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Description

The following analytic detects suspicious file copy operations from the System32 or SysWow64 directories, often indicative of malicious activity. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on processes initiated by command-line tools like cmd.exe or PowerShell. This behavior is significant as it may indicate an attempt to execute malicious code using legitimate system tools (LOLBIN). If confirmed malicious, this activity could allow an attacker to execute arbitrary code, potentially leading to system compromise or further lateral movement within the network.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2024-05-16
  • Author: Teoderick Contreras, Splunk
  • ID: ce633e56-25b2-11ec-9e76-acde48001122

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1036.003 Rename System Utilities Defense Evasion
T1036 Masquerading Defense Evasion
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.parent_process_name IN("cmd.exe", "powershell*","pwsh.exe", "sqlps.exe", "sqltoolsps.exe", "powershell_ise.exe") AND `process_copy` AND Processes.process IN("*\\Windows\\System32\\*", "*\\Windows\\SysWow64\\*") AND Processes.process = "*copy*" by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process Processes.process_id Processes.parent_process_id temp 
| `drop_dm_object_name(Processes)` 
| eval splitted_commandline=split(process," ") 
| eval first_cmdline=lower(mvindex(splitted_commandline,0)) 
| where NOT LIKE(first_cmdline,"%\\windows\\system32\\%") AND NOT LIKE(first_cmdline,"%\\windows\\syswow64\\%") 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
|`suspicious_copy_on_system32_filter`

Macros

The SPL above uses the following Macros:

:information_source: suspicious_copy_on_system32_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • Processes.dest
  • Processes.user
  • Processes.parent_process_name
  • Processes.parent_process
  • Processes.original_file_name
  • Processes.process_name
  • Processes.process
  • Processes.process_id
  • Processes.parent_process_path
  • Processes.process_path
  • Processes.parent_process_id

How To Implement

The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the Processes node of the Endpoint data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.

Known False Positives

every user may do this event but very un-ussual.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
63.0 70 90 Execution of copy exe to copy file from $process$ in $dest$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

source | version: 2