Detection rules › Sigma
PPL Tampering Via WerFaultSecure
Detects potential abuse of WerFaultSecure.exe to dump Protected Process Light (PPL) processes like LSASS or to freeze security solutions (EDR/antivirus). This technique is used by tools such as EDR-Freeze and WSASS to bypass PPL protections and access sensitive information or disable security software. Distinct command line patterns help identify the specific tool: - WSASS usage typically shows: "WSASS.exe WerFaultSecure.exe [PID]" in ParentCommandLine - EDR-Freeze usage typically shows: "EDR-Freeze_[version].exe [PID] [timeout]" in ParentCommandLine Legitimate debugging operations using WerFaultSecure are rare in production environments and should be investigated.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Defense Evasion | T1562.001 Impair Defenses: Disable or Modify Tools |
| Credential Access | T1003.001 OS Credential Dumping: LSASS Memory |
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Sysmon | 1 | Process creation |
Stages and Predicates
Stage 1: all of selection_image
or:
Image|endswith: '\WerFaultSecure.exe'
OriginalFileName: WerFaultSecure.exe
Stage 2: all of selection_args
CommandLine|contains: ' /cancel '
CommandLine|contains: ' /encfile '
CommandLine|contains: ' /h '
CommandLine|contains: ' /pid '
CommandLine|contains: ' /tid '
CommandLine|contains: ' /type '
CommandLine|contains: ' 268310'
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
CommandLine | match |
|
Image | ends_with |
|
OriginalFileName | eq |
|