ET MALWARE Corebot Checkin

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Corebot Checkin";
    flow:to_server,established;
    http.method;
    content:"POST";
    http.user_agent;
    content:"Mozilla/5.0 (compatible|3b 20|MSIE 10.0|3b 20|Windows NT 6.1|3b 20|WOW64|3b 20|Trident/6.0)"; startswith;
    http.request_body;
    content:"AQAAA"; fast_pattern; depth:5;
    http.header_names;
    content:!"Accept";
    content:!"Referer|0d 0a|";
    content:!"Content-Type|0d 0a|";
    reference:md5,0f6a9b15bd9fd719bb96491e16eb2f9c;
    reference:url,securityintelligence.com/watch-out-for-corebot-new-stealer-in-the-wild/;
    classtype:command-and-control;
    sid:2021739; rev:3;
    metadata:created_at 2015_08_31, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_06_01;
)