ET MALWARE Red Leaves HTTP CnC Beacon (APT10 implant)

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Red Leaves HTTP CnC Beacon (APT10 implant)";
    flow:established,to_server;
    threshold:type limit, track by_src, count 1, seconds 600;
    http.method;
    content:"POST";
    http.uri;
    content:"/index.php"; endswith;
    http.host;
    pcre:"/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}(?:\x3a\d{1,5})?$/";
    http.request_body;
    pcre:"/^[\x20-\x7e\r\n]{0,28}[^\x20-\x7e\r\n]/s";
    http.accept;
    content:"*/*"; depth:3; endswith;
    http.connection;
    content:"Keep-Alive"; depth:10; endswith;
    http.start;
    content:"dex.php|20|HTTP/1.1|0d 0a|Co"; fast_pattern;
    http.header_names;
    content:!"Content-Type|0d 0a|";
    content:!"User-Agent|0d 0a|";
    content:!"Accept-";
    content:!"Referer|0d 0a|";
    reference:url,github.com/nccgroup/Cyber-Defence/blob/master/Technical%20Notes/Red%20Leaves/Red%20Leaves%20technical%20note%20v1.0.pdf;
    reference:url,blog.jpcert.or.jp/2017/04/redleaves---malware-based-on-open-source-rat.html;
    classtype:targeted-activity;
    sid:2024175; rev:6;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_04_04, deployment Perimeter, malware_family RedLeaves, malware_family Red_Leaves, confidence High, signature_severity Major, tag APT, tag APT10, tag RedLeaves, tag c2, updated_at 2020_11_05, mitre_tactic_id TA0010, mitre_tactic_name Exfiltration, mitre_technique_id T1041, mitre_technique_name Exfiltration_Over_C2_Channel;
)