Detection rules › Sigma

AspNetCompiler Execution

Severity
medium
Author
frack113
Source
upstream

Detects execution of "aspnet_compiler.exe" which can be abused to compile and execute C# code.

MITRE ATT&CK coverage

TacticTechniques
Defense EvasionT1127 Trusted Developer Utilities Proxy Execution

Event coverage

ProviderEvent IDTitle
Sysmon1Process creation
Security-Auditing4688A new process has been created.

Stages and Predicates

Stage 1: selection

or:
Image|contains: ':\Windows\Microsoft.NET\Framework64\'
Image|contains: ':\Windows\Microsoft.NET\FrameworkArm64\'
Image|contains: ':\Windows\Microsoft.NET\FrameworkArm\'
Image|contains: ':\Windows\Microsoft.NET\Framework\'
Image|endswith: '\aspnet_compiler.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.

FieldKindValues
Imageends_with
  • \aspnet_compiler.exe corpus 3 (sigma 3)
Imagematch
  • :\Windows\Microsoft.NET\Framework64\ corpus 3 (sigma 3)
  • :\Windows\Microsoft.NET\FrameworkArm64\ corpus 3 (sigma 3)
  • :\Windows\Microsoft.NET\FrameworkArm\ corpus 3 (sigma 3)
  • :\Windows\Microsoft.NET\Framework\ corpus 3 (sigma 3)

Neighbors

Stricter alternatives (narrower than this rule)

The rules below may be useful if you find the current rule is too noisy / lacks specificity.