alert dns any any -> $HOME_NET any (msg:"ET DELETED Team Cymru Sinkhole DNS Reply"; content:"|00 01 00 01|"; content:"|00 04 26 E5 46 04|"; distance:4; within:6; classtype:trojan-activity; sid:2021020; rev:2; metadata:created_at 2015_04_28, signature_severity Unknown, updated_at 2022_07_13;)