mirror of
https://github.com/splunk/security_content
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Gowthamaraj rajendran
92 lines
4.3 KiB
YAML
92 lines
4.3 KiB
YAML
name: Linux At Application Execution
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id: bf0a378e-5f3c-11ec-a6de-acde48001122
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version: 2
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date: '2022-05-26'
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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 "At" application
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in Linux, which can be used by attackers to create persistence entries on a compromised
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host. The "At" application can be used for automation purposes by administrators
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or network operators, so the filter macros should be updated to remove false positives.
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If a true positive is found, it suggests an attacker is trying to maintain access
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to the environment or potentially deliver additional malicious payloads, leading
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to data theft, ransomware, or other damaging outcomes. To implement this analytic,
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ensure you are ingesting logs with the required fields from your endpoints into
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the Endpoint datamodel. When a true positive is detected, it suggests that an attacker
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is attempting to establish persistence or deliver additional malicious payloads
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by leveraging the "At" application. This behavior can lead to data theft, ransomware
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attacks, or other damaging outcomes.\
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During triage, the SOC analyst should review the context surrounding the execution
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of the "At" application. This includes identifying the user, the parent process
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responsible for invoking the application, and the specific command-line arguments
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used. It is important to consider whether the execution is expected behavior by
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an administrator or network operator for legitimate automation purposes.\
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The presence of "At" application execution may indicate an attacker''s attempt to
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maintain unauthorized access to the environment. Immediate investigation and response
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are necessary to mitigate further risks, identify the attacker''s intentions, and
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prevent potential harm to the organization.'
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data_source:
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- Sysmon Event ID 1
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search: '| tstats `security_content_summariesonly` count from datamodel=Endpoint.Processes
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where Processes.process_name IN ("at", "atd") OR Processes.parent_process_name
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IN ("at", "atd") 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_at_application_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 use this application
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for automation purposes. Please update the filter macros to remove false positives.
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references:
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- https://attack.mitre.org/techniques/T1053/001/
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- https://www.linkedin.com/pulse/getting-attacker-ip-address-from-malicious-linux-job-craig-rowland/
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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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- Scheduled Tasks
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asset_type: Endpoint
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confidence: 30
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impact: 30
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message: At application was executed in $dest$
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mitre_attack_id:
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- T1053.002
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- T1053
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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: 9
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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/T1053.002/at_execution/sysmon_linux.log
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source: Syslog:Linux-Sysmon/Operational
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sourcetype: sysmon_linux
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