alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"ET INFO HTTP Request to a *.top domain"; flow:established,to_server; threshold:type limit, track by_src, count 1, seconds 30; http.host; content:".top"; fast_pattern; pcre:"/^(\x3a\d{1,5})?$/R"; 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:2023882; rev:5; 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 High, signature_severity Informational, updated_at 2022_11_21;)