Sigma rule: Potential Credential Dumping Activity Via LSASS

Rule

Title

Potential Credential Dumping Activity Via LSASS

Status

test

Level

medium

Author

Samir Bousseaden, Michael Haag

Date

2019-04-03

Modified

2026-06-29

File

rules/windows/process_access/proc_access_win_lsass_memdump.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects process access requests to the LSASS process with specific call trace calls and access masks.
This behaviour is expressed by many credential dumping tools such as Mimikatz, NanoDump, Invoke-Mimikatz, Procdump and even the Taskmgr dumping feature.

Log source

product

windows

category

process_access

Detection

selection:
    TargetImage|endswith: '\lsass.exe'
    GrantedAccess|contains:
        - '0x1038'
        - '0x1438'
        - '0x143a'
        - '0x1fffff' # Too many false positives
        # - '0x01000'  # Too many false positives
        # - '0x1010'   # Too many false positives
        # - '0x1400'  # Too many false positives
        # - '0x1410' # Too many false positives
        # - '0x40'   # Too many false positives
    CallTrace|contains:
        - 'dbgcore.dll'
        - 'dbghelp.dll'
        - 'kernel32.dll'
        - 'kernelbase.dll'
        - 'ntdll.dll'
filter_main_system_user:
    SourceUser|contains: # Covers many language settings
        - 'AUTHORI'
        - 'AUTORI'
filter_optional_thor:
    CallTrace|contains|all:
        - ':\Windows\Temp\asgard2-agent\'
        - '\thor\thor64.exe+'
        - '|UNKNOWN('
    GrantedAccess: '0x103800'
filter_optional_sysmon:
    SourceImage|endswith:
        - ':\Windows\Sysmon64.exe'
        - ':\Windows\Sysmon64a.exe'
condition: selection and not 1 of filter_main_* and not 1 of filter_optional_*

False positives (as the rule lists them)

• Unknown

Tags

• attack.credential-access
• attack.t1003.001
• attack.s0002

MITRE ATT&CK ids this rule names

• S0002
• T1003.001

References

• https://web.archive.org/web/20230329170326/https://blog.menasec.net/2019/02/threat-hunting-21-procdump-or-taskmgr.html
• https://web.archive.org/web/20230208123920/https://cyberwardog.blogspot.com/2017/03/chronicles-of-threat-hunter-hunting-for_22.html
• https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1003.001/T1003.001.md
• https://research.splunk.com/endpoint/windows_possible_credential_dumping/

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_access/proc_access_win_lsass_memdump.yml