j5s / inlinewhispers2

Tool for working with Direct System Calls in Cobalt Strike's Beacon Object Files (BOF) via Syswhispers2

InlineWhispers2

Tool for working with Direct System Calls in Cobalt Strike's Beacon Object Files (BOF) via Syswhispers2

Based on https://github.com/outflanknl/InlineWhispers and https://github.com/helpsystems/nanodump work

How do I set this up?

git clone https://github.com/Sh0ckFR/InlineWhispers2 && cd InlineWhispers2
git clone https://github.com/jthuraisamy/SysWhispers2
cd SysWhispers2/ && python3 syswhispers.py --preset all -o syscalls_all && cd ..

How to use syscalls in your Cobalt-Strike BOF?

Import syscalls.c syscalls.h, syscalls-asm.h in your project and include syscalls.c to start to use syscalls

Now you can use all syscalls that you need:

#include <windows.h>
#include <stdio.h>
#include <tlhelp32.h>

#include "beacon.h"

#include "syscalls.c"

int go(char* args, int length) {
	datap  parser;
	BeaconDataParse(&parser, args, length);

	int pid = BeaconDataInt(&parser);

	BeaconPrintf(CALLBACK_OUTPUT, "	- Opening process: %d.", pid);

	HANDLE hProcess = NULL;
	OBJECT_ATTRIBUTES ObjectAttributes;
	InitializeObjectAttributes(&ObjectAttributes, NULL, 0, NULL, NULL);

	CLIENT_ID uPid = { 0 };
	uPid.UniqueProcess = (HANDLE)(DWORD_PTR)pid;
	uPid.UniqueThread = (HANDLE)0;

	NTSTATUS status = NtOpenProcess(&hProcess, PROCESS_ALL_ACCESS, &ObjectAttributes, &uPid);
	if (hProcess == NULL || status != 0) {
		BeaconPrintf(CALLBACK_OUTPUT, "	[ERROR] Failed to get processhandle, status: 0x%lx", status);
		return 0;
	}
	BeaconPrintf(CALLBACK_OUTPUT, "	- Handle: %x", hProcess);

	NtClose(hProcess);

	return 0;
}

Limitations

Actually, you can't use NtCallEnclave, NtGetCachedSigningLevel, NtGetCachedSigningLevel, NtSetCachedSigningLevel, NtCreateSectionEx syscalls

Credits

• @jthuraisamy for Syswhispers2
• @outflanknl for the first version of InlineWhispers
• @helpsystems for the nanodump exemple
• @boku7 for his awesome work and his kindness