nim-loader

a very rough work-in-progress adventure into learning nim by cobbling resources together to create a shellcode loader that implements common EDR/AV evasion techniques.

This is a mess and is for research purposes only! Please don't expect it to compile and run without your own modifications.

Instructions

• Replace the byte array in loader.nim with your own x64 shellcode
• Compile the EXE and run it: nim c -d:danger -d:strip --opt:size "loader.nim"
• Probably adjust which process you want to inject into by looking in the .nim files of the injection folder method you're using...

Completed Features

• Direct syscalls dynamically resolved from NTDLL (Thanks @ShitSecure)
• AMSI and ETW patching (Thanks @byt3bl33d3r)
• NTDLL unhooking (Thanks @MrUn1k0d3r)
• CreateRemoteThread injection (Thanks @byt3bl33d3r, @ShitSecure)

WIP Features

• Process Hollowing Technique (Thanks @snovvcrash)
• Shellcode encryption/decryption using [AES in CTR mode](https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Counter_(CTR) (Thanks @snovvcrash)
• Replace all compatible API calls with syscalls
• Add template generator and compiler, cmdline args for shellcode, injection methods, process paths, etc.

Obfuscation

• Consider using denim by @LittleJoeTables for obfuscator-llvm nim compilation support!

References & Inspiration

• OffensiveNim by Marcello Salvati (@byt3bl33d3r)
• NimlineWhispers2 by Alfie Champion (@ajpc500)
• SysWhispers3 by klezVirus (@KlezVirus)
• NimPackt-v1 by Cas van Cooten (@chvancooten)
• unhook_bof.c by Mr. Un1k0d3r (@MrUn1k0d3r)
• NimGetSyscallStub by S3cur3Th1sSh1t (@ShitSecure)
• NimHollow by snovvcrash (@snovvcrash)

Examples