Identifier / Programs / Windows
microsoft.workflow.compiler.exe
Microsoft.Workflow.Compiler.exe file version info (xCyclopedia)
LOLBAS Execute, AWL Bypass 3 Sigma rules name it 1 ATT&CK technique 3 documented commands 2 known copies with hashes
How microsoft.workflow.compiler.exe is abused
Execute T1127 Trusted Developer Utilities Proxy Execution
AWL Bypass T1127 Trusted Developer Utilities Proxy Execution
Each abuse is LOLBAS's category and the options and words it uses; the full write-up is on LOLBAS's page for microsoft.workflow.compiler.exe.
3 documented commands
Execute T1127 Trusted Developer Utilities Proxy Execution User privileges
Compile and execute C# or VB.net code in a XOML file referenced in the first argument (any extension accepted).
Microsoft.Workflow.Compiler.exe {PATH} {PATH:.log}IdentifyTrips 1 Sigma rule: mediumMicrosoft Workflow Compiler Execution by Nik Seetharaman, frack113
Execute T1127 Trusted Developer Utilities Proxy Execution User privileges
Compile and execute C# or VB.net code in a XOML file referenced in the test.txt file.
Microsoft.Workflow.Compiler.exe {PATH} {PATH:.log}IdentifyTrips 1 Sigma rule: mediumMicrosoft Workflow Compiler Execution by Nik Seetharaman, frack113
AWL Bypass T1127 Trusted Developer Utilities Proxy Execution User privileges
Compile and execute C# or VB.net code in a XOML file referenced in the test.txt file.
Microsoft.Workflow.Compiler.exe {PATH} {PATH:.log}IdentifyTrips 1 Sigma rule: mediumMicrosoft Workflow Compiler Execution by Nik Seetharaman, frack113
All 3 commands the identifier reads trip a Sigma process-creation rule. These commands and their descriptions are from LOLBAS’s entry for microsoft.workflow.compiler.exe, by Conor Richard, 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 microsoft.workflow.compiler.exe. The identifier reads each 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 microsoft.workflow.compiler.exe?
C:\Windows\Microsoft.NET\Framework\v4.0.30319\2 known copies
4.8.4161.0 built by: NET48REL1 · C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\Microsoft.Workflow.Compiler.exe · signed by Microsoft Windows
585f531a76b897d0f480de1060fa962a132190524479aa2de624e6d33fca03914.8.4084.0 built by: NET48REL1 · C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Workflow.Compiler.exe · signed by Microsoft Windows
698be205bc3344d60a2d746d11a80174887b07fde82a01cfbb835a555064c9d9From 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.