alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET POLICY Google IM traffic friend invited"; flow:to_server; content:"><invitati"; content:"on xmlns=\"google"; reference:url,www.google.com/talk; classtype:policy-violation; sid:2002333; rev:6; metadata:created_at 2010_07_30, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)