt/* . ``` ###### System backup with exclude specific directories (pigz) ```bash cd / tar cvpf /backup/snapshot-$(date +%d%m%Y%s).tgz --directory=/ \ --exclude=proc/* --exclude=sys/* --exclude=dev/* \ --exclude=mnt/* --exclude=tmp/* --use-compress-program=pigz . ``` ___ ##### Tool: [dump](https://en.wikipedia.org/wiki/Dump_(program)) ###### System backup to file ```bash dump -y -u -f /backup/system$(date +%d%m%Y%s).lzo / ``` ###### Restore system from lzo file ```bash cd / restore -rf /backup/system$(date +%d%m%Y%s).lzo ``` ___ ##### Tool: [cpulimit](http://cpulimit.sourceforge.net/) ###### Limit the cpu usage of a process ```bash cpulimit -p pid -l 50 ``` ___ ##### Tool: [pwdx](https://www.cyberciti.biz/faq/unix-linux-pwdx-command-examples-usage-syntax/) ###### Show current working directory of a process ```bash pwdx ``` ___ ##### Tool: [taskset](https://www.cyberciti.biz/faq/taskset-cpu-affinity-command/) ###### Start a command on only one CPU core ```bash taskset -c 0 ``` ___ ##### Tool: [tr](https://en.wikipedia.org/wiki/Tr_(Unix)) ###### Show directories in the PATH, one per line ```bash tr : '\n' <<<$PATH ``` ___ ##### Tool: [chmod](https://en.wikipedia.org/wiki/Chmod) ###### Remove executable bit from all files in the current directory ```bash chmod -R -x+X * ``` ###### Restore permission for /bin/chmod ```bash # 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](https://en.wikipedia.org/wiki/Who_(Unix)) ###### Find last reboot time ```bash who -b ``` ___ ##### Tool: [screen](https://en.wikipedia.org/wiki/GNU_Screen) ###### Start screen in detached mode ```bash screen -d -m [] ``` ___ ##### Tool: [du](https://en.wikipedia.org/wiki/GNU_Screen) ###### Show 20 biggest directories with 'K M G' ```bash du | \ sort -r -n | \ awk '{split("K M G",v); s=1; while($1>1024){$1/=1024; s++} print int($1)" "v[s]"\t"$2}' | \ head -n 20 ``` ___ ##### Tool: [inotifywait](https://en.wikipedia.org/wiki/GNU_Screen) ###### Init tool everytime a file in a directory is modified ```bash while true ; do inotifywait -r -e MODIFY dir/ && ls dir/ ; done; ``` ___ ##### Tool: [openssl](https://www.openssl.org/) ###### Testing connection to remote host ```bash echo | openssl s_client -connect google.com:443 -showcerts ``` ###### Testing connection to remote host (with SNI support) ```bash echo | openssl s_client -showcerts -servername google.com -connect google.com:443 ``` ###### Testing connection to remote host with specific ssl version ```bash openssl s_client -tls1_2 -connect google.com:443 ``` ###### Testing connection to remote host with specific ssl cipher ```bash openssl s_client -cipher 'AES128-SHA' -connect google.com:443 ``` ###### Generate private key ```bash # _ciph: des3, aes ( _ciph="des3" ; _fd="private.key" ; _len="2048" ; \ openssl genrsa -${_ciph} -out ${_fd} ${_len} ) ``` ###### Remove password from private key ```bash ( _fd="private.key" ; _fd_unp="private_unp.key" ; \ openssl rsa -in ${_fd} -out ${_fd_unp} ) ``` ###### Get public key from private key ```bash ( _fd="private.key" ; _fd_pub="public.key" ; \ openssl rsa -pubout -in ${_fd} -out ${_fd_pub} ) ``` ###### Generate private key + csr ```bash ( _fd="private.key" ; _fd_csr="request.csr" ; _len="2048" ; \ openssl req -out ${_fd_csr} -new -newkey rsa:${_len} -nodes -keyout ${_fd} ) ``` ###### Generate csr ```bash ( _fd="private.key" ; _fd_csr="request.csr" ; \ openssl req -out ${_fd_csr} -new -key ${_fd} ) ``` ###### Generate csr (metadata from exist certificate) ```bash ( _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 ```bash ( _fd="private.key" ; _fd_csr="request.csr" ; \ openssl req -new -sha256 -key ${_fd} -out ${_fd_csr} \ -config <( cat <<-EOF [req] default_bits = 2048 prompt = no default_md = sha256 req_extensions = req_ext distinguished_name = dn [ dn ] C= ST= L= O= OU=
CN= [ req_ext ] subjectAltName = @alt_names [ alt_names ] DNS.1 = DNS.2 = DNS.3 = EOF )) ``` ###### Convert DER to PEM ```bash ( _fd_der="cert.crt" ; _fd_pem="cert.pem" ; \ openssl x509 -in ${_fd_der} -inform der -outform pem -out ${_fd_pem} ) ``` ###### Convert PEM to DER ```bash ( _fd_der="cert.crt" ; _fd_pem="cert.pem" ; \ openssl x509 -in ${_fd_pem} -outform der -out ${_fd_der} ) ``` ###### Checking whether the private key and the certificate match ```bash (openssl rsa -noout -modulus -in private.key | openssl md5 ; openssl x509 -noout -modulus -in certificate.crt | openssl md5) | uniq ``` ___ ##### Tool: [gnutls-cli](https://gnutls.org/manual/html_node/gnutls_002dcli-Invocation.html) ###### Testing connection to remote host (with SNI support) ```bash gnutls-cli -p 443 google.com ``` ###### Testing connection to remote host (without SNI support) ```bash gnutls-cli --disable-sni -p 443 google.com ``` ___ ##### Tool: [secure-delete](https://wiki.archlinux.org/index.php/Securely_wipe_disk) ###### Secure delete with shred ```bash shred -vfuz -n 10 file shred --verbose --random-source=/dev/urandom -n 1 /dev/sda ``` ###### Secure delete with scrub ```bash scrub -p dod /dev/sda scrub -p dod -r file ``` ###### Secure delete with badblocks ```bash badblocks -s -w -t random -v /dev/sda badblocks -c 10240 -s -w -t random -v /dev/sda ``` ###### Secure delete with secure-delete ```bash srm -vz /tmp/file sfill -vz /local sdmem -v swapoff /dev/sda5 && sswap -vz /dev/sda5 ``` ___ ##### Tool: [dd](https://en.wikipedia.org/wiki/Dd_(Unix)) ###### Show dd status every so often ```bash dd status=progress watch --interval 5 killall -USR1 dd ``` ###### Redirect output to a file with dd ```bash echo "string" | dd of=filename ``` HTTP/HTTPS ##### Tool: [curl](https://curl.haxx.se) ```bash curl -Iks https://www.google.com ``` * `-I` - show response headers only * `-k` - insecure connection when using ssl * `-s` - silent mode (not display body) ```bash curl -Iks --location -X GET -A "x-agent" https://www.google.com ``` * `--location` - follow redirects * `-X` - set method * `-A` - set user-agent ```bash 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 ###### Check DNS and HTTP trace with headers for specific domains ```bash ### 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](https://httpie.org/) ```bash 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 ```bash http -p Hh --follow --max-redirects 5 --verify no https://www.google.com ``` * `-F, --follow` - follow redirects * `--max-redirects N` - maximum for `--follow` * `--verify no` - skip SSL verification ```bash http -p Hh --follow --max-redirects 5 --verify no --proxy http:http://127.0.0.1:16379 https://www.google.com ``` * `--proxy [http:]` - set proxy server Network ##### Tool: [ssh](https://www.openssh.com/) ###### Compare a remote file with a local file ```bash ssh user@host cat /path/to/remotefile | diff /path/to/localfile - ``` ###### SSH connection through host in the middle ```bash ssh -t reachable_host ssh unreachable_host ``` ###### Run command over ssh on remote host ```bash cat > cmd.txt << __EOF__ cat /etc/hosts __EOF__ ssh host -l user $(&1 | tee -a "${_sesdir}/$(date +%Y%m%d).log" } # Alias: alias ssh='_ssh_sesslog' ``` ###### Using Keychain for SSH logins ```bash ### Delete all of ssh-agent's keys. function _scl() { /usr/bin/keychain --clear } ### Add key to keychain. function _scg() { /usr/bin/keychain /path/to/private-key source "$HOME/.keychain/$HOSTNAME-sh" } ``` ___ ##### Tool: [linux-dev](https://www.tldp.org/LDP/abs/html/devref1.html) ###### Testing remote connection to port ```bash timeout 1 bash -c "//" >/dev/null 2>&1 ; echo $? ``` * `` - set remote host * `` - set destination port ###### Read and write to TCP or UDP sockets with common bash tools ```bash exec 5<>/dev/tcp//; cat <&5 & cat >&5; exec 5>&- ``` ___ ##### Tool: [tcpdump](http://www.tcpdump.org/) ```bash tcpdump -ne -i eth0 -Q in host 192.168.252.1 and port 443 ``` * `-n` - don't convert addresses * `-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]` ```bash 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 ___ ##### Tool: [tcpick](http://tcpick.sourceforge.net/) ###### Analyse packets in real-time ```bash while true ; do tcpick -a -C -r dump.pcap ; sleep 2 ; clear ; done ``` ___ ##### Tool: [ngrep](http://ngrep.sourceforge.net/usage.html) ```bash ngrep -d eth0 "www.google.com" port 443 ``` * `-d [iface|any]` - set interface * `[domain]` - set hostname * `port [1-65535]` - set port number ```bash ngrep -d eth0 "www.google.com" (host 10.240.20.2) and (port 443) ``` * `(host [ip|hostname])` - filter by ip or hostname * `(port [1-65535])` - filter by port number ```bash ngrep -d eth0 -qt -O ngrep.pcap "www.google.com" port 443 ``` * `-q` - quiet mode (only payloads) * `-t` - added timestamps * `-O [filename]` - save output to file, `-I [filename]` - reading from file ```bash ngrep -d eth0 -qt 'HTTP' 'tcp' ``` * `HTTP` - show http headers * `tcp|udp` - set protocol * `[src|dst] host [ip|hostname]` - set direction for specific node ```bash ngrep -l -q -d eth0 -i "User-Agent: curl*" ``` * `-l` - stdout line buffered * `-i` - case-insensitive search ___ ##### Tool: [hping3](http://www.hping.org/) ```bash hping3 -V -p 80 -s 5050 www.google.com ``` * `-V|--verbose` - verbose mode * `-p|--destport` - set destination port * `-s|--baseport` - set source port * `` - 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 ```bash 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) ```bash hping3 -V -c 1000000 -d 120 -S -w 64 -p 80 --flood --rand-source ``` * `--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: [netcat](http://netcat.sourceforge.net/) ```bash nc -kl 5000 ``` * `-l` - listen for an incoming connection * `-k` - listening after client has disconnected * `>filename.out` - save receive data to file (optional) ```bash nc 192.168.0.1 5051 < filename.in ``` * `< filename.in` - send data to remote host ```bash nc -vz 10.240.30.3 5000 ``` * `-v` - verbose output * `-z` - scan for listening daemons ```bash nc -vzu 10.240.30.3 1-65535 ``` * `-u` - scan only udp ports ###### Transfer data file (archive) ```bash server> nc -l 5000 | tar xzvfp - client> tar czvfp - /path/to/dir | nc 10.240.30.3 5000 ``` ###### Launch remote shell ```bash server> nc -l 5000 -e /bin/bash client> nc 10.240.30.3 5000 ``` ###### Simple file server ```bash while true ; do nc -l 5000 | tar -xvf - ; done ``` ###### Simple minimal HTTP Server ```bash 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. ```bash cat > index.html << __EOF__

Hello! It's a site.

__EOF__ ``` ```bash server> while : ; do \ (echo -ne "HTTP/1.1 200 OK\r\nContent-Length: $(wc -c /" <"$_sent" & sed "s/^/<= /" <"$_recv" & nc -l -p "$_listen_port" <"$_back" | \ tee "$_sent" | \ nc "$_bk_host" "$_bk_port" | \ tee "$_recv" >"$_back" ``` ```bash 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 ```bash ### 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: [socat](http://www.dest-unreach.org/socat/doc/socat.html/) ###### Testing remote connection to port ```bash socat - TCP4:10.240.30.3:22 ``` * `-` - standard input (STDIO) * `TCP4:` - 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 ```bash 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:` - 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:` - communicates with the specified peer socket * `filename` - define socket ___ ##### Tool: [lsof](https://en.wikipedia.org/wiki/Lsof) ###### Show process that use internet connection at the moment ```bash lsof -P -i -n ``` ###### Show process that use specific port number ```bash lsof -i tcp:443 ``` ###### Lists all listening ports together with the PID of the associated process ```bash lsof -Pan -i tcp -i udp ``` ###### List all open ports and their owning executables ```bash lsof -i -P | grep -i "listen" ``` ###### Show all open ports ```bash lsof -Pnl -i ``` ###### Show open ports (LISTEN) ```bash lsof -Pni4 | grep LISTEN | column -t ``` ###### List all files opened by a particular command ```bash lsof -c "process" ``` ###### View user activity per directory ```bash lsof -u username -a +D /etc ``` ###### Show 10 Largest Open Files ```bash lsof / | \ awk '{ if($7 > 1048576) print $7/1048576 "MB" " " $9 " " $1 }' | \ sort -n -u | tail | column -t ``` ___ ##### Tool: [netstat](https://en.wikipedia.org/wiki/Netstat) ###### Graph # of connections for each hosts ```bash netstat -an | \ grep ESTABLISHED | \ awk '{print $5}' | \ awk -F: '{print $1}' | \ grep -v -e '^[[:space:]]*$' | \ 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 ```bash watch "netstat -plan | grep :443 | awk {'print \$5'} | cut -d: -f 1 | sort | uniq -c | sort -nk 1" ``` ___ ##### Tool: [rsync](https://en.wikipedia.org/wiki/Rsync) ###### Rsync remote data as root using sudo ```bash rsync --rsync-path 'sudo rsync' username@hostname:/path/to/dir/ /local/ ``` ___ ##### Tool: [host](https://en.wikipedia.org/wiki/Host_(Unix)) ###### Resolves the domain name (using external dns server) ```bash host google.com 9.9.9.9 ``` ###### Checks the domain administrator (SOA record) ```bash host -t soa google.com 9.9.9.9 ``` ___ ##### Tool: [dig](https://en.wikipedia.org/wiki/Dig_(command)) ###### Resolves the domain name (short output) ```bash dig google.com +short ``` ###### Lookup NS record for specific domain ```bash dig @9.9.9.9 google.com NS ``` ###### Query only answer section ```bash dig google.com +nocomments +noquestion +noauthority +noadditional +nostats ``` ###### Query ALL DNS Records ```bash dig google.com ANY +noall +answer ``` ###### DNS Reverse Look-up ```bash dig -x 172.217.16.14 +short ``` ___ ##### Tool: [network-other](https://github.com/trimstray/the-book-of-secret-knowledge#tool-network-other) ###### Get all subnets for specific AS (Autonomous system) ```bash 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 ```bash _dname="google.com" ; curl -s "https://dns.google.com/resolve?name=${_dname}&type=A" | jq . ``` Programming ##### Tool: [awk](http://www.grymoire.com/Unix/Awk.html) ###### Remove duplicate entries in a file without sorting ```bash awk '!x[$0]++' filename ``` ###### Exclude multiple columns using AWK ```bash awk '{$1=$3=""}1' filename ``` ___ ##### Tool: [sed](http://www.grymoire.com/Unix/Sed.html) ###### To print a specific line from a file ```bash sed -n 10p /path/to/file ``` ###### Remove a specific line from a file ```bash sed -i 10d /path/to/file # alternative (BSD): sed -i'' 10d /path/to/file ``` ###### Remove a range of lines from a file ```bash sed -i -re ',d' ``` ___ ##### Tool: [grep](http://www.grymoire.com/Unix/Grep.html) ###### Search for a "pattern" inside all files in the current directory ```bash grep -rn "pattern" grep -RnisI "pattern" * fgrep "pattern" * -R ``` ###### Remove blank lines from a file and save output to new file ```bash grep . filename > newfilename ``` ###### Except multiple patterns ```bash grep -vE '(error|critical|warning)' filename ``` ###### Show data from file without comments ```bash grep -v ^[[:space:]]*# filename ``` ###### Show data from file without comments and new lines ```bash egrep -v '#|^$' filename ```