ET MALWARE MSIL/BlackGuard Stealer Variant Exfil via Telegram

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"ET MALWARE MSIL/BlackGuard Stealer Variant Exfil via Telegram";
    flow:established,to_server;
    http.method;
    content:"POST";
    http.uri;
    content:"/bot"; depth:4;
    content:"/sendDocument?chat_id="; distance:0;
    content:"&caption="; distance:0;
    content:"|e2 9a 99 ef b8 8f 20|Windows|20|"; distance:0; fast_pattern;
    content:"BROWSER|3a 0a|"; distance:0;
    content:"|0a 0a 20|Link|20|"; distance:0;
    http.host;
    content:"api.telegram.org";
    http.request_body;
    content:"Content-Disposition|3a 20|form-data|3b 20|name|3d 22|document|22 3b 20|filename|3d 22|";
    content:".zip|22 0d 0a|Content-Type|3a 20|application/x-ms-dos-executable"; distance:0;
    reference:md5,d4e02002916f18576204a3f1722a958b;
    reference:md5,eb6c563af372d1af92ac2b60438d076d;
    reference:md5,ae84bf01058b29c178ae724df445c0c8;
    reference:url,twitter.com/3xp0rtblog/status/1499748871362261001;
    classtype:command-and-control;
    sid:2035397; rev:3;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2022_03_07, deployment Perimeter, deployment SSLDecrypt, malware_family BlackGuard, performance_impact Low, confidence Medium, signature_severity Major, tag Stealer, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_03_08;
)