alert tcp $EXTERNAL_NET any -> $HOME_NET any (msg:"ET EXPLOIT VNC Authentication Reply"; flowbits:isset,BSvnc.auth.offered; flow:established; dsize:16; flowbits:unset,BSvnc.auth.offered; flowbits:noalert; flowbits:set,BSvnc.auth.agreed; reference:url,www.realvnc.com/docs/rfbproto.pdf; classtype:attempted-admin; sid:2002915; rev:6; metadata:created_at 2010_07_30, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2019_07_26;)