Files
splunk-security_content/detections/endpoint/linux_shred_overwrite_command.yml
pyth0n1c fdaa038eab Finish removing extra fields, or renaming
misnamed fields, in endpoint detections
2025-01-03 15:47:32 -08:00

81 lines
3.9 KiB
YAML

name: Linux Shred Overwrite Command
id: c1952cf1-643c-4965-82de-11c067cbae76
version: 4
date: '2024-11-13'
author: Teoderick Contreras, Splunk
status: production
type: TTP
description: The following analytic detects the execution of the 'shred' command on
a Linux machine, which is used to overwrite files to make them unrecoverable. It
leverages data from Endpoint Detection and Response (EDR) agents, focusing on process
names and command-line arguments. This activity is significant because the 'shred'
command can be used in destructive attacks, such as those seen in the Industroyer2
malware targeting energy facilities. If confirmed malicious, this activity could
lead to the permanent destruction of critical files, severely impacting system integrity
and data availability.
data_source:
- Sysmon for Linux EventID 1
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
as lastTime from datamodel=Endpoint.Processes where Processes.process_name =shred
AND Processes.process IN ("*-n*", "*-u*", "*-z*", "*-s*") by Processes.parent_process_name
Processes.process_name Processes.process Processes.process_id Processes.parent_process_id
Processes.process_guid Processes.dest Processes.user | `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `linux_shred_overwrite_command_filter`'
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: Administrator or network operator can use this application
for automation purposes. Please update the filter macros to remove false positives.
references:
- https://www.welivesecurity.com/2022/04/12/industroyer2-industroyer-reloaded/
- https://cert.gov.ua/article/39518
drilldown_searches:
- name: View the detection results for - "$dest$"
search: '%original_detection_search% | search dest = "$dest$"'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
- name: View risk events for the last 7 days for - "$dest$"
search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$")
starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime
values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories)
as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic)
as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
rba:
message: A possible shred overwrite command $process$ executed on $dest$
risk_objects:
- field: dest
type: system
score: 49
threat_objects: []
tags:
analytic_story:
- Industroyer2
- AwfulShred
- Linux Privilege Escalation
- Data Destruction
- Linux Persistence Techniques
asset_type: Endpoint
mitre_attack_id:
- T1485
product:
- Splunk Enterprise
- Splunk Enterprise Security
- Splunk Cloud
security_domain: endpoint
tests:
- name: True Positive Test
attack_data:
- data:
https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1485/rm_shred_critical_dir/sysmon_linux.log
source: Syslog:Linux-Sysmon/Operational
sourcetype: sysmon:linux