DripLoader (PoC)

Evasive shellcode loader for bypassing event-based injection detection, without necessarily suppressing event collection. The project is aiming to highlight limitations of event-driven injection identification, and show the need for more advanced memory scanning and smarter local agent software inventories in EDR.

DripLoader evades common EDRs by:

using the most risky APIs possible like NtAllocateVirtualMemory and NtCreateThreadEx
blending in with call arguments to create events that vendors are forced to drop or log&ignore due to volume
avoiding multi-event correlation by introducing delays

What does DripLoader do

Identifies a base address suitable for our payload
Reserves enough AllocationGranularity (64kB) sized, NO_ACCESS memory segments at the base address
Loops over those
- Allocating PageSize (4kB) sized, writable segments
- Writing shellcode
- Reprotecting as RX
Overwrites prologue of one ntdll function in the remote process memory space with a jmp to our base
Drops a thread on that trampoline

I'll explain some of the thinking here: https://blog.redbluepurple.io/offensive-research/bypassing-injection-detection

And so

It's able to fully bypass many EDR injection detections, including Defender ATP.
Bypasses simple thread-centric scanners like Get-InjectedThread. Persisting within a process is another story, and this is up to the payload author.
It is sRDI-compatible, but if your payload creates another local thread you will lose the benefit of thread start address in ntdll.

To test it out of the box

compile/download
XOR your binary shellcode blob file with default key 0x08, name it blob.bin
place both files in the same directory
run it and follow the prompts or ./DripLoader.exe <target_pid> <delay_per_step_ms>

I attached an example MessageBox blob for your pleasure, be aware though it's size is unrealistically small for a payload.

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