Sigma rule: HAFNIUM Exchange Exploitation Activity

Rule

Title

HAFNIUM Exchange Exploitation Activity

Status

test

Level

critical

Author

Florian Roth (Nextron Systems)

Date

2021-03-09

Modified

2023-03-09

File

rules-emerging-threats/2021/TA/HAFNIUM/proc_creation_win_apt_hafnium.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects activity observed by different researchers to be HAFNIUM group activity (or related) on Exchange servers

Log source

product

windows

category

process_creation

Detection

selection_attrib:
    CommandLine|contains|all:
        - 'attrib'
        - ' +h '
        - ' +s '
        - ' +r '
        - '.aspx'
selection_vsperfmon:
    - Image|contains: '\ProgramData\VSPerfMon\'
    - CommandLine|contains|all:
          - 'schtasks'
          - 'VSPerfMon'
selection_opera_1:
    Image|endswith: 'Opera_browser.exe'
    ParentImage|endswith:
        - '\services.exe'
        - '\svchost.exe'
selection_opera_2:
    Image|endswith: 'Users\Public\opera\Opera_browser.exe'
selection_vssadmin:
    CommandLine|contains|all:
        - 'vssadmin list shadows'
        - 'Temp\__output'
selection_makecab_1:
    Image|endswith: '\makecab.exe'
    CommandLine|contains|all:
        - 'inetpub\wwwroot\'
        - '.dmp.zip'
selection_makecab_2:
    Image|endswith: '\makecab.exe'
    CommandLine|contains:
        - 'Microsoft\Exchange Server\'
        - 'compressionmemory'
        - '.gif'
selection_7zip:
    CommandLine|contains|all:
        - ' -t7z '
        - 'C:\Programdata\pst'
        - '\it.zip'
selection_rundll32:
    CommandLine|contains|all:
        - '\comsvcs.dll'
        - 'Minidump'
        - 'full '
        - '\inetpub\wwwroot'
selection_other:
    CommandLine|contains:
        - 'Windows\Temp\xx.bat'
        - 'Windows\WwanSvcdcs'
        - 'Windows\Temp\cw.exe'
condition: 1 of selection*

False positives (as the rule lists them)

• Unlikely

Tags

• attack.privilege-escalation
• attack.execution
• attack.persistence
• attack.t1546
• attack.t1053
• attack.g0125
• detection.emerging-threats

MITRE ATT&CK ids this rule names

• G0125
• T1053
• T1546

References

• https://blog.truesec.com/2021/03/07/exchange-zero-day-proxylogon-and-hafnium/
• https://www.microsoft.com/security/blog/2021/03/02/hafnium-targeting-exchange-servers/
• https://discuss.elastic.co/t/detection-and-response-for-hafnium-activity/266289/3
• https://twitter.com/GadixCRK/status/1369313704869834753?s=20
• https://twitter.com/BleepinComputer/status/1372218235949617161

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/TA/HAFNIUM/proc_creation_win_apt_hafnium.yml