ET MALWARE Matsnu Checkin

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Matsnu Checkin";
    flow:to_server,established;
    http.method;
    content:"POST"; nocase;
    http.uri;
    content:".php?"; fast_pattern;
    http.user_agent;
    content:"Mozilla/4.0 (compatible|3b 20|MSIE 6.0b|3b 20|Windows NT 5.0|3b 20|.NET CLR 1.0.2914)"; bsize:70;
    http.request_body;
    content:"="; depth:7;
    content:"AA"; distance:3; within:2;
    pcre:"/^[a-z]{1,7}=(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=|[A-Za-z0-9+/]{4})$/";
    http.connection;
    content:"Keep-AliveCache-Control|3a 20|no-cache"; bsize:33;
    http.header_names;
    content:!"Referer|0d 0a|";
    reference:md5,7ff6912828faedbf39c4c66c7ba0260d;
    reference:md5,0361c2685bf799c04d796a6d18e1f075;
    reference:url,blog.checkpoint.com/wp-content/uploads/2015/07/matsnu-malwareid-technical-brief.pdf;
    classtype:command-and-control;
    sid:2021399; rev:6;
    metadata:created_at 2015_07_10, performance_impact Significant, signature_severity Major, updated_at 2024_04_30;
)