LoFP LoFP / limited false positives with the query restricted to specified paths. add more world writeable paths as tuning continues.

Techniques

Sample rules

Suspicious Regsvr32 Register Suspicious Path

Description

Adversaries may abuse Regsvr32.exe to proxy execution of malicious code by using non-standard file extensions to load DLLs. Upon investigating, look for network connections to remote destinations (internal or external). Review additional parrallel processes and child processes for additional activity.

Detection logic


| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_regsvr32` Processes.process IN ("*\\appdata\\*", "*\\programdata\\*","*\\windows\\temp\\*") NOT (Processes.process IN ("*.dll*", "*.ax*", "*.ocx*")) by Processes.dest Processes.user  Processes.parent_process_name Processes.parent_process Processes.process_name Processes.process Processes.original_file_name Processes.process_id Processes.parent_process_id 
| `drop_dm_object_name(Processes)` 
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)` 
| `suspicious_regsvr32_register_suspicious_path_filter`