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https://github.com/splunk/security_content
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pyth0n1c
73 lines
3.3 KiB
YAML
73 lines
3.3 KiB
YAML
name: Linux Sudoers Tmp File Creation
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id: be254a5c-63e7-11ec-89da-acde48001122
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version: 6
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date: '2025-02-10'
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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 creation of the "sudoers.tmp" file,
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which occurs when editing the /etc/sudoers file using visudo or another editor on
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a Linux platform. This detection leverages filesystem data to identify the presence
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of "sudoers.tmp" files. Monitoring this activity is crucial as adversaries may exploit
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it to gain elevated privileges on a compromised host. If confirmed malicious, this
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activity could allow attackers to modify sudoers configurations, potentially granting
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them unauthorized access to execute commands as other users, including root, thereby
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compromising the system's security.
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data_source:
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- Sysmon for Linux EventID 11
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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.Filesystem where Filesystem.file_path IN ("*sudoers.tmp*")
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by Filesystem.dest Filesystem.file_name Filesystem.process_guid Filesystem.file_path
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| `drop_dm_object_name(Filesystem)` | `security_content_ctime(lastTime)` | `security_content_ctime(firstTime)`
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| `linux_sudoers_tmp_file_creation_filter`'
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how_to_implement: To successfully implement this search, you need to be ingesting
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logs with the process name, parent process, and command-line executions from your
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endpoints. If you are using Sysmon, you can use the Add-on for Linux Sysmon from
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Splunkbase.
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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://forum.ubuntuusers.de/topic/sudo-visudo-gibt-etc-sudoers-tmp/
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drilldown_searches:
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- name: View the detection results for - "$dest$"
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search: '%original_detection_search% | search dest = "$dest$"'
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earliest_offset: $info_min_time$
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latest_offset: $info_max_time$
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- name: View risk events for the last 7 days for - "$dest$"
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search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$")
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starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime
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values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories)
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as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic)
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as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)`
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| `security_content_ctime(lastTime)`'
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earliest_offset: $info_min_time$
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latest_offset: $info_max_time$
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rba:
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message: A file $file_name$ is created in $file_path$ on $dest$
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risk_objects:
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- field: dest
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type: system
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score: 72
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threat_objects: []
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tags:
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analytic_story:
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- Linux Privilege Escalation
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- Earth Estries
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- Nexus APT Threat Activity
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- Linux Persistence Techniques
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asset_type: Endpoint
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mitre_attack_id:
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- T1548.003
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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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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/sudoers_temp/sysmon_linux.log
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source: Syslog:Linux-Sysmon/Operational
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sourcetype: sysmon:linux
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