ET MALWARE BKDR_SLOTH.A Checkin

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE BKDR_SLOTH.A Checkin";
    flow:established,to_server;
    urilen:10;
    http.method;
    content:"GET";
    http.uri;
    content:"/help.html"; fast_pattern;
    http.user_agent;
    content:"Mozilla/5.0 (compatible|3b 20|MSIE 7.0|3b 20|Windows NT 6.0)";
    http.header_names;
    content:!"Accept|0d 0a|";
    content:!"Referer|0d 0a|";
    reference:md5,185e930a19ad1a99c226d59ef563e28c;
    reference:url,blog.trendmicro.com/trendlabs-security-intelligence/the-siesta-campaign-a-new-targeted-attack-awakens/;
    reference:url,fireeye.com/blog/technical/targeted-attack/2014/03/a-detailed-examination-of-the-siesta-campaign.html;
    classtype:command-and-control;
    sid:2018285; rev:6;
    metadata:created_at 2014_03_17, signature_severity Major, updated_at 2020_09_23;
)