This detection rule focuses on identifying HTTP requests that come with an empty User-Agent string in proxy logs. The absence of a User-Agent can be suspicious because most legitimate web requests will have this header present. An empty User-Agent might indicate the use of uncommon request methods or potentially malicious activity, as attackers often manipulate or omit this information to disguise their requests. The rule specifically checks for occurrences where the 'c-useragent' field is empty, helping to flag these unusual patterns in traffic. By monitoring and alerting on such activities, organizations can enhance their security posture by quickly responding to potentially harmful requests that may attempt to exfiltrate data or gain unauthorized access. The rule is categorized as medium-level severity, suggesting that while not all such requests are malicious, they warrant investigation due to the association with certain attack techniques.