Techniques
Sample rules
Unusually Long Command Line
- source: splunk
- technicques:
Description
The following analytic detects unusually long command lines, which may indicate malicious activity. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on the length of command lines executed on hosts. This behavior is significant because attackers often use obfuscated or complex command lines to evade detection and execute malicious payloads. If confirmed malicious, this activity could lead to data theft, ransomware deployment, or further system compromise. Analysts should investigate the source and content of the command line, inspect relevant artifacts, and review concurrent processes to identify potential threats.
Detection logic
| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
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 processlen=len(process)
| eventstats stdev(processlen) as stdev, avg(processlen) as avg
BY dest
| stats max(processlen) as maxlen, values(stdev) as stdevperhost, values(avg) as avgperhost
BY dest, user, process_name,
process
| eval threshold = 3
| where maxlen > ((threshold*stdevperhost) + avgperhost)
| `unusually_long_command_line_filter`