--- title: "Unusually Long Command Line" excerpt: "" categories: - Endpoint last_modified_at: 2020-12-08 toc: true toc_label: "" tags: - Splunk Enterprise - Splunk Enterprise Security - Splunk Cloud --- ### WARNING THIS IS A EXPERIMENTAL object We have not been able to test, simulate, or build datasets for this object. Use at your own risk. This analytic is **NOT** supported. [Try in Splunk Security Cloud](https://www.splunk.com/en_us/cyber-security.html){: .btn .btn--success} #### Description Command lines that are extremely long may be indicative of malicious activity on your hosts. - **Type**: [Anomaly](https://github.com/splunk/security_content/wiki/object-Analytic-Types) - **Product**: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud - **Datamodel**: - **Last Updated**: 2020-12-08 - **Author**: David Dorsey, Splunk - **ID**: c77162d3-f93c-45cc-80c8-22f6a4264e7f #### Search ``` | tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes by Processes.user Processes.dest Processes.process_name Processes.process | `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 | `unusually_long_command_line_filter` |eval threshold = 3 | where maxlen > ((threshold*stdevperhost) + avgperhost) ``` #### Macros The SPL above uses the following Macros: * [security_content_ctime](https://github.com/splunk/security_content/blob/develop/macros/security_content_ctime.yml) * [security_content_summariesonly](https://github.com/splunk/security_content/blob/develop/macros/security_content_summariesonly.yml) Note that `unusually_long_command_line_filter` is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL. #### Required field * _time * Processes.user * Processes.dest * Processes.process_name * Processes.process #### How To Implement You must be ingesting endpoint data that tracks process activity, including parent-child relationships, from your endpoints to populate the Endpoint data model in the Processes node. The command-line arguments are mapped to the process field in the Endpoint data model. #### Known False Positives Some legitimate applications start with long command lines. #### Associated Analytic story * [Suspicious Command-Line Executions](/stories/suspicious_command-line_executions) * [Unusual Processes](/stories/unusual_processes) * [Possible Backdoor Activity Associated With MUDCARP Espionage Campaigns](/stories/possible_backdoor_activity_associated_with_mudcarp_espionage_campaigns) * [Ransomware](/stories/ransomware) #### Kill Chain Phase * Actions on Objectives #### RBA | Risk Score | Impact | Confidence | Message | | ----------- | ----------- |--------------|--------------| | 42.0 | 70 | 60 | Unusually long command line $Processes.process_name$ on $dest$ | #### Reference #### Test Dataset Replay any dataset to Splunk Enterprise by using our [`replay.py`](https://github.com/splunk/attack_data#using-replaypy) tool or the [UI](https://github.com/splunk/attack_data#using-ui). Alternatively you can replay a dataset into a [Splunk Attack Range](https://github.com/splunk/attack_range#replay-dumps-into-attack-range-splunk-server) * [https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1036.003/atomic_red_team/windows-sysmon.log](https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1036.003/atomic_red_team/windows-sysmon.log) [*source*](https://github.com/splunk/security_content/tree/develop/detections/experimental/endpoint/unusually_long_command_line.yml) \| *version*: **5**