ET MALWARE FF-RAT Stage 1 CnC Checkin

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE FF-RAT Stage 1 CnC Checkin";
    flow:to_server,established;
    http.method;
    content:"POST";
    http.uri;
    content:".php?hdr_ctx="; fast_pattern;
    pcre:"/\.php\?hdr_ctx=[0-9]{1,5}_[0-9]{1,5}$/";
    http.user_agent;
    content:"Mozilla/5.0"; endswith;
    http.header_names;
    content:!"Referer|0d 0a|";
    reference:url,www.cylance.com/en_us/blog/breaking-down-ff-rat-malware.html;
    classtype:command-and-control;
    sid:2024419; rev:3;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_06_22, deployment Perimeter, performance_impact Moderate, confidence High, signature_severity Major, updated_at 2020_09_14;
)