Memory Injection Mastery: How Attackers Live Off the Land and Bypass EDRs
Alright, let’s break it down. The game’s changed. AV and EDR don’t play like they used to. Signature-based detection is ancient history — now it’s all about behavioral analytics, syscall tracing, and memory forensics.
But attackers? We adapt. And we go in-memory.
What is Memory Injection?
Simple version? Instead of dropping malicious files to disk, attackers inject shellcode or executable code directly into the memory space of another process — usually a legit one.
Why?
Because disk-based detection is noisy. Memory? That’s stealth mode if done right.
Classic Injection Techniques
- DLL Injection – Drop a .dll into another process (meh, noisy if not obfuscated)
- Shellcode Injection – Write shellcode into a remote process and execute it
- Process Hollowing – Spawn a legit process (like
svchost.exe), kill the code, inject your own - Thread Hijacking – Suspend a thread, overwrite, resume
- APC Injection – Queue payloads in another process’s execution path
All these have built-in Windows APIs like VirtualAllocEx, WriteProcessMemory, and CreateRemoteThread. That’s “living off the land.”
But EDRs Watch All That Now, Right?
Yep. That’s why the pros don’t just inject — they cloak it.
We’re talking:
- Manual mapping: Load PE files manually in memory (bypasses loader-based detection)
- Direct syscalls: Avoid detection hooks by invoking syscalls directly (no API calls)
- Inline patching: Overwrite EDR hooks in memory
- Unhooking ntdll.dll: Clean system call gateways
- Encrypted payload staging: Decrypt only at runtime, in-memory, with custom decrypters
The Real Art: Evasion & Execution
The most elite attackers pair memory injection with custom loaders written in:
- C/C++ (still solid with obfuscation)
- Nim (small binary size + compiler weirdness)
- Rust (EDR confusion + memory safety)
- Go (EDR hates it due to garbage collection noise)
Throw in sleep obfuscation, sandbox checks, and non-syscall memory execution and you’re in ninja territory.