Potential Rcdll.DLL Sideloading — Sigma Rule

Rule metadata and linked tags

Author: X__Junior (Nextron Systems). Source status: test; severity: high. Source dates: 2023-03-13 / 2023-03-15.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 39aea3a5e2e88ef982e90c7b6ea104bb575d3380276f9bc4bb871cdc8f10a46f

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 Rcdll.DLL Sideloading
id: 6e78b74f-c762-4800-82ad-f66787f10c8a
status: test
description: Detects potential DLL sideloading of rcdll.dll
references:
    - https://www.trendmicro.com/en_us/research/23/c/iron-tiger-sysupdate-adds-linux-targeting.html
author: X__Junior (Nextron Systems)
date: 2023-03-13
modified: 2023-03-15
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.execution
    - attack.stealth
    - attack.t1574.001
logsource:
    category: image_load
    product: windows
detection:
    selection:
        ImageLoaded|endswith: '\rcdll.dll'
    filter:
        ImageLoaded|startswith:
            - 'C:\Program Files (x86)\Microsoft Visual Studio\'
            - 'C:\Program Files (x86)\Windows Kits\'
    condition: selection and not filter
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://www.trendmicro.com/en_us/research/23/c/iron-tiger-sysupdate-adds-linux-targeting.html