Behavior-chain, platform-aware detection strategy for T1127 Trusted Developer Utilities Proxy Execution (Windows)

ID: DET0172
Domains: Enterprise
Analytics: AN0488
Version: 1.0
Created: 21 October 2025
Last Modified: 21 October 2025

Analytics

AN0488

A trusted/signed developer utility (parent) is executed in a non-developer context and (a) spawns suspicious children (e.g., powershell.exe, cmd.exe, rundll32.exe, regsvr32.exe, wscript.exe), (b) loads unsigned/user-writable DLLs, (c) writes and then runs a new PE from user-writable paths, and/or (d) immediately makes outbound network connections.

Log Sources
Data Component Name Channel
Process Creation (DC0032) WinEventLog:Security EventCode=4688
Module Load (DC0016) WinEventLog:Sysmon EventCode=7
File Creation (DC0039) WinEventLog:Sysmon EventCode=11
Network Connection Creation (DC0082) WinEventLog:Sysmon EventCode=3, 22
Process Metadata (DC0034) WinEventLog:AppLocker AppLocker audit/blocks showing developer utilities executing scripts/binaries outside policy
Mutable Elements
Field Description
TimeWindow Correlation window between developer utility execution, payload write, and network egress (e.g., 0–30 minutes).
AllowedUtilitiesList Org-specific list of dev utilities legitimately used on build/dev hosts to suppress noise.
DeveloperHosts List of known developer/build systems where these tools are expected; raise severity off-host.
SuspiciousChildList Child processes considered high-risk when spawned by dev utilities (powershell.exe, rundll32.exe, regsvr32.exe, cmd.exe, wscript.exe, mshta.exe).
RarePathRegex Regex of user-writable or atypical paths (e.g., %TEMP%, %APPDATA%, recycle bin, public profile) for payload drops.
UnsignedOrInvalidSignatureOnly Toggle to alert only when child/payload is unsigned or signature invalid to reduce noise.
ParentProcessAllowList Known orchestrators (e.g., CI/CD agents) that often run these utilities legitimately.
NetworkReputationThreshold Heuristic for rare/unknown destination (no DNS reputation, new domain, geo outside region).