ET MALWARE Locky CnC Checkin Dec 5 M1

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Locky CnC Checkin Dec 5 M1";
    flow:to_server,established;
    urilen:12;
    http.method;
    content:"POST";
    http.uri;
    content:"/checkupdate"; fast_pattern;
    http.header;
    content:"x-requested-with|3a 20|XMLHttpRequest|0d 0a|";
    content:"www-form-urlencoded|0d 0a|";
    http.request_body;
    pcre:"/^(?:[A-Za-z]{1,10}=(?=[A-Za-z0-9_+\x2d\x2e%]*%[A-F0-9]{2}%[A-F0-9]{2}%[A-F0-9]{2})[A-Za-z0-9_+\x2d\x2e%]+&)+(?=[a-z]{0,9}[A-Z])(?=[A-Z]{0,9}[a-z])[A-Za-z]{1,10}=(?=[A-Za-z0-9_+\x2d\x2e%]*%[A-F0-9]{2}%[A-F0-9]{2}%[A-F0-9]{2})[A-Za-z0-9_+\x2d\x2e%]+\s*$/s";
    classtype:command-and-control;
    sid:2023576; rev:6;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2016_12_05, deployment Perimeter, malware_family Locky, performance_impact Low, confidence High, signature_severity Major, updated_at 2020_11_04;
)