Ceplin Command Identifier

Identifier / Programs / Windows

aspnet_compiler.exe

aspnet_compiler.exe file version info (xCyclopedia)

LOLBAS AWL Bypass 2 Sigma rules name it 1 ATT&CK technique 1 documented command 4 known copies with hashes

Opens the identifier with your command. It is read in your browser and sent nowhere.

How aspnet_compiler.exe is abused

documented by LOLBAS

AWL Bypass T1127 Trusted Developer Utilities Proxy Execution

-v
-p
-f
-u

Each abuse is LOLBAS's category and the options and words it uses; the full write-up is on LOLBAS's page for aspnet_compiler.exe.

1 documented command

from LOLBAS, each read by the identifier

AWL Bypass T1127 Trusted Developer Utilities Proxy Execution User privileges

Execute C# code with the Build Provider and proper folder structure in place.

C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_compiler.exe -v none -p C:\users\cpl.internal\desktop\asptest\ -f C:\users\cpl.internal\desktop\asptest\none -u
Identify

Trips 1 Sigma rule: mediumAspNetCompiler Execution by frack113

The command the identifier reads trips a Sigma process-creation rule. These commands and their descriptions are from LOLBAS’s entry for aspnet_compiler.exe, by Jimmy (@bohops), at commit 2056cb766250 of 2026-09-26, under the GPL-3.0 and LOLBAS’s notice, with no warranty. Changed: Markdown is shown formatted. The source is in lolbas-gtfobins-commands.json.gz, and the full entry is on LOLBAS’s page for aspnet_compiler.exe. The identifier reads it with LOLBAS’s placeholders filled in: a URL as https://example.com/file, a share as \\192.0.2.10\share\file, a path as C:\Data\file and a command as calc.exe.

What detects it

Sigma process creation rules
highPotentially Suspicious ASP.NET Compilation Via AspNetCompilerNasreddine Bencherchali (Nextron Systems)
T1127Trusted Developer Utilities Proxy Execution

Is it the real aspnet_compiler.exe?

file version info and known copies
Installed inC:\Windows\Microsoft.NET\Framework64\v4.0.30319\
C:\Windows\Microsoft.NET\Framework\v4.0.30319\
Signed byMicrosoft Windows
ProductMicrosoft .NET Framework, Microsoft Corporation
Descriptionaspnet_compiler.exe

4 known copies

4.8.4161.0 built by: NET48REL1 · C:\WINDOWS\Microsoft.NET\Framework64\v4.0.30319\aspnet_compiler.exe · signed by Microsoft Windows

39bb2299b678812b87919543d83377abb77d887e504aa418c1787889169332dc

4.8.4161.0 built by: NET48REL1 · C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\aspnet_compiler.exe · signed by Microsoft Windows

ed0d718e30178e817fb642e787adea679c8843c16142aaa76fed93eb75569e63

4.8.4084.0 built by: NET48REL1 · C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_compiler.exe · signed by Microsoft Windows

99a2c778c9a6486639d0aff1a7d2d494c2b0dc4c7913ebcb7bfea50a2f1d0b09

4.8.4084.0 built by: NET48REL1 · C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_compiler.exe · signed by Microsoft Windows

9ed0aa0a40c864f65ff867fd6b8491467786ce1bc60fd1e55f300a0fae5a77b4

From the file’s version info and the copies recorded by xCyclopedia (MIT). A copy in another folder, signed by someone else or with another hash is not necessarily malicious, but it is worth a closer look. In Ceplin, "<sha256>".whatis() says which known copy a hash is.