Linux RPM Privilege Escalation

Original Source: [splunk source]
Name:Linux RPM Privilege Escalation
id:f8e58a23-cecd-495f-9c65-6c76b4cb9774
version:4
date:2024-09-30
author:Gowthamaraj Rajendran, Splunk
status:production
type:Anomaly
Description:The following analytic detects the execution of the RPM Package Manager with elevated privileges, specifically when it is used to run system commands as root via the `--eval` and `lua:os.execute` options. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions and process metadata. This activity is significant because it indicates a potential privilege escalation attempt, allowing a user to gain root access. If confirmed malicious, this could lead to full system compromise, unauthorized access to sensitive data, and further exploitation of the environment.
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="*rpm*--eval*" AND Processes.process="*lua:os.execute*" AND Processes.process="*sudo*" 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)`
| `security_content_ctime(lastTime)`
| `linux_rpm_privilege_escalation_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:False positives are present based on automated tooling or system administrative usage. Filter as needed.
References:
  -https://gtfobins.github.io/gtfobins/rpm/
  -https://en.wikipedia.org/wiki/RPM_Package_Manager
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:'$info_max_time$'
tags:
  analytic_story:
    - 'Linux Privilege Escalation'
    - 'Linux Living Off The Land'
  asset_type:Endpoint
  confidence:50
  impact:60
  message:An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$
  mitre_attack_id:
    - 'T1548.003'
    - 'T1548'
  observable:
    name:'dest'
    type:'Hostname'
    - role:
      - 'Victim'
    name:'parent_process_name'
    type:'Process'
    - role:
      - 'Attacker'
    name:'process_name'
    type:'Process'
    - role:
      - 'Attacker'
  product:
    - 'Splunk Enterprise'
    - 'Splunk Enterprise Security'
    - 'Splunk Cloud'
  required_fields:
    - '_time'
    - 'Processes.dest'
    - 'Processes.user'
    - 'Processes.parent_process_name'
    - 'Processes.process_name'
    - 'Processes.process'
    - 'Processes.process_id'
    - 'Processes.parent_process_id'
  risk_score:30
  security_domain:endpoint

tests:
name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1548/rpm/sysmon_linux.log
  source: Syslog:Linux-Sysmon/Operational
  sourcetype: sysmon:linux
  update_timestamp: True
manual_test:None