Unusual Web User Agent
editUnusual Web User Agent
editA machine learning job detected a rare and unusual user agent indicating web browsing activity by an unusual process other than a web browser. This can be due to persistence, command-and-control, or exfiltration activity. Uncommon user agents coming from remote sources to local destinations are often the result of scanners, bots, and web scrapers, which are part of common Internet background traffic. Much of this is noise, but more targeted attacks on websites using tools like Burp or SQLmap can sometimes be discovered by spotting uncommon user agents. Uncommon user agents in traffic from local sources to remote destinations can be any number of things, including harmless programs like weather monitoring or stock-trading programs. However, uncommon user agents from local sources can also be due to malware or scanning activity.
Rule type: machine_learning
Machine learning job: packetbeat_rare_user_agent
Machine learning anomaly threshold: 50
Severity: low
Risk score: 21
Runs every: 15 minutes
Searches indices from: now-45m (Date Math format, see also Additional look-back time
)
Maximum alerts per execution: 100
References:
Tags:
- Elastic
- Network
- Threat Detection
- ML
Version: 3 (version history)
Added (Elastic Stack release): 7.7.0
Last modified (Elastic Stack release): 7.10.0
Rule authors: Elastic
Rule license: Elastic License
Potential false positives
editWeb activity that is uncommon, like security scans, may trigger this alert and may need to be excluded. A new or rarely used program that calls web services may trigger this alert.
Rule version history
edit- Version 3 (7.10.0 release)
-
- Formatting only
- Version 2 (7.9.0 release)
-
- Formatting only