mirror of
https://github.com/splunk/security_content
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Gowthamaraj rajendran
77 lines
3.4 KiB
YAML
77 lines
3.4 KiB
YAML
name: Linux Setuid Using Chmod Utility
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id: bf0304b6-6250-11ec-9d7c-acde48001122
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version: 1
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date: '2021-12-21'
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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: This analytic looks for suspicious chmod utility execution to enable
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SUID bit. This allows a user to temporarily gain root access, usually in order to
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run a program. For example, only the root account is allowed to change the password
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information contained in the password database; If the SUID bit appears as an s,
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the file's owner also has execute permission to the file; if it appears as an S,
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the file's owner does not have execute permission. The second specialty permission
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is the SGID, or set group id bit. It is similar to the SUID bit, except it can temporarily
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change group membership, usually to execute a program. The SGID bit is set if an
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s or an S appears in the group section of permissions.
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data_source:
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- Sysmon Event ID 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 = chmod
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OR Processes.process = "*chmod *") AND Processes.process IN("* g+s *", "* u+s *",
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"* 4777 *", "* 4577 *") by Processes.dest Processes.user Processes.parent_process_name
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Processes.process_name Processes.process Processes.process_id Processes.parent_process_id
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Processes.process_guid | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)`
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| `security_content_ctime(lastTime)` | `linux_setuid_using_chmod_utility_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://www.hackingarticles.in/linux-privilege-escalation-using-capabilities/
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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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- Linux Living Off The Land
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asset_type: Endpoint
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confidence: 70
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impact: 70
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message: a commandline $process$ that may set suid or sgid on $dest$
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mitre_attack_id:
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- T1548.001
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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: 49
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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: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1548.001/chmod_uid/sysmon_linux.log
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source: Syslog:Linux-Sysmon/Operational
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sourcetype: sysmon_linux
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