alert udp $EXTERNAL_NET any -> $HOME_NET 53 (msg:"ET POLICY DNS Update From External net"; byte_test:1,!&,128,2; byte_test:1,!&,64,2; byte_test:1,&,32,2; byte_test:1,!&,16,2; byte_test:1,&,8,2; classtype:policy-violation; sid:2009702; rev:6; metadata:created_at 2010_07_30, confidence High, signature_severity Informational, updated_at 2023_02_16;)