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SLAE32 Certification - Papers - Phrozen
Assignment N°2 - Reverse Shell (NASM)
12 Jun 2020
Assignment Goals (SLAE-1530)
1) Create a TCP Reverse Shellcode for Linux x86-32.
2) The port number should be easily configurable.
3) The IP address should be easily configurable.
3) Bonus if getting referenced in exploit-db or shell-storm.
TCP Reverse Shell Principle
In first exercise we learnt how to create our own TCP Bindshell shellcode using few syscalls (socketcall(), dup2() and execve()).
A reverse shell is almost identical to a classic bindshell, this time instead of having a shellcode that listen for new clients, we will create a shellcode that will connect back to a remote server.
Fortunately, on Linux by default, we do not have any restrictions to manage sockets in client mode.
I invite you to read the first paper before this one. Many things are similar between the two shellcodes and we will only point main differences.
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