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Description

The following analytic identifies AccCheckConsole.exe which is a native living off the land binary or script (LOLBAS) within the Windows operating system that may be abused by adversaries by moving it to a new directory. The list of binaries was derived from the https://lolbas-project.github.io site.

  • Type: Anomaly
  • Product: Splunk Behavioral Analytics
  • Datamodel: Endpoint_Processes
  • Last Updated: 2022-10-18
  • Author: Splunk Threat Research Bot, Splunk
  • ID: c842931e-661f-42bc-a4df-0460d93cfb69

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1036 Masquerading Defense Evasion
T1036.003 Rename System Utilities Defense Evasion
Kill Chain Phase
  • Actions on Objectives
NIST
  • PR.PT
  • DE.CM
CIS20
  • CIS 8
CVE 


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| from read_ssa_enriched_events() 
| eval device=ucast(map_get(input_event, "dest_device_id"), "string", null), user=ucast(map_get(input_event, "dest_user_id"), "string", null), timestamp=parse_long(ucast(map_get(input_event, "_time"), "string", null)), process_name=lower(ucast(map_get(input_event, "process_name"), "string", null)), process_path=lower(ucast(map_get(input_event, "process_path"), "string", null)), event_id=ucast(map_get(input_event, "event_id"), "string", null)
| where process_name IS NOT NULL AND process_name="acccheckconsole.exe"
| where process_path IS NOT NULL AND match_regex(process_path, /(?i)\\program files (x86)\\windows kits\\10\\bin\\10.0.22000.0\\arm64\\accchecker/)=false 
| eval start_time=timestamp,end_time=timestamp, entities=mvappend(device, user), body=create_map(["event_id", event_id, "process_path", process_path, "process_name", process_name]) 
| into write_ssa_detected_events();

Macros

The SPL above uses the following Macros:

:information_source: windows_rename_system_utilities_acccheckconsole_exe_lolbas_in_non_standard_path_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.

  • dest_device_id
  • process_name
  • _time
  • dest_user_id
  • process_path

How To Implement

To successfully implement this search, you must be ingesting logs with the process name, command-line arguments, and parent processes from your endpoints. Collect endpoint data such as Sysmon or Windows Events 4688.

Known False Positives

False positives may be present and filtering may be required. Certain utilities will run from non-standard paths based on the third-party application in use.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
14.0 20 70 A system process $process_name$ with path $process_path$ spawn in non-default folder path on host $dest_device_id$

: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

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