ET MALWARE Remote Utility Access Tool Key SMTP Exfil

alert smtp $HOME_NET any -> $EXTERNAL_NET 587 (
    msg:"ET MALWARE Remote Utility Access Tool Key SMTP Exfil";
    flow:established,to_server;
    content:"|40|pcomail|2e|com|3e 0d 0a|Subject|3a 0d 0a 20 3d 3f|UTF|2d|8|3f|B|3f|7"; fast_pattern;
    content:"To|3a 20|"; distance:0;
    content:"@pcomail.com"; distance:0;
    content:"UmVtb3RlIFV0aWxpdGllc+"; distance:0;
    reference:md5,305d37bb6e5c51191508761cee43f0e0;
    classtype:trojan-activity;
    sid:2043237; rev:1;
    metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2023_01_06, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_01_06;
)