alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Operation SpoofedScholars Activity (GET)"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/connect/?memberemailid="; startswith; fast_pattern; pcre:"/^[A-Z]{2}-[A-Z0-9]{10,20}-[A-Z0-9]{6,10}-[A-Z0-9]{2,8}-[A-Z0-9]{2,8}-[0-9]{2,5}$/R"; http.header_names; content:!"Referer"; classtype:trojan-activity; sid:2033317; rev:1; metadata:attack_target Client_Endpoint, created_at 2021_07_12, deployment Perimeter, deployment SSLDecrypt, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_07_12;)