Detection rules › Sigma
Uncommon Svchost Command Line Parameter
Detects instances of svchost.exe running with an unusual or uncommon command line parameter by excluding known legitimate or common patterns. This could point at a file masquerading as svchost, a process injection, or hollowing of a legitimate svchost instance.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Privilege Escalation | T1055 Process Injection, T1055.012 Process Injection: Process Hollowing |
| Defense Evasion | T1036.005 Masquerading: Match Legitimate Resource Name or Location, T1055 Process Injection, T1055.012 Process Injection: Process Hollowing |
Event coverage
| Provider | Event ID | Title |
|---|---|---|
| Sysmon | 1 | Process creation |
| Security-Auditing | 4688 | A new process has been created. |
Stages and Predicates
Stage 1: selection
Image|endswith: '\svchost.exe'
Stage 2: not 1 of filter_main_*
or:
CommandLine: ''
CommandLine: null
CommandLine|re: '-k\s\w{1,64}(\s?(-p|-s))?'
Stage 3: not 1 of filter_optional_*
or:
CommandLine: svchost.exe
ParentImage|endswith: '\MRT.exe'
CommandLine|contains: svchost.exe
ParentImage|endswith: '\MsMpEng.exe'
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 | eq |
|
CommandLine | match |
|
CommandLine | regex_match |
|
Image | ends_with |
|
ParentImage | ends_with |
|
Neighbors
Stricter alternatives (narrower than this rule)
The rules below may be useful if you find the current rule is too noisy / lacks specificity.
- Suspect Svchost Activity (adds 1 filter)