ET MALWARE TA450/MuddyWater CnC Victim Checkin

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE TA450/MuddyWater CnC Victim Checkin";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.uri; bsize:5;
    content:"/ercv"; fast_pattern;
    http.user_agent; bsize:11;
    content:"application";
    threshold:type limit,count 1,seconds 300,track by_src;
    reference:url,group-ib.com/blog/muddywater-operation-olalampo;
    classtype:command-and-control;
    sid:2067861; rev:1;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, tls_state TLSDecrypt, created_at 2026_02_20, deployment Perimeter, deployment SSLDecrypt, confidence High, signature_severity Critical, tag MuddyWater, tag c2, tag TA450, updated_at 2026_02_20, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1071, mitre_technique_name Application_Layer_Protocol;
    target:src_ip;
)