Sigma rule: HackTool - WSASS Execution

Rule

Title

HackTool - WSASS Execution

Status

experimental

Level

high

Author

Swachchhanda Shrawan Poudel (Nextron Systems)

Date

2025-11-23

Modified

2026-01-09

File

rules/windows/process_creation/proc_creation_win_hktl_wsass.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects execution of WSASS, a tool used to dump LSASS memory on Windows systems by leveraging WER's
(Windows Error Reporting) WerFaultSecure.EXE to bypass PPL (Protected Process Light) protections.

Log source

product

windows

category

process_creation

Detection

selection_img:
    Image|endswith: '\wsass.exe'
selection_hash:
    Hashes|contains: 'IMPHASH=32F5095C9BBDCACF28FD4060EB4DFC42'
selection_cli:
    # change to |re|i after Sigma v2.0 release
    # plain string without quotation marks as it has to match for both ' and "
    CommandLine|re: (?i)\.exe[\"\']?\s+[^\"]{0,64}werfaultsecure\.exe[\"\']?\s+\d{2,10} # wsass.exe "path to werfaultsecure" lsass_pid
condition: 1 of selection_*

False positives (as the rule lists them)

• Unlikely

Tags

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

MITRE ATT&CK ids this rule names

• T1003.001

References

• https://github.com/TwoSevenOneT/WSASS
• https://www.zerosalarium.com/2025/09/Dumping-LSASS-With-WER-On-Modern-Windows-11.html

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_creation/proc_creation_win_hktl_wsass.yml