alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Chthonic CnC Beacon 5"; flow:established,to_server; http.method; content:"POST"; http.user_agent; content:"Mozilla/6."; fast_pattern; startswith; http.request_body; pcre:"/^[\x20-\x7e\r\n]{0,20}[^\x20-\x7e\r\n]/"; http.request_line; content:"/ HTTP/1.1"; http.accept; content:"*/*"; depth:3; endswith; http.content_len; content:!"0"; http.header_names; content:"|0d 0a|Accept|0d 0a|User-Agent|0d 0a|Host|0d 0a|Content-Length|0d 0a|Connection|0d 0a|"; depth:56; content:!"Accept-"; content:!"Content-Type"; content:!"Referer|0d 0a|"; reference:md5,97369af278cc004ce390f68ae94013b6; classtype:command-and-control; sid:2020944; rev:7; metadata:attack_target Client_Endpoint, created_at 2015_04_17, deployment Perimeter, signature_severity Major, tag c2, updated_at 2020_10_28, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)