mirror of
https://github.com/splunk/security_content
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Michael Haag
86 lines
4.3 KiB
YAML
86 lines
4.3 KiB
YAML
name: Linux SSH Remote Services Script Execute
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id: aa1748dd-4a5c-457a-9cf6-ca7b4eb711b3
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version: 9
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date: '2025-10-14'
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author: Michael Haag, Splunk
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status: production
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type: TTP
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description: The following analytic detects the use of SSH to move laterally and execute
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a script or file on a remote host. It leverages data from Endpoint Detection and
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Response (EDR) agents, focusing on specific SSH command-line parameters and URLs.
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This activity is significant as it may indicate an attacker attempting to execute
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remote commands or scripts, potentially leading to unauthorized access or control
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over additional systems. If confirmed malicious, this could result in lateral movement,
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privilege escalation, or the execution of malicious payloads, compromising the security
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of the network.
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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=ssh
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Processes.process IN ("*oStrictHostKeyChecking*", "*oConnectTimeout*", "*oBatchMode*")
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AND Processes.process IN ("*http:*","*https:*") by Processes.action Processes.dest
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Processes.original_file_name Processes.parent_process Processes.parent_process_exec
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Processes.parent_process_guid Processes.parent_process_id Processes.parent_process_name
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Processes.parent_process_path Processes.process Processes.process_exec Processes.process_guid
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Processes.process_hash Processes.process_id Processes.process_integrity_level Processes.process_name
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Processes.process_path Processes.user Processes.user_id Processes.vendor_product
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| `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
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| `linux_ssh_remote_services_script_execute_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: This is not a common command to be executed. Filter as needed.
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references:
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- https://redcanary.com/blog/lateral-movement-with-secure-shell/
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drilldown_searches:
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- name: View the detection results for - "$user$" and "$dest$"
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search: '%original_detection_search% | search user = "$user$" 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 - "$user$" and "$dest$"
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search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$",
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"$dest$") starthoursago=168 | stats count min(_time) as firstTime max(_time)
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as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk
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Message" values(analyticstories) as "Analytic Stories" values(annotations._all)
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as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics"
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by normalized_risk_object | `security_content_ctime(firstTime)` | `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: An instance of $process_name$ was identified on endpoint $dest$ by user
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$user$ attempting to move laterally and download a file.
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risk_objects:
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- field: user
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type: user
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score: 56
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- field: dest
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type: system
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score: 56
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threat_objects:
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- field: process_name
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type: process_name
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tags:
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analytic_story:
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- Linux Living Off The Land
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- Hellcat Ransomware
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asset_type: Endpoint
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mitre_attack_id:
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- T1021.004
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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: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1021.004/atomic_red_team/linux-sysmon.log
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source: Syslog:Linux-Sysmon/Operational
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sourcetype: sysmon:linux
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