alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"ET CHAT Yahoo IM conference request"; flow:to_server,established; content:"<R"; depth:2; pcre:"/^\x3c(REQIMG|RVWCFG)\x3e/ism"; classtype:policy-violation; sid:2001263; rev:5; metadata:created_at 2010_07_30, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)