Linux apt-get Privilege Escalation

Original Source: [splunk source]
Name:Linux apt-get Privilege Escalation
id:d870ce3b-e796-402f-b2af-cab4da1223f2
version:4
date:2024-09-30
author:Gowthamaraj Rajendran, Splunk
status:production
type:Anomaly
Description:The following analytic detects the execution of the 'apt-get' command with elevated privileges using 'sudo' on a Linux system. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process execution logs that include command-line details. This activity is significant because it indicates a user may be attempting to escalate privileges to root, which could lead to unauthorized system control. If confirmed malicious, an attacker could gain root access, allowing them to execute arbitrary commands, install or remove software, and potentially compromise the entire system.
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="*apt-get*" AND Processes.process="*APT::Update::Pre-Invoke::*" 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_apt_get_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 may be present, filter as needed.
References:
  -https://gtfobins.github.io/gtfobins/apt-get/
  -https://phoenixnap.com/kb/how-to-use-apt-get-commands
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:20
  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:10
  security_domain:endpoint

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