Detect Component Object Model in CrowdStrike LogScale
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/
LogScale Detection Query
// Branch 1: Script host COM object instantiation
(
#event_simpleName = "ProcessRollup2"
| ImageFileName = /(powershell|pwsh|wscript|cscript|mshta)\.exe$/i
| CommandLine = /(-ComObject|CreateObject\(|GetTypeFromCLSID|activator.*CreateInstance|MMC20\.Application|ShellWindows|ShellBrowserWindow|WScript\.Shell|Shell\.Application|Schedule\.Service|CMLuaUtil|InternetExplorer\.Application|Microsoft\.Office\.Interop|49B2791A|9BA05972|C08AFD90|6EDD6D74|0F87369F)/i
| TargetProcessId != null
| eval DetectionSource = "ScriptCOMAbuse"
)
union
// Branch 2: dllhost.exe surrogate spawning suspicious child processes
(
#event_simpleName = "ProcessRollup2"
| ParentBaseFileName = /^dllhost\.exe$/i
| ImageFileName = /(cmd|powershell|pwsh|wscript|cscript|mshta|rundll32|regsvr32|certutil|net|net1|whoami|curl|wget|bitsadmin)\.exe$/i
| eval DetectionSource = "DllHostSurrogate"
)
union
// Branch 3: COM hijacking via HKCU CLSID registry write
(
#event_simpleName in ("RegGenericValueUpdate", "RegistryOperationCreate", "RegistryOperationUpdate")
| RegObjectName = /HKCU\\Software\\Classes\\CLSID/i
| RegObjectName = /(InProcServer32|LocalServer32|InProcServer)/i
| RegStringValue != /^(C:\\Windows\\System32|C:\\Program Files)/i
| eval DetectionSource = "COMHijacking"
)
| table(["@timestamp", "ComputerName", "UserName", "ImageFileName", "CommandLine", "ParentBaseFileName", "RegObjectName", "RegStringValue", "DetectionSource", "aid"])
| sort(field="@timestamp", order=desc)CrowdStrike LogScale (Humio) CQL detection for COM abuse (T1559.001) using Falcon endpoint telemetry. Covers three detection branches: ProcessRollup2 events where script hosts invoke COM objects by name or use COM instantiation APIs, dllhost.exe surrogate process spawning shell/utility children indicating a malicious COM server, and registry modification events recording HKCU CLSID writes pointing to non-system paths indicative of COM hijacking persistence. Uses Falcon native event types for high-fidelity process and registry telemetry.
Data Sources
Required Tables
False Positives & Tuning
- CrowdStrike Falcon sensors on workstations running enterprise automation tools (AutoIt, AutoHotKey, or Macro schedulers) that leverage COM for UI automation will generate high-volume ScriptCOMAbuse matches as these legitimately use CreateObject() and WScript.Shell
- Microsoft SCCM and Intune client agents use dllhost.exe-hosted COM servers for WMI and software inventory operations and may spawn cmd.exe or PowerShell subprocesses as part of legitimate client health workflows, triggering the DllHostSurrogate branch
- Legitimate user-mode COM server installations during application setup (e.g., Acrobat, VLC, or development tools registering shell extensions) will write HKCU\Software\Classes\CLSID entries pointing to non-system paths, generating COMHijacking alerts during installation
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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