alert dns any any -> $HOME_NET any (msg:"ET DNS Reply Sinkhole - Zinkhole.org"; content:"|00 01 00 01|"; content:"|00 04 b0 1f 3e 4c|"; distance:4; within:6; classtype:trojan-activity; sid:2016419; rev:6; metadata:created_at 2013_02_16, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2022_07_13;)