Sigma rule: Potential CVE-2021-41379 Exploitation Attempt

Rule

Title

Potential CVE-2021-41379 Exploitation Attempt

Status

test

Level

critical

Author

Florian Roth (Nextron Systems)

Date

2021-11-22

Modified

2024-12-01

File

rules-emerging-threats/2021/Exploits/CVE-2021-41379/proc_creation_win_exploit_cve_2021_41379.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects potential exploitation attempts of CVE-2021-41379 (InstallerFileTakeOver), a local privilege escalation (LPE) vulnerability where the attacker spawns a "cmd.exe" process as a child of Microsoft Edge elevation service "elevation_service" with "LOCAL_SYSTEM" rights

Log source

product

windows

category

process_creation

Detection

selection_img:
    - Image|endswith:
          - '\cmd.exe'
          - '\powershell.exe'
          - '\pwsh.exe'
    - OriginalFileName:
          - 'Cmd.Exe'
          - 'PowerShell.EXE'
          - 'pwsh.dll'
selection_parent:
    ParentImage|endswith: '\elevation_service.exe'
    IntegrityLevel:
        - 'System'
        - 'S-1-16-16384' # System
condition: all of selection_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.privilege-escalation
• attack.t1068
• cve.2021-41379
• detection.emerging-threats

CVEs this rule names

• CVE-2021-41379

MITRE ATT&CK ids this rule names

• T1068

References

• https://web.archive.org/web/20220421061949/https://github.com/klinix5/InstallerFileTakeOver
• https://www.bleepingcomputer.com/news/microsoft/new-windows-zero-day-with-public-exploit-lets-you-become-an-admin/
• https://www.zerodayinitiative.com/advisories/ZDI-21-1308/
• https://www.logpoint.com/en/blog/detecting-privilege-escalation-zero-day-cve-2021-41379/

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules-emerging-threats/2021/Exploits/CVE-2021-41379/proc_creation_win_exploit_cve_2021_41379.yml