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Description

This detection is to identify a suspicious process that tries to delete the process file path related to its process. This technique is known to be defense evasion once a certain condition of malware is satisfied or not. Clop ransomware use this technique where it will try to delete its process file path using a .bat command if the keyboard layout is not the layout it tries to infect.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2022-02-18
  • 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
CIS20
CVE 


1
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`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 Computer 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
  • Computer
  • user
  • ParentImage
  • ParentCommandLine
  • Image
  • cmdline
  • ProcessID
  • result
  • _time

How To Implement

You must be ingesting data that records process activity from your hosts to populate the Endpoint data model in the Processes node. You must also be ingesting logs with both the process name and command line from your endpoints. The command-line arguments are mapped to the "process" field in the Endpoint data model.

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 $cmdline$ as part of defense evasion in host $Computer$

: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: 2