Emerging Threatcriticaltest

Potential CVE-2021-41379 Exploitation Attempt

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

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Launch
Florian Roth (Nextron Systems)Created Mon Nov 22Updated Sun Dec 01af8bbce4-f751-46b4-8d91-82a33a736f612021
Emerging Threat
Active Threat

Developed to detect an active or emerging threat. Prioritize investigation of any alerts and correlate with threat intelligence.

Log Source
WindowsProcess Creation
ProductWindows← raw: windows
CategoryProcess Creation← raw: process_creation

Events generated when a new process is spawned on the system. Covers command-line arguments, parent/child relationships, and process metadata.

Detection Logic
Detection Logic2 selectors
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
Unknown

False positive likelihood has not been assessed. Additional context may be needed during triage.

MITRE ATT&CK

Other

cve.2021-41379detection.emerging-threats
Rule Metadata
Rule ID
af8bbce4-f751-46b4-8d91-82a33a736f61
Status
test
Level
critical
Type
Emerging Threat
Created
Mon Nov 22
Modified
Sun Dec 01
Path
rules-emerging-threats/2021/Exploits/CVE-2021-41379/proc_creation_win_exploit_cve_2021_41379.yml
Raw Tags
attack.privilege-escalationattack.t1068cve.2021-41379detection.emerging-threats
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