ET MALWARE Ransomware Locky CnC Beacon 4 21 May

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;
)