alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET POLICY MP3 File Transfer Outbound"; flow:established; content:"ID3|03|"; content:"TIT2"; distance:6; within:10; reference:url,filext.com/detaillist.php?extdetail=mp3&Search=Search; classtype:policy-violation; sid:2002722; rev:4; metadata:created_at 2010_07_30, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)