Conhost Spawned By Suspicious Parent Process

Detects when the Console Window Host (conhost.exe) process is spawned by a suspicious parent process, which could be indicative of code injection.

Rule type: eql

Rule indices:

winlogbeat-*
logs-endpoint.events.*
logs-windows.*

Severity: high

Risk score: 73

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

https://www.fireeye.com/blog/threat-research/2017/08/monitoring-windows-console-activity-part-one.html

Tags:

Elastic
Host
Windows
Threat Detection
Execution

Version: 5

Rule authors:

Elastic

Rule license: Elastic License v2

Investigation guide

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## Config

If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define `event.ingested` and default fallback for EQL rules was not added until 8.2, so you will need to add a custom pipeline to populate `event.ingested` to @timestamp for this rule to work.

Rule query

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process where event.type in ("start", "process_started") and
  process.name : "conhost.exe" and
  process.parent.name : ("svchost.exe", "lsass.exe", "services.exe", "smss.exe", "winlogon.exe", "explorer.exe",
                         "dllhost.exe", "rundll32.exe", "regsvr32.exe", "userinit.exe", "wininit.exe", "spoolsv.exe",
                         "wermgr.exe", "csrss.exe", "ctfmon.exe")

Framework: MITRE ATT&CK^TM

Tactic:
- Name: Execution
- ID: TA0002
- Reference URL: https://attack.mitre.org/tactics/TA0002/
Technique:
- Name: Command and Scripting Interpreter
- ID: T1059
- Reference URL: https://attack.mitre.org/techniques/T1059/

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