Emerging Threathightest

Possible Exploitation of Exchange RCE CVE-2021-42321

Detects log entries that appear in exploitation attempts against MS Exchange RCE CVE-2021-42321

Convert In Phoenix Studio

Open this Sigma rule in the converter with the YAML preloaded and ready for backend selection.

Launch
Florian Roth (Nextron Systems)Created Thu Nov 18Updated Tue Jul 12c92f1896-d1d2-43c3-92d5-7a5b35c217bb2021
Emerging Threat
Active Threat

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

Log Source
Windowsmsexchange-management
ProductWindows← raw: windows
Servicemsexchange-management← raw: msexchange-management
Detection Logic
Detection Logic1 selector
detection:
    selection:
        EventID:
            - 6
            - 8
        Data|contains:
            - 'Cmdlet failed. Cmdlet Get-App, '
            - 'Task Get-App throwing unhandled exception: System.InvalidCastException:'
    condition: selection
False Positives

Unknown, please report false positives via https://github.com/SigmaHQ/sigma/issues

MITRE ATT&CK

Other

detection.emerging-threats
Rule Metadata
Rule ID
c92f1896-d1d2-43c3-92d5-7a5b35c217bb
Status
test
Level
high
Type
Emerging Threat
Created
Thu Nov 18
Modified
Tue Jul 12
Path
rules-emerging-threats/2021/Exploits/CVE-2021-42321/win_exchange_cve_2021_42321.yml
Raw Tags
attack.lateral-movementattack.t1210detection.emerging-threats
View on GitHub