alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Databack CnC"; flow:to_server,established; http.method; content:"GET"; http.uri; content:".php?pn="; fast_pattern; content:"&s="; distance:0; content:"&x="; distance:0; pcre:"/\.php\?pn=[^&]+&s=[0-9]+&x=0\.[0-9]{7}$/"; http.header_names; content:!"Referer|0d 0a|"; reference:md5,dc7b0c078482b68c1ff89da3ac88949b; classtype:command-and-control; sid:2021189; rev:4; metadata:created_at 2015_06_05, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_05_22;)