Try in Splunk Security Cloud

Description

The following analytic identifies a process attempting to delete its own file path, a behavior often associated with defense evasion techniques. This detection leverages Sysmon EventCode 1 logs, focusing on command lines executed via cmd.exe that include deletion commands. This activity is significant as it may indicate malware, such as Clop ransomware, trying to evade detection by removing its executable file if certain conditions are met. If confirmed malicious, this could allow the attacker to persist undetected, complicating incident response and remediation efforts.

  • Type: TTP

  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2024-05-27
  • Author: Teoderick Contreras
  • ID: f7eda4bc-871c-11eb-b110-acde48001122

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1070 Indicator Removal Defense Evasion
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


1
2
3
4
5
6
7



`sysmon` EventCode=1 CommandLine = "* /c *" CommandLine = "* del*" Image = "*\\cmd.exe" 
| eval result = if(like(process,"%".parent_process."%"), "Found", "Not Found") 
| stats min(_time) as firstTime max(_time) as lastTime count by dest user ParentImage ParentCommandLine Image CommandLine EventCode ProcessID result 
| where result = "Found" 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `process_deleting_its_process_file_path_filter`

Macros

The SPL above uses the following Macros:

:information_source: process_deleting_its_process_file_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.

  • EventCode
  • dest
  • user
  • ParentImage
  • ParentCommandLine
  • Image
  • cmdline
  • ProcessID
  • result
  • _time

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

unknown

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
60.0 60 100 A process $Image$ tries to delete its process path in commandline $CommandLine$ as part of defense evasion in host $dest$ by user $user$

: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: 3