nim-shellcode-fluctuation

Encrypt injected shellcode in memory between C2 callbacks to evade EDR memory scanning. This technique uses XOR or RC4 encryption and modifies memory page permissions to hide payloads in RWX regions during sleep intervals on Windows x64 systems.

Shellcode fluctuation works by encrypting injected shellcode in memory during sleep periods and dynamically modifying memory page permissions between RX and RW. This prevents EDR memory scanners from identifying malicious payloads in RWX regions during sleep intervals.

Yes, you can use Nim on Windows x64 to encrypt shellcode and bypass EDR memory scanning. This approach requires the winim library for Windows API calls and the nim-mangle library for code obfuscation, compiling with MSVC or MinGW compilers.

The best way to hide shellcode in RWX memory regions is to encrypt the payload between C2 callbacks and modify memory page permissions to RX or RW during sleep periods. This prevents memory scanners from detecting active shellcode.

Yes, you need the nim-mangle library to obfuscate shellcode encryption in Nim. It is a required dependency for this evasion technique, alongside the winim library for Windows API interactions, to successfully bypass EDR memory scanning.

Injected shellcode gets detected by EDR during sleep periods because it remains unencrypted in RWX memory regions. Memory scanners scan these regions for malicious payloads, so encrypting shellcode between C2 callbacks and modifying page permissions prevents detection.