Detect Component Object Model in Elastic Security
Adversaries abuse the Windows Component Object Model (COM) to execute arbitrary code locally. COM is a binary interface standard enabling inter-process communication between software objects through defined interfaces. Threat actors leverage COM by instantiating known objects (WScript.Shell, Shell.Application, MMC20.Application, Schedule.Service) via scripting hosts, hijacking COM object registrations in HKCU to redirect execution to malicious DLLs, or using elevated COM interfaces (CMLuaUtil) to bypass User Account Control. Real-world use includes TrickBot and Latrodectus creating scheduled tasks via ITaskService, MuddyWater executing payloads via DCOM loopback, Gamaredon injecting macros via Microsoft.Office.Interop objects, and Raspberry Robin abusing CMLuaUtil for UAC bypass. Unlike DCOM (T1021.003), this technique focuses on local COM execution rather than remote lateral movement.
MITRE ATT&CK
- Tactic
- Execution
- Technique
- T1559 Inter-Process Communication
- Sub-technique
- T1559.001 Component Object Model
- Canonical reference
- https://attack.mitre.org/techniques/T1559/001/
Elastic Detection Query
sequence by host.name with maxspan=5m
[
any where event.category == "process" and
process.name in~ ("powershell.exe", "pwsh.exe", "wscript.exe", "cscript.exe", "mshta.exe") and
(
process.args : ("-ComObject", "*CreateObject(*", "*GetTypeFromCLSID*", "*CreateInstance*") or
process.command_line : ("*MMC20.Application*", "*ShellWindows*", "*ShellBrowserWindow*", "*WScript.Shell*", "*Shell.Application*", "*Schedule.Service*", "*CMLuaUtil*", "*InternetExplorer.Application*", "*Microsoft.Office.Interop*", "*49B2791A*", "*9BA05972*", "*C08AFD90*", "*6EDD6D74*", "*0F87369F*")
)
] by process.entity_id
pipe
sequence by host.name with maxspan=30s
[
process where event.type == "start" and
process.parent.name : "dllhost.exe" and
process.name in~ ("cmd.exe", "powershell.exe", "pwsh.exe", "wscript.exe", "cscript.exe", "mshta.exe", "rundll32.exe", "regsvr32.exe", "certutil.exe", "net.exe", "net1.exe", "whoami.exe", "ipconfig.exe", "curl.exe", "wget.exe", "bitsadmin.exe")
] by process.entity_id
/* Alternate: COM Hijacking via registry */
/* registry where registry.path : "*\\SOFTWARE\\Classes\\CLSID\\*" and
registry.value in~ ("InProcServer32", "LocalServer32", "InProcServer") and
not registry.data.strings : ("C:\\Windows\\System32\\*", "C:\\Program Files\\*", "C:\\Program Files (x86)\\*") */Detects Windows COM abuse (T1559.001) across three behavioral patterns: (1) script hosts invoking suspicious COM objects or using COM instantiation patterns, (2) the COM surrogate process dllhost.exe spawning unexpected shell/utility children, and (3) COM hijacking via HKCU CLSID registry key modification to redirect execution. Covers TrickBot ITaskService abuse, MuddyWater DCOM loopback, and CMLuaUtil UAC bypass patterns.
Data Sources
Required Tables
False Positives & Tuning
- Legitimate administrative scripts that use COM objects such as WScript.Shell or Shell.Application for automation tasks like software deployment or configuration management
- dllhost.exe legitimately spawns child processes during thumbnail generation, Windows Search indexing, or when hosting out-of-process COM servers for applications like Office or Windows Explorer
- Enterprise software packaging tools (SCCM, PDQ Deploy, Ansible) may invoke COM interfaces for system configuration and will trigger the script-host COM pattern
Other platforms for T1559.001
Testing Methodology
Validate this detection against 4 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 1Scheduled Task Creation via ITaskService COM Interface
Expected signal: Sysmon Event ID 1: Process Create with Image=powershell.exe, CommandLine containing 'Schedule.Service' and 'ITaskService'. Windows Task Scheduler Operational log Event ID 106 (task registered) for 'df00tech-COM-test'. Security Event ID 4698 (scheduled task created) if task auditing is enabled. PowerShell Script Block Log Event ID 4104 with the full COM invocation code.
- Test 2Shell.Application COM Object Code Execution
Expected signal: Sysmon Event ID 1: Process Create for powershell.exe with CommandLine containing 'Shell.Application' and 'ShellExecute'. Second Sysmon Event ID 1 for calc.exe with ParentImage=explorer.exe or svchost.exe (the COM process host — ShellExecute routes through explorer.exe's COM server). Security Event ID 4688 for calc.exe process creation. PowerShell Script Block Log Event ID 4104.
- Test 3WScript.Shell COM Execution with Run Method
Expected signal: Sysmon Event ID 1: powershell.exe with 'WScript.Shell' in CommandLine. Sysmon Event ID 1: cmd.exe spawned (parent will be wscript.exe or svchost.exe depending on activation context, NOT powershell.exe). Sysmon Event ID 11: file create for df00tech-com-test.txt. PowerShell Script Block Log Event ID 4104.
- Test 4COM Hijacking via HKCU CLSID Registration
Expected signal: Sysmon Event ID 12 (Registry Object Create): TargetObject=HKCU\Software\Classes\CLSID\{DF000001-...}\InProcServer32. Sysmon Event ID 13 (Registry Value Set): TargetObject containing InProcServer32 with Details=%APPDATA%\df00tech-evil.dll. Security Event ID 4657 (registry value modified) if object access auditing is enabled. The ThreadingModel value is a hallmark of legitimate InProcServer32 registrations that malware mimics.
References (10)
- https://attack.mitre.org/techniques/T1559/001/
- https://www.fireeye.com/blog/threat-research/2019/06/hunting-com-objects.html
- https://msdn.microsoft.com/library/windows/desktop/ms680573.aspx
- https://enigma0x3.net/2017/01/05/lateral-movement-using-the-mmc20-application-com-object/
- https://googleprojectzero.blogspot.com/2018/04/windows-exploitation-tricks-exploiting.html
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1559.001/T1559.001.md
- https://learn.microsoft.com/en-us/windows/win32/com/com-technical-overview
- https://learn.microsoft.com/en-us/defender-endpoint/advanced-hunting-deviceregistryevents-table
- https://www.elastic.co/security-labs/exploring-the-latrodectus-payload
- https://www.welivesecurity.com/2020/10/02/eset-discovers-trickbot-new-module-targeting/
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