alert http $HOME_NET any <> $EXTERNAL_NET any (msg:"ET CHAT General MSN Chat Activity"; flow:established; http.header; content:"Content-Type|3A|"; content:"application/x-msn-messenger"; reference:url,www.hypothetic.org/docs/msn/general/http_examples.php; classtype:policy-violation; sid:2009375; rev:9; metadata:created_at 2010_07_30, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2020_12_03;)