alert tcp $EXTERNAL_NET any -> $HOME_NET 25 (msg:"ET MALWARE Likely eCard Malware Laden Email Inbound"; flow:established,to_server; content:"|0d 0a|Subject|3a| You have received an eCard"; nocase; content:"e-card.zip"; nocase; reference:url,www.sophos.com/blogs/gc/g/2008/10/15/you-have-not-received-an-ecard/; classtype:trojan-activity; sid:2008674; rev:3; metadata:created_at 2010_07_30, confidence Medium, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)