alert http $HTTP_SERVERS any -> $EXTERNAL_NET any (msg:"ET MALWARE VBulletin Backdoor C2 URI Structure"; flow:established,to_server; http.uri; content:"/ss?t=f&"; depth:8; reference:url,blog.sucuri.net/2013/07/vbulletin-infections-from-adabeupdate.html; classtype:command-and-control; sid:2017112; rev:5; metadata:created_at 2013_07_05, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_04_24;)