ET HUNTING SUSPICIOUS SMTP Attachment Inbound PPT attachment with Embedded OLE Object M1

alert smtp $EXTERNAL_NET any -> $SMTP_SERVERS any (
    msg:"ET HUNTING SUSPICIOUS SMTP Attachment Inbound PPT attachment with Embedded OLE Object M1";
    flow:established,to_server;
    content:"|0D 0A 0D 0A|UEsDB";
    pcre:"/^[A-Za-z0-9\/\+\x0D\x0A]+?B[\x0d\x0a]{0,2}w[\x0d\x0a]{0,2}d[\x0d\x0a]{0,2}C[\x0d\x0a]{0,2}9[\x0d\x0a]{0,2}l[\x0d\x0a]{0,2}b[\x0d\x0a]{0,2}W[\x0d\x0a]{0,2}J[\x0d\x0a]{0,2}l[\x0d\x0a]{0,2}Z[\x0d\x0a]{0,2}G[\x0d\x0a]{0,2}R[\x0d\x0a]{0,2}p[\x0d\x0a]{0,2}b[\x0d\x0a]{0,2}m[\x0d\x0a]{0,2}d[\x0d\x0a]{0,2}z[\x0d\x0a]{0,2}L[\x0d\x0a]{0,2}2[\x0d\x0a]{0,2}9[\x0d\x0a]{0,2}s[\x0d\x0a]{0,2}Z[\x0d\x0a]{0,2}U[\x0d\x0a]{0,2}9[\x0d\x0a]{0,2}i[\x0d\x0a]{0,2}a[\x0d\x0a]{0,2}m[\x0d\x0a]{0,2}V[\x0d\x0a]{0,2}j[\x0d\x0a]{0,2}d/R";
    classtype:misc-activity;
    sid:2019406; rev:3;
    metadata:created_at 2014_10_15, confidence Medium, signature_severity Minor, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;
)