ET MALWARE FRat WebSockets Request M2

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE FRat WebSockets Request M2";
    flow:established,to_server;
    http.start;
    content:"GET /socket.io/?__sails_io_sdk_version=1.2.1&__sails_io_sdk_platform=node&__sails_io_sdk_language=javascript&EIO=3&transport=websocket HTTP/1.1|0d 0a|Sec-WebSocket-Version|3a 20|13|0d 0a|Sec-WebSocket-Key|3a 20|"; startswith; fast_pattern;
    http.header;
    content:"Sec-WebSocket-Extensions|3a 20|permessage-deflate|3b 20|client_max_window_bits|0d 0a|";
    http.header_names;
    content:"|0d 0a|Sec-WebSocket-Version|0d 0a|Sec-WebSocket-Key|0d 0a|Connection|0d 0a|Upgrade|0d 0a|"; startswith;
    content:"Sec-WebSocket-Extensions|0d 0a|Host|0d 0a 0d 0a|"; endswith;
    classtype:command-and-control;
    sid:2030346; rev:1;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2020_06_16, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_06_16;
)