Sigma rule: Assembly DLL Creation Via AspNetCompiler

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-d6f3af7ae910, updated 2023-08-14T00:00:00.000Z.

Rule

Title
Assembly DLL Creation Via AspNetCompiler
Status
test
Level
medium
Author
Nasreddine Bencherchali (Nextron Systems)
Date
2023-08-14
File
rules/windows/file/file_event/file_event_win_aspnet_temp_files.yml
Commit
ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects the creation of new DLL assembly files by "aspnet_compiler.exe", which could be a sign of "aspnet_compiler" abuse to proxy execution through a build provider.

Log source

product
windows
category
file_event

Detection

selection:
    Image|endswith: '\aspnet_compiler.exe'
    TargetFilename|contains|all:
        - '\Temporary ASP.NET Files\'
        - '\assembly\tmp\'
        - '.dll'
condition: selection

False positives (as the rule lists them)

  • Legitimate assembly compilation using a build provider

Tags

  • attack.execution

Related rules

References

  • Internal Research

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/file/file_event/file_event_win_aspnet_temp_files.yml

Sources and licences

  • SigmaHQ

    "Assembly DLL Creation Via AspNetCompiler" by Nasreddine Bencherchali (Nextron Systems) (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/file/file_event/file_event_win_aspnet_temp_files.yml.
    Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License

    Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: Assembly DLL Creation Via AspNetCompiler",
entity page, dataset version ref-d6f3af7ae910, updated 2023-08-14T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/4c7f49ee-2638-43bb-b85b-ce676c30b260 (accessed 2026-11-03).
Underlying source: SigmaHQ rule 4c7f49ee-2638-43bb-b85b-ce676c30b260, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.