Describe the behaviour you want to detect. SARA writes a starting Sigma rule with MITRE tags, false-positive guidance, and detection-engineering context. Anonymous, no account, best-effort generic detection.
title: Potential CVE-2012-1889 MSXML Exploitation Command Shell Execution
id: ee05f8f9-592c-4944-b7c7-3bad29ed5239
status: experimental
description: |
Detects potential exploitation of CVE-2012-1889 (Microsoft XML Core Services MSXML Vulnerability).
CVE-2012-1889 is a CISA KEV-listed remote code execution vulnerability exploited via malicious web content
or documents. Exploitation typically results in script interpreters (wscript.exe, cscript.exe, mshta.exe)
executing obfuscated commands or spawning command shells (cmd.exe, powershell.exe) to download or execute payloads.
CVSS: 9.3 (Critical) | KEV Status: Listed.
references:
- https://nvd.nist.gov/vuln/detail/CVE-2012-1889
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog
author: SARA Detection Engineering
date: 2026-08-18
tags:
- attack.execution
- attack.t1059.001
- attack.t1059.003
- attack.t1059.005
logsource:
category: process_creation
product: windows
detection:
selection_script_interpreter:
ParentImage|endswith:
- '\wscript.exe'
- '\cscript.exe'
- '\mshta.exe'
Image|endswith:
- '\cmd.exe'
- '\powershell.exe'
- '\rundll32.exe'
selection_susp_cli:
CommandLine|contains:
- 'http'
- 'downloadstring'
- 'downloadfile'
- 'regsvr32'
- 'mshta'
- 'wscript'
- 'cscript'
- 'powershell'
- 'cmd.exe'
filter_legitimate_sysadmin:
ParentCommandLine|contains:
- '\\Windows\\System32\\cscript.exe'
CommandLine|contains:
- 'C:\\Windows\\System32\\'
condition: selection_script_interpreter and selection_susp_cli and not filter_legitimate_sysadmin
falsepositives:
- Legitimate system administration scripts that use cscript.exe to spawn cmd.exe for system tasks.
- Custom enterprise software using wscript.exe to launch PowerShell for configuration.
level: high
Sigma is the open, vendor-neutral format for log-based detections. One rule, written once, converts to Splunk SPL, Elastic ES|QL, KQL for Microsoft Sentinel, Sumo, Chronicle, QRadar, and more. Detection engineers love it for the same reason ATT&CK is the lingua franca for tactics — Sigma is the lingua franca for the queries that detect them.
You've got a fresh write-up of a TTP and need a starting detection in your stack today. Generate, tune, ship.
Pair-program with SARA: the generator produces the skeleton, the engineer learns by tuning, the team commits the result.
You have a rule in one query language; describe it in English and get the Sigma version + conversions to every other backend.
Sketch a detection idea in 30 seconds before investing in a full DE sprint.
SARA Open ships an OpenAI-compatible API. Call POST /api/v1/sigma — Plain English in, valid Sigma YAML out, with MITRE tags and false-positive guidance.
curl -X POST https://sara-open.sirp.io/api/v1/sigma \
-H "Authorization: Bearer $SARA_API_KEY" \
-H "Content-Type: application/json" \
-d '{"description": "PowerShell encoded command from Office"}'
Read the API reference →