Detection rules › Sigma
Suspicious Obfuscated PowerShell Code
Detects suspicious UTF16 and base64 encoded and often obfuscated PowerShell code often used in command lines
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
or:
CommandLine|contains: AALQBiAHgAbwByACAAMAB4A
CommandLine|contains: AC4ASQBuAHYAbwBrAGUAKAApACAAfAAg
CommandLine|contains: AHsAMAB9AHsAMwB9ACIAIAAtAGYAI
CommandLine|contains: AHsAMAB9AHsAMwB9ACcAIAAtAGYAI
CommandLine|contains: AHsAMQB9AHsAMAB9ACIAIAAtAGYAI
CommandLine|contains: AHsAMQB9AHsAMAB9ACcAIAAtAGYAI
CommandLine|contains: AHsAMgB9AHsAMAB9ACIAIAAtAGYAI
CommandLine|contains: AHsAMgB9AHsAMAB9ACcAIAAtAGYAI
CommandLine|contains: ALgBJAG4AdgBvAGsAZQAoACkAIAB8AC
CommandLine|contains: AewAwAH0AewAzAH0AIgAgAC0AZgAg
CommandLine|contains: AewAwAH0AewAzAH0AJwAgAC0AZgAg
CommandLine|contains: AewAxAH0AewAwAH0AIgAgAC0AZgAg
CommandLine|contains: AewAxAH0AewAwAH0AJwAgAC0AZgAg
CommandLine|contains: AewAyAH0AewAwAH0AIgAgAC0AZgAg
CommandLine|contains: AewAyAH0AewAwAH0AJwAgAC0AZgAg
CommandLine|contains: AuAEkAbgB2AG8AawBlACgAKQAgAHwAI
CommandLine|contains: B7ADAAfQB7ADMAfQAiACAALQBmAC
CommandLine|contains: B7ADAAfQB7ADMAfQAnACAALQBmAC
CommandLine|contains: B7ADEAfQB7ADAAfQAiACAALQBmAC
CommandLine|contains: B7ADEAfQB7ADAAfQAnACAALQBmAC
CommandLine|contains: B7ADIAfQB7ADAAfQAiACAALQBmAC
CommandLine|contains: B7ADIAfQB7ADAAfQAnACAALQBmAC
CommandLine|contains: IAAtAGIAeABvAHIAIAAwAHgA
CommandLine|contains: gAC0AYgB4AG8AcgAgADAAeA
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 |
|