Techniques
Sample rules
Windows Alternate DataStream - Process Execution
- source: splunk
- technicques:
- T1564.004
Description
The following analytic detects when a process attempts to execute a file from within an NTFS file system alternate data stream. This detection leverages process execution data from sources like Windows process monitoring or Sysmon Event ID 1, focusing on specific processes known for such behavior. This activity is significant because alternate data streams can be used by threat actors to hide malicious code, making it difficult to detect. If confirmed malicious, this could allow an attacker to execute hidden code, potentially leading to unauthorized actions and further compromise of the system.
Detection logic
| tstats count min(_time) as firstTime max(_time) as lastTime values(Processes.process_current_directory) as directory from datamodel=Endpoint.Processes where Processes.parent_process_name != "unknown" Processes.process_name IN ("appvlp.exe","bitsadmin.exe","control.exe","cscript.exe","forfiles.exe","ftp.exe","mavinject.exe","mshta.exe","powershell.exe","powershell_ise.exe","pwsh.exe","regini.exe","regscr32.exe","rundll32.exe","sc.exe","wmic.exe","wscript.exe") by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process Processes.process_id Processes.parent_process_id
| `drop_dm_object_name(Processes)`
| regex process="(\b)\w+(\.\w+)?:\w+(\.\w{2,4})(?!\.)(\b
|\s
|&)"
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_alternate_datastream___process_execution_filter`