alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Backdoor.Elise CnC Beacon 3 M2"; flow:to_server,established; http.method; content:"GET"; http.uri; content:".html"; nocase; endswith; pcre:"/\/\d{8,10}\.html$/i"; http.cookie; content:"BX="; http.start; content:"Cookie|3a 20|XX="; fast_pattern; http.header_names; content:!"Referer|0d 0a|"; reference:md5,cf3f36dd3235d2cff5754b19b9e1cb1f; reference:url,github.com/pan-unit42/iocs/tree/master/lotusblossom; classtype:command-and-control; sid:2021278; rev:7; metadata:attack_target Client_Endpoint, created_at 2015_06_16, deployment Perimeter, signature_severity Major, tag c2, updated_at 2020_11_03, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)