splApache-2.0from splunk/security_content

Fsutil Zeroing File

The following analytic detects the execution of the 'fsutil' command with the 'setzerodata' parameter, which zeros out a target file. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line arguments. This activity is significant because it is a technique used by ransomware, such as LockBit, to evade detection by erasing its malware path after encrypting the host. If confirmed malicious, this action could hinder forensic investigations and allow attackers to cover their tracks, complicating incident response efforts.

Quality

FP risk

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Forks

Views

Rule sourcedetections/endpoint/fsutil_zeroing_file.yml

| tstats `security_content_summariesonly` count values(Processes.process) as process values(Processes.parent_process) as parent_process min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
  WHERE Processes.process_name=fsutil.exe Processes.process="*setzerodata*"
  BY Processes.action Processes.dest Processes.original_file_name
     Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
     Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
     Processes.process Processes.process_exec Processes.process_guid
     Processes.process_hash Processes.process_id Processes.process_integrity_level
     Processes.process_name Processes.process_path Processes.user
     Processes.user_id Processes.vendor_product
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `fsutil_zeroing_file_filter`