LoFP / some legitimate system processes, software updaters, or compatibility tools may trigger this behavior, occurrences involving unknown, unsigned, or unusual parent processes should be investigated for potential malware activity, persistence mechanisms, or execution flow hijacking.

Techniques

• T1036.009

Sample rules

Windows Unusual SysWOW64 Process Run System32 Executable

• source: splunk
• technicques:
  • T1036.009

Description

The following analytic detects an unusual process execution pattern where a process running from C:\Windows\SysWOW64\ attempts to execute a binary from C:\Windows\System32. In a typical Windows environment, 32-bit processes under SysWOW64 should primarily interact with 32-bit binaries within the same directory. However, an execution flow where a 32-bit process spawns a 64-bit binary from System32 can indicate potential process injection, privilege escalation, evasion techniques, or unauthorized execution hijacking.

Detection logic

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where Processes.process_path = "*\\Windows\\SysWOW64\\*" AND Processes.process = "*windows\\system32\\*" by Processes.parent_process_name Processes.process_path Processes.process Processes.original_file_name Processes.dest Processes.user 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_unusual_syswow64_process_run_system32_executable_filter`