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; content:!"Accept"; content:!"User-Agent|0d 0a|"; content:!"Referer"; reference:md5,92ecb8cedb226a27e354b45a56f0353f; classtype:trojan-activity; sid:2021922; rev:4; metadata:created_at 2015_10_07, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_10_05;)