Try in Splunk Security Cloud

Description

The following analytic identifies a unix shell command that can wipe root folders of a linux host. This commandline is being abused by Awfulshred malware that wipes or corrupts files in a targeted Linux host. The shell command uses the rm command with force recursive deletion even in the root folder. This TTP can be a good indicator that a user or a process wants to wipe roots directory files in Linux host.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2023-02-08
  • Author: Teoderick Contreras, Splunk
  • ID: b11d3979-b2f7-411b-bb1a-bd00e642173b

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1485 Data Destruction Impact
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 3
  • CIS 5
  • CIS 16
CVE 


1
2
3
4
5



| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_name = "rm"  AND Processes.process IN ("* -rf*", "* -fr*") AND Processes.process = "* --no-preserve-root" by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process Processes.process_id Processes.parent_process_id Processes.process_guid 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `linux_data_destruction_command_filter`

Macros

The SPL above uses the following Macros:

:information_source: linux_data_destruction_command_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.

  • _time
  • Processes.dest
  • Processes.user
  • Processes.parent_process_name
  • Processes.process_name
  • Processes.process
  • Processes.process_id
  • Processes.parent_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 can use the Add-on for Linux Sysmon from Splunkbase.

Known False Positives

unknown

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
90.0 100 90 a $process_name$ execute rm command with –no-preserve-root parmeter that can wipe root files in $dest$

: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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