alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE W32/HelloBridge.Backdoor Register CnC Beacon"; flow:established,to_server; urilen:55; http.uri; content:"/el/sregister.php?name="; fast_pattern; pcre:"/^\x2Fel\x2Fsregister\x2Ephp\x3Fname\x3D[a-f0-9]{32}$/"; reference:url,www.secureworks.com/resources/blog/research/hellobridge-trojan-uses-heartbleed-news-to-lure-victims/; classtype:command-and-control; sid:2018474; rev:4; metadata:attack_target Client_Endpoint, created_at 2014_05_14, deployment Perimeter, signature_severity Major, tag c2, updated_at 2020_09_24, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)