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Description

The following analytic is designed to detect any execution of AutoIt3, a scripting language designed for automating the Windows GUI and general scripting. This includes instances where AutoIt3 has been renamed or otherwise altered in an attempt to evade detection. The analytic works by searching for process names or original file names that match 'autoit3.exe', which is the default executable for AutoIt scripts. This detection is important as AutoIt3 is often used by attackers to automate malicious activities, such as the execution of malware or other unwanted software. False positives may occur with legitimate uses of AutoIt3.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2023-10-31
  • Author: Michael Haag, Splunk
  • ID: 0ecb40d9-492b-4a57-9f87-515dd742794c

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1059 Command and Scripting Interpreter Execution
Kill Chain Phase
  • Installation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


1
2
3
4
5
6



| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name IN ("autoit3.exe", "autoit*.exe") OR Processes.original_file_name IN ("autoit3.exe", "autoit*.exe") by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.original_file_name Processes.process Processes.process_id Processes.parent_process_id 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_autoit3_execution_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_autoit3_execution_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • Processes.dest
  • Processes.user
  • Processes.parent_process_name
  • Processes.process_name
  • Processes.original_file_name
  • Processes.process
  • Processes.process_id
  • Processes.parent_process_id

How To Implement

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

False positives may be present if the application is legitimately used, filter by user or endpoint as needed.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
50.0 50 100 Execution of AutoIt3 detected. The source process is $parent_process_name$ and the destination process is $process_name$ on $dest$ by

: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