Detection rules › Sigma
Potential AMSI Bypass Via .NET Reflection
Detects Request to "amsiInitFailed" that can be used to disable AMSI Scanning
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Defense Evasion | T1562.001 Impair Defenses: Disable or Modify Tools |
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: 'NonPublic,Static'
CommandLine|contains: 'SetValue($null,$true)'
CommandLine|contains: '[Ref].Assembly.GetType'
CommandLine|contains: 'System.Management.Automation.AmsiUtils'
CommandLine|contains: amsiInitFailed
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 |
|