Suspicious Unsigned Dbghelp/Dbgcore DLL Loaded

Description

Detects the load of dbghelp/dbgcore DLL (used to make memory dumps) by suspicious processes. Tools like ProcessHacker and some attacker tradecract use MiniDumpWriteDump API found in dbghelp.dll or dbgcore.dll. As an example, SilentTrynity C2 Framework has a module that leverages this API to dump the contents of Lsass.exe and transfer it over the network back to the attacker's machine.

Query · sigma

selection:
  ImageLoaded|endswith:
  - \dbghelp.dll
  - \dbgcore.dll
  Signed: 'false'
condition: selection

Known false positives

  • Unknown
Raw source Suspicious Unsigned Dbghelp/Dbgcore DLL Loaded · Sigma
Esc
Published by SigmaHQ/sigma ↗, licensed under Detection Rule License 1.1 ↗. Reproduced here unmodified. 
title: Suspicious Unsigned Dbghelp/Dbgcore DLL Loaded
id: bdc64095-d59a-42a2-8588-71fd9c9d9abc
related:
    - id: 0e277796-5f23-4e49-a490-483131d4f6e1 # Suspicious Loading
      type: similar
status: test
description: |
    Detects the load of dbghelp/dbgcore DLL (used to make memory dumps) by suspicious processes.
    Tools like ProcessHacker and some attacker tradecract use MiniDumpWriteDump API found in dbghelp.dll or dbgcore.dll.
    As an example, SilentTrynity C2 Framework has a module that leverages this API to dump the contents of Lsass.exe and transfer it over the network back to the attacker's machine.
references:
    - https://learn.microsoft.com/en-us/windows/win32/api/minidumpapiset/nf-minidumpapiset-minidumpwritedump
    - https://www.pinvoke.net/default.aspx/dbghelp/MiniDumpWriteDump.html
    - https://medium.com/@fsx30/bypass-edrs-memory-protection-introduction-to-hooking-2efb21acffd6
author: Perez Diego (@darkquassar), oscd.community, Ecco
date: 2019-10-27
modified: 2022-12-09
tags:
    - attack.credential-access
    - attack.t1003.001
logsource:
    category: image_load
    product: windows
detection:
    selection:
        ImageLoaded|endswith:
            - '\dbghelp.dll'
            - '\dbgcore.dll'
        Signed: 'false'
    condition: selection
falsepositives:
    - Unknown
level: high

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