mirror of
https://github.com/splunk/security_content
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Bhavin Patel
92 lines
3.7 KiB
YAML
92 lines
3.7 KiB
YAML
name: Winword Spawning PowerShell
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id: b2c950b8-9be2-11eb-8658-acde48001122
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version: 3
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date: '2024-05-10'
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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 identifies instances where Microsoft Word (winword.exe)
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spawns a PowerShell process. This behavior is detected using Endpoint Detection
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and Response (EDR) telemetry, focusing on process creation events where the parent
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process is winword.exe. This activity is significant because it is uncommon and
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often associated with spearphishing attacks, where malicious documents execute encoded
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PowerShell commands. If confirmed malicious, this could allow an attacker to execute
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arbitrary code, potentially leading to data exfiltration, system compromise, or
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further lateral movement within the network.
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data_source:
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- Sysmon 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.parent_process_name="winword.exe"
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`process_powershell` by Processes.dest Processes.user Processes.parent_process_name
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Processes.parent_process Processes.process_name Processes.original_file_name Processes.process
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Processes.process_id Processes.parent_process_id | `drop_dm_object_name(Processes)`
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| `security_content_ctime(firstTime)`| `security_content_ctime(lastTime)` | `winword_spawning_powershell_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: False positives should be limited, but if any are present,
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filter as needed.
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references:
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- https://redcanary.com/threat-detection-report/techniques/powershell/
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- https://attack.mitre.org/techniques/T1566/001/
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- https://app.any.run/tasks/b79fa381-f35c-4b3e-8d02-507e7ee7342f/
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- https://app.any.run/tasks/181ac90b-0898-4631-8701-b778a30610ad/
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tags:
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analytic_story:
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- Spearphishing Attachments
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- DarkCrystal RAT
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- CVE-2023-21716 Word RTF Heap Corruption
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asset_type: Endpoint
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confidence: 100
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impact: 70
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message: '$parent_process_name$ on $dest$ by $user$ launched the following powershell
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process: $process_name$ which is very common in spearphishing attacks'
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mitre_attack_id:
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- T1566
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- T1566.001
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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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- name: user
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type: User
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role:
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- Victim
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- name: process_name
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type: Process
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role:
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- Target
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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: 70
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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/T1566.001/macro/windows-sysmon.log
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source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
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sourcetype: xmlwineventlog
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