alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET RETIRED Yahoo IM Unavailable Status"; flow:established,to_server; content:"|59 47 00 0b 00 00 00 00 00 12 00 00 00 00|"; depth:55; classtype:policy-violation; sid:2001427; rev:7; metadata:created_at 2010_07_30, former_category CHAT, confidence Medium, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2026_08_28;)