mirror of
https://github.com/splunk/security_content
synced 2026-06-08 17:32:49 +00:00
Bhavin Patel
75 lines
3.2 KiB
YAML
75 lines
3.2 KiB
YAML
name: Linux Visudo Utility Execution
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id: 08c41040-624c-11ec-a71f-acde48001122
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version: 2
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date: '2024-05-27'
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author: Teoderick Contreras, Splunk
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status: production
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type: Anomaly
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description: The following analytic detects the execution of the 'visudo' utility
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to modify the /etc/sudoers file on a Linux system. It leverages data from Endpoint
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Detection and Response (EDR) agents, focusing on process execution logs. This activity
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is significant because unauthorized changes to the /etc/sudoers file can grant elevated
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privileges to users, potentially allowing adversaries to execute commands as root.
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If confirmed malicious, this could lead to full system compromise, privilege escalation,
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and persistent unauthorized access, severely impacting the security posture of the
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affected host.
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data_source:
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- Sysmon for Linux EventID 1
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search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
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as lastTime from datamodel=Endpoint.Processes where Processes.process_name = visudo
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by Processes.dest Processes.user Processes.parent_process_name Processes.process_name
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Processes.process Processes.process_id Processes.parent_process_id Processes.process_guid
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| `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
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| `linux_visudo_utility_execution_filter`'
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how_to_implement: The detection is based on data that originates from Endpoint Detection
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and Response (EDR) agents. These agents are designed to provide security-related
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telemetry from the endpoints where the agent is installed. To implement this search,
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you must ingest logs that contain the process GUID, process name, and parent process.
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Additionally, you must ingest complete command-line executions. These logs must
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be processed using the appropriate Splunk Technology Add-ons that are specific to
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the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint`
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data model. Use the Splunk Common Information Model (CIM) to normalize the field
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names and speed up the data modeling process.
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known_false_positives: Administrator or network operator can execute this command.
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Please update the filter macros to remove false positives.
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references:
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- https://askubuntu.com/questions/334318/sudoers-file-enable-nopasswd-for-user-all-commands
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tags:
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analytic_story:
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- Linux Privilege Escalation
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- Linux Persistence Techniques
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asset_type: Endpoint
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confidence: 40
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impact: 40
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message: A commandline $process$ executed on $dest$
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mitre_attack_id:
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- T1548.003
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- T1548
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observable:
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- name: dest
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type: Hostname
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role:
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- Victim
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product:
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- Splunk Enterprise
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- Splunk Enterprise Security
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- Splunk Cloud
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required_fields:
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- _time
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- Processes.dest
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- Processes.user
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- Processes.parent_process_name
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- Processes.process_name
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- Processes.process
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- Processes.process_id
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- Processes.parent_process_id
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risk_score: 16
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security_domain: endpoint
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tests:
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- name: True Positive Test
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attack_data:
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- data:
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https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1548.003/visudo/sysmon_linux.log
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source: Syslog:Linux-Sysmon/Operational
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sourcetype: sysmon:linux
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