alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE StartPage Userclass HTTP Request"; flow:established,to_server; urilen:10; http.uri; content:"/Userclass"; fast_pattern; http.header_names; to_lowercase; content:!"|0d 0a|accept"; content:!"|0d 0a|user-agent|0d 0a|"; content:!"|0d 0a|referer|0d 0a|"; reference:md5,92ecb8cedb226a27e354b45a56f0353f; classtype:trojan-activity; sid:2021922; rev:5; metadata:created_at 2015_10_07, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_04_21;)