Detect CVE-2012-1854 - Microsoft VBA Insecure Library Loading (DLL Hijacking) in Google Chronicle
Detects exploitation of CVE-2012-1854, a DLL hijacking vulnerability in Microsoft Visual Basic for Applications (VBA). Attackers can place a malicious DLL in a directory searched before the legitimate library path, causing Office applications loading VBA to execute attacker-controlled code. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.
MITRE ATT&CK
YARA-L Detection Query
rule cve_2012_1854_vba_dll_hijacking {
meta:
author = "df00tech Detection Engineering"
description = "Detects VBA DLL hijacking via CVE-2012-1854 - Office apps loading VBA DLLs from non-standard paths"
severity = "HIGH"
priority = "HIGH"
reference = "https://nvd.nist.gov/vuln/detail/CVE-2012-1854"
events:
$e.metadata.event_type = "PROCESS_MODULE_LOAD"
$e.principal.process.file.full_path = /(?i)(WINWORD|EXCEL|POWERPNT|OUTLOOK|MSACCESS|MSPUB|VISIO)\.EXE$/
$e.target.process.file.full_path = /(?i)(vbe7|vba7|vbe6|vba6|msvbvm60|msvbvm50)\.dll$/
$e.target.process.file.full_path = /(?i)\\(Users|AppData|Temp|Downloads|Desktop)\\/
condition:
$e
}Chronicle YARA-L rule detecting CVE-2012-1854 exploitation by monitoring PROCESS_MODULE_LOAD events where Office applications load VBA DLLs from suspicious user-writable directories.
Data Sources
Required Tables
False Positives & Tuning
- Legitimate portable Office installations with non-standard base paths
- Developer environments with custom Office component deployments
- Automated QA environments loading Office DLLs from test directories
- Enterprise deployments using non-default Office installation directories
Other platforms for CVE-2012-1854
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 1VBA DLL Hijack - Place Malicious DLL in Temp Directory
Expected signal: Sysmon Event ID 7 showing WINWORD.EXE loading vbe7.dll from %TEMP% path; DeviceImageLoadEvents in MDE showing FolderPath containing \Temp\
- Test 2VBA DLL Hijack - Place Malicious DLL in Downloads Directory
Expected signal: Sysmon ImageLoad event with ImageLoaded path in \Downloads\; Windows Security log showing file creation event in Downloads directory followed by Office process DLL load
- Test 3VBA DLL Hijack - Simulate Document-Triggered DLL Load via PowerShell
Expected signal: Sysmon Event ID 7 with POWERPNT.EXE as initiating process and vba7.dll loaded from TEMP\vba_hijack_test path; process creation event showing PowerShell as parent of POWERPNT
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