Potential Vcruntime140 DLL Sideloading — Sigma Rule

Rule metadata and linked tags

Author: Swachchhanda Shrawan Poudel (Nextron Systems). Source status: experimental; severity: high. Source dates: 2026-01-12 / 2026-05-18.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: f56054e386eab3d8aeeef57dd255606acb262dc718cb0f0527234e7d14b39393

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 Vcruntime140 DLL Sideloading
id: d7a63acb-1284-49bc-bfea-7771146c8b1c
status: experimental
description: |
    Detects potential DLL sideloading of vcruntime140.dll, a common C++ runtime library.
    Threat actors have been observed using DLL sideloading techniques to load malicious payloads under the guise of legitimate applications such as SqlWriter, SqlDumper etc.
    Notably, APT29 has been documented leveraging WinELOADER to sideload vcruntime140.dll for executing malicious code.
references:
    - https://www.mandiant.com/resources/blog/apt29-wineloader-german-political-parties
    - https://www.zscaler.com/blogs/security-research/european-diplomats-targeted-spikedwine-wineloader
    - https://www.nextron-systems.com/2023/09/15/detecting-janelarat-with-yara-and-thor/
author: Swachchhanda Shrawan Poudel (Nextron Systems)
date: 2026-01-12
modified: 2026-05-18
tags:
    - attack.persistence
    - attack.privilege-escalation
    - attack.execution
    - attack.stealth
    - attack.t1574.001
logsource:
    category: image_load
    product: windows
detection:
    selection:
        ImageLoaded|endswith: '\vcruntime140.dll'
    filter_main_legitimate_path:
        ImageLoaded|startswith:
            - 'C:\Windows\System32\'
            - 'C:\Windows\SysWOW64\'
            - 'C:\Program Files\'
            - 'C:\Program Files (x86)\'
    filter_main_legitimate_signer:
        Signed: true
        SignatureStatus: 'Valid'
        Description|endswith: 'C Runtime Library'
    filter_optional_onedrive:
        Image|startswith: 'C:\Users\'
        Image|contains: '\AppData\Local\Microsoft\OneDrive\'
    condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*
falsepositives:
    - Unknown
level: high
regression_tests_path: regression_data/rules/windows/image_load/image_load_side_load_vcruntime140/info.yml

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://www.mandiant.com/resources/blog/apt29-wineloader-german-political-parties
• https://www.zscaler.com/blogs/security-research/european-diplomats-targeted-spikedwine-wineloader
• https://www.nextron-systems.com/2023/09/15/detecting-janelarat-with-yara-and-thor/