alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET MALWARE Ransomware Locky CnC Beacon 4 21 May"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/access.cgi"; fast_pattern; http.header; content:"www-form-urlencoded|0d 0a|"; content:"User-Agent|3a|"; http.request_body; pcre:"/[\x80-\xff]/"; http.header_names; content:!"Referer|0d 0a|"; content:!"Accept"; reference:md5,53859b74ab0ed0e98065982462f4e575; classtype:command-and-control; sid:2022844; rev:3; metadata:attack_target Client_Endpoint, created_at 2016_05_31, deployment Perimeter, signature_severity Major, tag c2, updated_at 2020_07_14, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;)