ET MALWARE Win32/RCAP CnC Checkin

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Win32/RCAP CnC Checkin";
    flow:established,to_server;
    http.method;
    content:"GET";
    http.uri;
    content:"/callback.php?k="; fast_pattern;
    content:"&x="; distance:0;
    http.connection;
    content:"close"; bsize:5;
    http.header_names;
    content:!"Referer|0d 0a|";
    reference:md5,3410af519f791af5f9554cbff7ece24a;
    classtype:command-and-control;
    sid:2024984; rev:3;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_11_14, deployment Perimeter, malware_family Win32_RCAP, performance_impact Moderate, confidence High, signature_severity Major, updated_at 2020_08_17;
)