mirror of
https://github.com/splunk/security_content
synced 2026-06-08 17:32:49 +00:00
Bhavin Patel
82 lines
4.2 KiB
YAML
82 lines
4.2 KiB
YAML
name: Fsutil Zeroing File
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id: 4e5e024e-fabb-11eb-8b8f-acde48001122
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version: 7
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date: '2025-05-08'
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author: Teoderick Contreras, Splunk
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status: production
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type: TTP
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description: The following analytic detects the execution of the 'fsutil' command
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with the 'setzerodata' parameter, which zeros out a target file. This detection
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leverages data from Endpoint Detection and Response (EDR) agents, focusing on process
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names and command-line arguments. This activity is significant because it is a technique
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used by ransomware, such as LockBit, to evade detection by erasing its malware path
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after encrypting the host. If confirmed malicious, this action could hinder forensic
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investigations and allow attackers to cover their tracks, complicating incident
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response efforts.
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data_source:
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- Sysmon EventID 1
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- Windows Event Log Security 4688
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- CrowdStrike ProcessRollup2
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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 Processes.process_name=fsutil.exe Processes.process="*setzerodata*"
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by Processes.action Processes.dest Processes.original_file_name Processes.parent_process
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Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id
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Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec
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Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level
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Processes.process_name 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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| `fsutil_zeroing_file_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: unknown
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references:
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- https://app.any.run/tasks/e0ac072d-58c9-4f53-8a3b-3e491c7ac5db/
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- https://news.sophos.com/en-us/2020/04/24/lockbit-ransomware-borrows-tricks-to-keep-up-with-revil-and-maze/
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drilldown_searches:
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- name: View the detection results for - "$dest$"
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search: '%original_detection_search% | search 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 - "$dest$"
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search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$")
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starthoursago=168 | stats count min(_time) as firstTime max(_time) as lastTime
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values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories)
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as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic)
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as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)`
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| `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: Possible file data deletion on $dest$ using $process$
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risk_objects:
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- field: dest
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type: system
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score: 54
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threat_objects: []
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tags:
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analytic_story:
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- Ransomware
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- LockBit Ransomware
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asset_type: Endpoint
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mitre_attack_id:
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- T1070
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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/T1070/fsutil_file_zero/windows-sysmon.log
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source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
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sourcetype: XmlWinEventLog
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