Sigma rule: Potentially Suspicious ASP.NET Compilation Via AspNetCompiler

Rule

Title

Potentially Suspicious ASP.NET Compilation Via AspNetCompiler

Status

test

Level

high

Author

Nasreddine Bencherchali (Nextron Systems)

Date

2023-08-14

Modified

2025-02-24

File

rules/windows/process_creation/proc_creation_win_aspnet_compiler_susp_paths.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects execution of "aspnet_compiler.exe" with potentially suspicious paths for compilation.

Log source

product

windows

category

process_creation

Detection

selection:
    Image|contains:
        - ':\Windows\Microsoft.NET\Framework\'
        - ':\Windows\Microsoft.NET\Framework64\'
        - ':\Windows\Microsoft.NET\FrameworkArm\'
        - ':\Windows\Microsoft.NET\FrameworkArm64\'
    Image|endswith: '\aspnet_compiler.exe'
    CommandLine|contains:
        # Note: add other potential suspicious paths
        - '\Users\Public\'
        - '\AppData\Local\Temp\'
        - '\AppData\Local\Roaming\'
        - ':\Temp\'
        - ':\Windows\Temp\'
        - ':\Windows\System32\Tasks\'
        - ':\Windows\Tasks\'
condition: selection

False positives (as the rule lists them)

• Unknown

Tags

• attack.execution
• attack.stealth
• attack.t1127

MITRE ATT&CK ids this rule names

• T1127

Related rules

• 9ccba514-7cb6-4c5c-b377-700758f2f120 (similar)
• 4c7f49ee-2638-43bb-b85b-ce676c30b260 (similar)
• a01b8329-5953-4f73-ae2d-aa01e1f35f00 (similar)

References

• https://lolbas-project.github.io/lolbas/Binaries/Aspnet_Compiler/
• https://ijustwannared.team/2020/08/01/the-curious-case-of-aspnet_compiler-exe/

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/process_creation/proc_creation_win_aspnet_compiler_susp_paths.yml