Add signatures for unbacked memory activities

[kevross33]

This file implements multiple signatures to detect suspicious activities related to unbacked memory, including DLL loading, token manipulation, registry modifications, network connections, named pipe creation, VEH registration, and process creation.

Some of these are still not fully tested but I don't think they should not work as the ones I have found work fine and they are all implemented with similar logic.

Kazuar (Turla APT backdoor) 1749c96cc1a4beb9ad4d6e037e40902fac31042fa40152f1d3794f49ed1a2b5c

LUMMA 47b04598800c3231e8dd3eae7d187a42b131f851584403be28f1f4364cf523fa

Dridexv4 17afaf60c24ec98039d4273f24888fd457b4aede1e11871e56ed7149ff504fea

Pikabot ca5fb5814ec62c8f04936740aabe2664b3c7d036203afbd8425cd67cf1f4b79d

[gemini-code-assist]

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request introduces a new Python module containing a suite of Cuckoo Sandbox signatures. These signatures are designed to enhance the detection capabilities for advanced evasion techniques by identifying various suspicious activities, such as DLL loading, token manipulation, registry modifications, network connections, named pipe creation, VEH registration, and process creation, specifically when these actions originate from dynamically allocated, unbacked memory regions. This helps in uncovering fileless malware and other stealthy threats.

Highlights

• Unbacked Library Load Detection: Added a signature to detect when a new DLL is loaded from a caller address originating from dynamically allocated (unbacked) memory.
• Unbacked Token Manipulation Detection: Implemented a signature to identify attempts to open, duplicate, or impersonate access tokens by threads executing in unbacked memory.
• Unbacked Registry Persistence Detection: Introduced a signature to flag modifications to the Windows registry originating from threads in unbacked memory.
• Unbacked Network Connection Detection: Added a signature to detect network connections initiated by threads executing in dynamically allocated (unbacked) memory.
• Unbacked Named Pipe Creation Detection: Created a signature to identify the creation of named pipes by threads in unbacked memory, potentially indicating P2P SMB beacons.
• Unbacked VEH Registration Detection: Included a signature to detect the registration of Vectored Exception Handlers (VEH) where the callback function points to unbacked memory.
• Unbacked Process Creation Detection: Added a signature to identify new child processes spawned by threads executing in unbacked memory.

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[gemini-code-assist]

Code Review

This pull request introduces a valuable set of signatures for detecting suspicious activities originating from unbacked memory. The overall implementation is solid, but I've identified a few areas for improvement. Specifically, there's a correctness issue in the UnbackedMemoryNetworkConnection signature that could cause it to miss detections, for which I've provided a fix. I also noticed a minor issue with a duplicated TTP entry and significant code duplication across the new signature classes. Addressing the code duplication by refactoring the common logic would greatly improve the long-term maintainability of this new module.