alert tcp $EXTERNAL_NET 1863 -> $HOME_NET any (msg:"GPL CHAT MSN outbound file transfer accept"; flow:established; content:"MSG "; depth:4; content:"Content-Type|3A| application/x-msnmsgrp2p"; distance:0; nocase; content:"MSNSLP/1.0 200 OK"; distance:0; nocase; classtype:policy-violation; sid:2101988; rev:6; metadata:created_at 2010_09_23, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)