mirror of
https://github.com/splunk/security_content
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Gowthamaraj rajendran
74 lines
3.0 KiB
YAML
74 lines
3.0 KiB
YAML
name: Malicious PowerShell Process With Obfuscation Techniques
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id: cde75cf6-3c7a-4dd6-af01-27cdb4511fd4
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version: 5
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date: '2023-04-14'
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author: David Dorsey, Splunk
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status: production
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type: TTP
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description: This search looks for PowerShell processes launched with arguments that
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have characters indicative of obfuscation on the command-line.
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data_source:
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- Sysmon Event ID 1
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search: '| tstats `security_content_summariesonly` count values(Processes.process)
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as process values(Processes.parent_process) as parent_process min(_time) as firstTime
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max(_time) as lastTime from datamodel=Endpoint.Processes where `process_powershell`
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by Processes.user Processes.process_name Processes.original_file_name Processes.parent_process_name
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Processes.dest Processes.process | `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)`|
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`security_content_ctime(lastTime)`| eval num_obfuscation = (mvcount(split(process,"`"))-1)
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+ (mvcount(split(process, "^"))-1) + (mvcount(split(process, "''"))-1) | `malicious_powershell_process_with_obfuscation_techniques_filter`
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| search num_obfuscation > 10 '
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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: These characters might be legitimately on the command-line,
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but it is not common.
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references: []
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tags:
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analytic_story:
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- Malicious PowerShell
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- Hermetic Wiper
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- Data Destruction
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asset_type: Endpoint
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confidence: 60
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impact: 70
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message: Powershell.exe running with potential obfuscated arguments on $dest$
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mitre_attack_id:
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- T1059
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- T1059.001
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observable:
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- name: dest
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type: Endpoint
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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.parent_process
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- Processes.original_file_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_path
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- Processes.process_path
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- Processes.parent_process_id
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risk_score: 42
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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/T1059.001/obfuscated_powershell/windows-sysmon.log
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source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
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sourcetype: xmlwineventlog
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