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
How aspnet_compiler.exe is abused
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
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 -uIdentifyTrips 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
Is it the real aspnet_compiler.exe?
C:\Windows\Microsoft.NET\Framework64\v4.0.30319\C:\Windows\Microsoft.NET\Framework\v4.0.30319\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
39bb2299b678812b87919543d83377abb77d887e504aa418c1787889169332dc4.8.4161.0 built by: NET48REL1 · C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\aspnet_compiler.exe · signed by Microsoft Windows
ed0d718e30178e817fb642e787adea679c8843c16142aaa76fed93eb75569e634.8.4084.0 built by: NET48REL1 · C:\Windows\Microsoft.NET\Framework\v4.0.30319\aspnet_compiler.exe · signed by Microsoft Windows
99a2c778c9a6486639d0aff1a7d2d494c2b0dc4c7913ebcb7bfea50a2f1d0b094.8.4084.0 built by: NET48REL1 · C:\Windows\Microsoft.NET\Framework64\v4.0.30319\aspnet_compiler.exe · signed by Microsoft Windows
9ed0aa0a40c864f65ff867fd6b8491467786ce1bc60fd1e55f300a0fae5a77b4From 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.