alert tcp $EXTERNAL_NET any -> $SMTP_SERVERS 25 (msg:"ET DELETED WU Malicious Spam Inbound"; flow:established,to_server; content:"Content-Disposition|3A| attachment|3b|"; nocase; content:"filename"; within:100; content:"WU_Details_"; within:50; pcre:"/filename\s*=\s*"WU_Details_.....\.zip/m"; classtype:trojan-activity; sid:2010376; rev:3; metadata:created_at 2010_07_30, signature_severity Unknown, updated_at 2019_07_26;)