LoFP / limited false positives, however this analytic will need to be modified for each environment if sysmon is not used.

Techniques

• T1560
• T1560.001

Sample rules

Detect Renamed 7-Zip

• source: splunk
• technicques:
  • T1560.001
  • T1560

Description

The following analytic identifies renamed 7-Zip usage using Sysmon. At this stage of an attack, review parallel processes and file modifications for data that is staged or potentially have been exfiltrated. This analytic utilizes the OriginalFileName to capture the renamed process. During triage, validate this is the legitimate version of 7zip by reviewing the PE metadata. In addition, review parallel processes for further suspicious behavior.

Detection logic

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where (Processes.original_file_name=7z*.exe AND Processes.process_name!=7z*.exe) by Processes.dest Processes.user Processes.parent_process_name Processes.process_name Processes.process Processes.process_id Processes.parent_process_id Processes.original_file_name 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `detect_renamed_7_zip_filter`