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Description

This analytic identifies excessive usage of taskkill.exe application. This application is commonly used by adversaries to evade detections by killing security product processes or even other processes to evade detection.

  • Type: Anomaly
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2021-05-04
  • Author: Teoderick Contreras, Splunk
  • ID: fe5bca48-accb-11eb-a67c-acde48001122

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1562.001 Disable or Modify Tools Defense Evasion
T1562 Impair Defenses Defense Evasion
Kill Chain Phase
  • Exploitation
NIST
CIS20
CVE
1
2
3
4
5
6
7
| tstats `security_content_summariesonly` values(Processes.process) as process values(Processes.process_id) as process_id count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name = "taskkill.exe"  by Processes.parent_process_name Processes.process_name Processes.dest Processes.user _time span=1m 
| where count >=10 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `excessive_usage_of_taskkill_filter`

Macros

The SPL above uses the following Macros:

:information_source: excessive_usage_of_taskkill_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Supported Add-on (TA)

List of Splunk Add-on’s tested to work with the analytic.

Required fields

List of fields required to use this analytic.

  • _time
  • Processes.parent_process_name
  • Processes.process_name
  • Processes.dest
  • Processes.user
  • Processes.process
  • Processes.process_id

How To Implement

To successfully implement this search, you need to be ingesting logs with the process name, parent process, and command-line executions from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA. Tune and filter known instances where renamed taskkill.exe may be used.

Known False Positives

Unknown. Filter as needed.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
28.0 40 70 Excessive usage of taskkill.exe with process id $process_id$ (more than 10 within 1m) has been detected on $dest$ with a parent process of $parent_process_name$.

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

source | version: 1