alert dns $HOME_NET any -> any any (msg:"ET DNS Query to a *.top domain - Likely Hostile"; threshold:type limit, track by_src, count 1, seconds 30; dns.query; content:".top"; nocase; endswith; reference:url,www.symantec.com/connect/blogs/shady-tld-research-gdn-and-our-2016-wrap; reference:url,www.spamhaus.org/statistics/tlds/; classtype:bad-unknown; sid:2023883; rev:4; metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2017_02_07, deployment Perimeter, confidence Medium, signature_severity Major, updated_at 2020_09_15;)