Potential 7za.DLL Sideloading — Sigma Rule

Rule metadata and linked tags

Author: X__Junior. Source status: test; severity: low. Source dates: 2023-06-09 / not supplied.

{
  "category": "image_load",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: dc5a49a0293d02c6ed35d5ed7925535f75548cf4cbb620625e08b6e277b23fd3

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Potential 7za.DLL Sideloading
id: 4f6edb78-5c21-42ab-a558-fd2a6fc1fd57
status: test
description: Detects potential DLL sideloading of "7za.dll"
references:
    - https://www.gov.pl/attachment/ee91f24d-3e67-436d-aa50-7fa56acf789d
author: X__Junior
date: 2023-06-09
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.execution
    - attack.stealth
    - attack.t1574.001
logsource:
    category: image_load
    product: windows
detection:
    selection:
        ImageLoaded|endswith: '\7za.dll'
    filter_main_legit_path:
        Image|startswith:
            - 'C:\Program Files (x86)\'
            - 'C:\Program Files\'
        ImageLoaded|startswith:
            - 'C:\Program Files (x86)\'
            - 'C:\Program Files\'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Legitimate third party application located in "AppData" may leverage this DLL to offer 7z compression functionality and may generate false positives. Apply additional filters as needed.
level: low

Original YAML and metadata in JSON

False positives

• Legitimate third party application located in "AppData" may leverage this DLL to offer 7z compression functionality and may generate false positives. Apply additional filters as needed.

Source references

• https://www.gov.pl/attachment/ee91f24d-3e67-436d-aa50-7fa56acf789d