ET MALWARE [ANY.RUN] DarkGate Check-In HTTP Header (POST)

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE [ANY.RUN] DarkGate Check-In HTTP Header (POST)";
    flow:established,to_server;
    urilen:1;
    flowbits:set,ET.DarkGate.1;
    http.method;
    content:"POST";
    http.connection;
    content:"keep-alive"; bsize:10;
    http.content_type;
    content:"Application/octet-stream"; bsize:24;
    http.header;
    content:"Keep-Alive|3a 20|300|0d 0a|";
    content:"Content-Length|3a 20|";
    byte_test:0,>,40,0,relative,string,dec;
    byte_test:0,<,750,0,relative,string,dec;
    http.header_names;
    content:"|0d 0a|Host|0d 0a|Keep-Alive|0d 0a|Connection|0d 0a|User-Agent|0d 0a|Content-Type|0d 0a|Content-Length|0d 0a 0d 0a|"; bsize:76;
    http.user_agent;
    content:"Mozilla|2f|4|2e|0|20 28|compatible|3b 20|Synapse|29|"; bsize:33; fast_pattern;
    threshold:type limit,seconds 300,count 1,track by_src;
    reference:md5,4d26c05426247f7a4f784967c7b0faa2;
    reference:url,app.any.run/tasks/fb92bcf3-3413-4bca-807a-fb002ac48b18;
    reference:url,malware-traffic-analysis.net/2023/10/12/index.html;
    reference:url,community.emergingthreats.net/t/darkgate/1033;
    classtype:command-and-control;
    sid:2048558; rev:1;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2023_10_13, deployment Perimeter, malware_family DarkGate, confidence High, signature_severity Critical, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_12_28, reviewed_at 2023_10_13;
    target:src_ip;
)