Techniques
Sample rules
Regsvr32 with Known Silent Switch Cmdline
- source: splunk
- technicques:
- T1218
- T1218.010
Description
The following analytic detects the execution of Regsvr32.exe with the silent switch to load DLLs. This behavior is identified using Endpoint Detection and Response (EDR) telemetry, focusing on command-line executions containing the -s or /s switches. This activity is significant as it is commonly used in malware campaigns, such as IcedID, to stealthily load malicious DLLs. If confirmed malicious, this could allow an attacker to execute arbitrary code, download additional payloads, and potentially compromise the system further. Immediate investigation and endpoint isolation are recommended.
Detection logic
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_regsvr32` by Processes.user Processes.process_name Processes.process Processes.parent_process_name Processes.original_file_name Processes.dest Processes.process_id
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| where match(process,"(?i)[\-
|\/][Ss]{1}")
| `regsvr32_with_known_silent_switch_cmdline_filter`