Reversing

Tutorials

tuts4you
binary-auditing [windows]
RE for beginners [PDF]

CTF Reference

trail of bits
ctf write-ups

Challenges

exploit-exercises
overthewire
smashthestack
gera
crackmes
RE for beginners
AdvancedMemoryChallenges [linux]
Kernel vulns [windows]
flare-on malware/reversing challenges
microcorruption CTF
matasano crypto challenges
Math + programming

Resources

wikipedia [x86]
asm reference [x86]
jump reference [x86]
Secure Coding in C and C++
Hacking: Art of Exploitation
Shellcoder's Handbook
Reversing: Secrets of Reverse Engineering

IRC

##re
#corelan
#radare
#droidsec
#cracking4newbies (@ EFNET)
#openrce

Other

captf: 1 | 2
https://github.com/stripe-ctf/stripe-ctf-2.0
https://github.com/isislab/CTF-Challenges
https://github.com/isislab/Hack-Night
https://github.com/isislab/CTF-Challenges