mirror of
https://github.com/splunk/security_content
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Gowthamaraj rajendran
82 lines
3.5 KiB
YAML
82 lines
3.5 KiB
YAML
name: PowerShell Start-BitsTransfer
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id: 39e2605a-90d8-11eb-899e-acde48001122
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version: 2
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date: '2021-03-29'
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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: Start-BitsTransfer is the PowerShell "version" of BitsAdmin.exe. Similar
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functionality is present. This technique variation is not as commonly used by adversaries,
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but has been abused in the past. Lesser known uses include the ability to set the
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`-TransferType` to `Upload` for exfiltration of files. In an instance where `Upload`
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is used, it is highly possible files will be archived. During triage, review parallel
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processes and process lineage. Capture any files on disk and review. For the remote
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domain or IP, what is the reputation?
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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 `process_powershell` Processes.process=*start-bitstransfer*
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by Processes.dest Processes.user Processes.parent_process Processes.process_name
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Processes.process Processes.process_id Processes.original_file_name Processes.parent_process_id
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| `drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`
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| `powershell_start_bitstransfer_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: Limited false positives. It is possible administrators will
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utilize Start-BitsTransfer for administrative tasks, otherwise filter based parent
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process or command-line arguments.
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references:
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- https://isc.sans.edu/diary/Investigating+Microsoft+BITS+Activity/23281
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- https://docs.microsoft.com/en-us/windows/win32/bits/using-windows-powershell-to-create-bits-transfer-jobs
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tags:
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analytic_story:
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- BITS Jobs
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asset_type: Endpoint
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confidence: 80
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impact: 70
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message: A suspicious process $process_name$ with commandline $process$ that are
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related to bittransfer functionality in host $dest$
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mitre_attack_id:
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- T1197
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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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- name: user
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type: User
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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: 56
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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/T1197/atomic_red_team/windows-sysmon.log
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source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
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sourcetype: xmlwineventlog
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