alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE BITTERBUG Checkin 2"; flow:to_server,established; http.method; content:"POST"; nocase; http.uri; content:"/vtris"; fast_pattern; content:".php?srs="; pcre:"/\/vtris\d?\.php\?srs=\d{1,10}$/"; http.header_names; content:!"User-Agent|0d 0a|"; reference:md5,34c7f12b4e8f2b81143453af12442ee0; reference:md5,48bbae6ee277b5693b40ecf51919d3a6; classtype:command-and-control; sid:2018901; rev:4; metadata:created_at 2014_08_06, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_09_25;)