Suspicious Execution from a Mounted Device

Last updated 5 months ago on 2025-03-20
Created 4 years ago on 2021-05-28

About

Identifies when a script interpreter or signed binary is launched via a non-standard working directory. An attacker may use this technique to evade defenses.
Tags
Domain: EndpointOS: WindowsUse Case: Threat DetectionTactic: Defense EvasionTactic: ExecutionData Source: Elastic DefendData Source: SysmonLanguage: eql
Severity
medium
Risk Score
47
MITRE ATT&CK™

Defense Evasion (TA0005)(opens in a new tab or window)

Execution (TA0002)(opens in a new tab or window)

License
Elastic License v2(opens in a new tab or window)

Definition

Rule Type
Event Correlation Rule
Integration Pack
Prebuilt Security Detection Rules
Index Patterns
winlogbeat-*logs-endpoint.events.process-*logs-windows.sysmon_operational-*
Related Integrations

endpoint(opens in a new tab or window)

windows(opens in a new tab or window)

Query
process where host.os.type == "windows" and event.type == "start" and process.executable : "C:\\*" and
  (process.working_directory : "?:\\" and not process.working_directory: "C:\\") and
  process.parent.name : "explorer.exe" and
  process.name : ("rundll32.exe", "mshta.exe", "powershell.exe", "pwsh.exe", "cmd.exe", "regsvr32.exe",
                  "cscript.exe", "wscript.exe")

Install detection rules in Elastic Security

Detect Suspicious Execution from a Mounted Device in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(opens in a new tab or window).