Snow sbmlabs.com

A Whitespace Steganography Tool.

Root-Me root-me.org

Hacking and Information Security learning platform.

Ringzer0Team ringzer0team.com

Ringzer0 Team Online CTF.

Xocopy reverse.lostrealm.com

Program that can copy executables with execute, but no read permission.

Detox relentless-coding.org

A Javascript malware analysis tool.

Reddit Security CTF reddit.com

Reddit CTF category.

QuipQuip quipqiup.com

An online tool for breaking substitution ciphers or vigenere ciphers (without key).

Pwnable.xyz pwnable.xyz

Binary Exploitation Wargame.

Pwnable.tw pwnable.tw

Binary wargame.

PWN Challenge pwn.eonew.cn

Binary Exploitation Wargame.

Turbo Intruder portswigger.net

Burp Suite extension for sending large numbers of HTTP requests

Pentoo pentoo.ch

Based on Gentoo.

Parrot Security OS parrotsec.org

Based on Debian.

Kali Linux CTF Blueprints packtpub.com

Online book on building, testing, and customizing your own Capture the Flag challenges.

Pngtools packages.debian.org

For various analysis related to PNGs.

OWASP ZAP owasp.org

Intercepting proxy to replay, debug, and fuzz HTTP requests and responses

Over The Wire overthewire.org

Wargame maintained by OvertheWire Community.

Ophcrack ophcrack.sourceforge.net

Windows password cracker based on rainbow tables.

Steganabara openhub.net

Tool for stegano analysis written in Java.

CFF Explorer ntcore.com

PE Editor.

ResourcesExtract nirsoft.net

Extract various filetypes from exes.

OfflineRegistryView nirsoft.net

Simple tool for Windows that allows you to read offline Registry files from external drive and view the desired Registry key in .reg file format.

Metasploit metasploit.com

Penetration testing software.

Exif manpages.ubuntu.com

Shows EXIF information in JPEG files.

PDF Streams Inflater malzilla.sourceforge.net

Find and extract zlib files compressed in PDF files.

Magnet AXIOM magnetforensics.com

Artifact-centric DFIR tool.

Fsck.ext4 linux.die.net

Used to fix corrupt filesystems.

Stegbreak linux.die.net

Launches brute-force dictionary attacks on JPG image.

Exiftool linux.die.net

Read and write meta information in files.

Monit linoxide.com

A linux tool to check a host on the network (and other non-network activities).

Pngcheck libpng.org

Verifies the integrity of PNG and dump all of the chunk-level information in human-readable form.

Kroll Artifact Parser and Extractor (KAPE) learn.duffandphelps.com

Triage program.

Fedora Security Lab labs.fedoraproject.org

Based on Fedora.

Revelo kahusecurity.com

Analyze obfuscated Javascript code.

Registry Dumper kahusecurity.com

Dump your registry.

IO io.netgarage.org

Wargame for binary challenges.

Image Steganography Online incoherency.co.uk

This is a client-side Javascript tool to steganographically hide images inside the lower "bits" of other images

Convert imagemagick.org

Convert images b/w formats and apply filters.

ApkTool ibotpeaches.github.io

Android Decompiler.

Intro. to CTF Course hoppersroppers.org

A free course that teaches beginners the basics of forensics, crypto, and web-ex.

Hone Your Ninja Skills honeyourskills.ninja

Web challenges starting from basic ones.

SANS HHC holidayhackchallenge.com

Challenges with a holiday theme released annually and maintained by SANS.

Hashcat hashcat.net

Password Cracker

BinUtils gnu.org

Collection of binary tools.

Metasploit JavaScript Obfuscator github.com

VirusBay beta.virusbay.io

badips.com badips.com

Anonymouse.org anonymouse.org

Practical Malware Analysis amzn.com

The IDA Pro Book amzn.com