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https://github.com/xuanxuan0/DripLoader

Evasive shellcode loader for bypassing event-based injection detection (PoC)
https://github.com/xuanxuan0/DripLoader

edr evasion-attacks shellcode shellcode-injector shellcode-loader

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Evasive shellcode loader for bypassing event-based injection detection (PoC)

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# DripLoader (PoC)
![msbuild](https://github.com/xinbailu/DripLoader/actions/workflows/msbuild.yml/badge.svg)

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.

![image](https://user-images.githubusercontent.com/32537788/119597324-13a7fe00-bde1-11eb-987a-38180ad6574b.png)

## 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

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