Detection: Windows Script Host Spawn MSBuild

Description

This analytic is to detect a suspicious child process of MSBuild spawned by Windows Script Host - cscript or wscript. This behavior or event are commonly seen and used by malware or adversaries to execute malicious msbuild process using malicious script in the compromised host. During triage, review parallel processes and identify any file modifications. MSBuild may load a script from the same path without having command-line arguments.

Annotations

No annotations available.

Implementation

To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the Endpoint datamodel in the Processes node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.

Known False Positives

False positives should be limited as developers do not spawn MSBuild via a WSH.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message Risk Score Impact Confidence
An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest_device_id$ by user $dest_user_id$. 80 80 100
The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

References


Version: 4