ET HUNTING SUSPICIOUS SMTP Attachment Inbound PPT attachment with Embedded OLE Object M3

alert smtp $EXTERNAL_NET any -> $SMTP_SERVERS any (
    msg:"ET HUNTING SUSPICIOUS SMTP Attachment Inbound PPT attachment with Embedded OLE Object M3";
    flow:established,to_server;
    content:"|0D 0A 0D 0A|UEsDB";
    pcre:"/^[A-Za-z0-9\/\+\x0D\x0A]+?c[\x0d\x0a]{0,2}H[\x0d\x0a]{0,2}Q[\x0d\x0a]{0,2}v[\x0d\x0a]{0,2}Z[\x0d\x0a]{0,2}W[\x0d\x0a]{0,2}1[\x0d\x0a]{0,2}i[\x0d\x0a]{0,2}Z[\x0d\x0a]{0,2}W[\x0d\x0a]{0,2}R[\x0d\x0a]{0,2}k[\x0d\x0a]{0,2}a[\x0d\x0a]{0,2}W[\x0d\x0a]{0,2}5[\x0d\x0a]{0,2}n[\x0d\x0a]{0,2}c[\x0d\x0a]{0,2}y[\x0d\x0a]{0,2}9[\x0d\x0a]{0,2}v[\x0d\x0a]{0,2}b[\x0d\x0a]{0,2}G[\x0d\x0a]{0,2}V[\x0d\x0a]{0,2}P[\x0d\x0a]{0,2}Y[\x0d\x0a]{0,2}m[\x0d\x0a]{0,2}p[\x0d\x0a]{0,2}l[\x0d\x0a]{0,2}Y[\x0d\x0a]{0,2}3/R";
    classtype:misc-activity;
    sid:2019408; rev:2;
    metadata:created_at 2014_10_15, confidence Medium, signature_severity Minor, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;
)