ET MALWARE Possible SQUIRRELWAFFLE Server Response

alert http $EXTERNAL_NET any -> $HOME_NET any (
    msg:"ET MALWARE Possible SQUIRRELWAFFLE Server Response";
    flow:established,to_client;
    http.stat_code;
    content:"200";
    http.content_type;
    content:"text/html|3b 20|charset=UTF-8"; bsize:24;
    file.data;
    content:"|0d 0d 0d 09 09 09 0a 0a 0a|"; startswith; fast_pattern;
    content:"|0a 0a 0a 09 09 09 0d 0d 0d|"; endswith;
    classtype:command-and-control;
    sid:2033984; rev:2;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_09_17, deployment Perimeter, malware_family SQUIRRELWAFFLE, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_09_22;
)