Detect InstallUtil in Elastic Security
Adversaries may use InstallUtil to proxy execution of code through a trusted Windows utility. InstallUtil is a command-line utility that allows for installation and uninstallation of resources by executing specific installer components specified in .NET binaries. The InstallUtil binary is digitally signed by Microsoft and located in the .NET directories. InstallUtil may also bypass application control by using the [System.ComponentModel.RunInstaller(true)] attribute decorator pattern. Known users of this technique include Mustang Panda (Beacon stager), WhisperGate (Windows Defender disable), Chaes malware, Saint Bot, and the Covenant C2 framework.
MITRE ATT&CK
- Tactic
- Defense Evasion
- Technique
- T1218 System Binary Proxy Execution
- Sub-technique
- T1218.004 InstallUtil
- Canonical reference
- https://attack.mitre.org/techniques/T1218/004/
Elastic Detection Query
process where event.type == "start" and
(
(
process.name : "installutil.exe" and
(
process.command_line : ("*\\Temp\\*", "*\\AppData\\*", "*\\Downloads\\*", "*\\Public\\*", "*\\ProgramData\\*", "*\\Users\\*") or
process.parent.name : ("cmd.exe", "powershell.exe", "wscript.exe", "cscript.exe", "mshta.exe", "winword.exe", "excel.exe") or
process.command_line : ("*/u *", "*/uninstall*", "*/logfile*")
)
) or
(
process.parent.name : "installutil.exe" and
process.name : ("cmd.exe", "powershell.exe", "wscript.exe", "cscript.exe", "rundll32.exe", "regsvr32.exe", "net.exe")
)
)Detects T1218.004 InstallUtil proxy execution abuse using Elastic EQL against Endpoint or Sysmon process events. Flags InstallUtil launched from interpreter or Office parent processes, invoked with payloads in user-writable directories or uninstall flags, and InstallUtil acting as a parent to common post-exploitation binaries.
Data Sources
Required Tables
False Positives & Tuning
- Enterprise software deployment platforms such as SCCM or PDQ Deploy that invoke InstallUtil via a cmd.exe or PowerShell wrapper as part of managed .NET application installation workflows
- Visual Studio or MSBuild post-build event steps on developer workstations that register .NET installer components from build output directories under the user profile
- Security or monitoring agents that stage components in ProgramData and use InstallUtil for COM or Windows service registration during initial product setup
Other platforms for T1218.004
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1InstallUtil Execution from Temp Directory
Expected signal: Sysmon Event ID 1: installutil.exe with Temp path in command line, /logfile and /logtoconsole flags. Security Event ID 4688 for the process. Sysmon Event ID 7 (Image Load) for the DLL being loaded.
- Test 2InstallUtil with Uninstall Flag
Expected signal: Sysmon Event ID 1: installutil.exe with /u flag and temp path. Security Event ID 4688. The process will fail if the file doesn't exist or isn't a valid installer assembly, but the process creation event still fires.
- Test 3InstallUtil Invoked from PowerShell
Expected signal: Sysmon Event ID 1: powershell.exe followed by installutil.exe with ParentImage=powershell.exe. Both SuspiciousParent and SuspiciousPath indicators fire. Security Event ID 4688 for both processes.
References (7)
- https://attack.mitre.org/techniques/T1218/004/
- https://lolbas-project.github.io/lolbas/Binaries/Installutil/
- https://msdn.microsoft.com/en-us/library/50614e95.aspx
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1218.004/T1218.004.md
- https://unit42.paloaltonetworks.com/attackers-tactics-and-techniques-in-unsecured-docker-daemons-revealed/
- https://www.cybereason.com/blog/operation-cobalt-kitty-apt
- https://www.anomali.com/blog/mustang-panda-threat-actor-targets-minority-groups-journalists-and-activists
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