Techniques
Sample rules
Malicious PowerShell Process With Obfuscation Techniques
- source: splunk
- technicques:
- T1059.001
Description
The following analytic detects PowerShell processes launched with command-line arguments indicative of obfuscation techniques. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names, parent processes, and complete command-line executions. This activity is significant because obfuscated PowerShell commands are often used by attackers to evade detection and execute malicious scripts. If confirmed malicious, this activity could lead to unauthorized code execution, privilege escalation, or persistent access within the environment, posing a significant security risk.
Detection logic
| tstats `security_content_summariesonly` count values(Processes.process) as process values(Processes.parent_process) as parent_process min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Processes where `process_powershell` by Processes.action Processes.dest Processes.original_file_name Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| eval num_obfuscation = (mvcount(split(process,"`"))-1) + (mvcount(split(process, "^"))-1) + (mvcount(split(process, "'"))-1)
| `malicious_powershell_process_with_obfuscation_techniques_filter`
| search num_obfuscation > 10