ET MALWARE Win32/AnteFrigus Ransomware Activity

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE Win32/AnteFrigus Ransomware Activity";
    flow:established,to_server;
    http.method;
    content:"GET";
    http.uri;
    content:!".";
    content:!"&";
    content:!"?";
    http.user_agent;
    content:"|20|Gb</br>"; endswith;
    http.header;
    content:"|20|Gb</br>|0d 0a|Host|3a 20|"; fast_pattern;
    http.header_names;
    content:!"Accept";
    content:!"Cache";
    content:!"Referer";
    reference:md5,b34f1592bce63de77b87d1e61bce66e5;
    classtype:command-and-control;
    sid:2028966; rev:1;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2019_11_13, deployment Perimeter, malware_family Win32_AnteFrigus, confidence High, signature_severity Major, tag Ransomware, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_11_13, mitre_tactic_id TA0040, mitre_tactic_name Impact, mitre_technique_id T1486, mitre_technique_name Data_Encrypted_for_Impact;
)