Detect Microsoft Office Remote Code Execution (CVE-2009-0238) in Elastic Security
CVE-2009-0238 is a remote code execution vulnerability in Microsoft Office (addressed in MS09-009) caused by improper handling of specially crafted Excel files, leading to arbitrary code execution in the context of the logged-on user. This vulnerability is listed in the CISA Known Exploited Vulnerabilities catalog and has been actively exploited in the wild via malicious Office documents delivered through phishing campaigns.
MITRE ATT&CK
- Tactic
- Initial Access Execution TA0059
Elastic Detection Query
process where event.type == "start"
and process.parent.name in~ ("excel.exe", "winword.exe", "powerpnt.exe")
and process.name in~ ("cmd.exe", "powershell.exe", "wscript.exe", "cscript.exe", "mshta.exe", "regsvr32.exe", "rundll32.exe", "certutil.exe")EQL sequence detecting Microsoft Office processes spawning shell or scripting engine child processes, a strong indicator of document-based exploitation as seen in CVE-2009-0238.
Data Sources
Required Tables
False Positives & Tuning
- Macro-enabled Office documents used in legitimate IT workflows
- Security tooling that opens Office documents programmatically and triggers child processes
- Test environments executing Office-based automation scripts
Other platforms for CVE-2009-0238
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 1Office Spawning PowerShell Encoded Command
Expected signal: Sysmon Event ID 1 showing EXCEL.EXE as parent process of powershell.exe with a -EncodedCommand argument; DeviceProcessEvents in MDE capturing the parent-child chain
- Test 2Office Spawning CMD with Network Download
Expected signal: Sysmon Event ID 1 for cmd.exe and certutil.exe processes; Sysmon Event ID 3 (Network Connect) from certutil.exe to 127.0.0.1:8888; Sysmon Event ID 11 for test_artifact.exe creation in TEMP
- Test 3Malicious Excel File Macro Execution Simulation via WScript
Expected signal: Sysmon Event ID 11 for sim_payload.vbs creation; Sysmon Event ID 1 for wscript.exe and subsequently calc.exe process creation; parent chain visible in EDR
Unlock Pro Content
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