alert dns $HOME_NET any -> any any (msg:"ET POLICY DNS Query to .onion proxy Domain (door2tor.org)"; dns.query; content:".door2tor.org"; nocase; endswith; fast_pattern; reference:url,en.wikipedia.org/wiki/Tor_(anonymity_network); classtype:bad-unknown; sid:2020111; rev:6; metadata:affected_product Any, attack_target Client_Endpoint, created_at 2015_01_07, deployment Perimeter, confidence Medium, signature_severity Informational, tag DNS_Onion_Query, updated_at 2020_09_17;)