alert dns $HOME_NET any -> $EXTERNAL_NET any (msg:"ET HUNTING Observed Query to .fyi TLD"; dns.query; content:".fyi"; nocase; endswith; fast_pattern; reference:url,www.spamhaus.org/statistics/tlds/; classtype:bad-unknown; sid:2044178; rev:1; metadata:attack_target Client_Endpoint, created_at 2023_02_13, deployment Perimeter, performance_impact Significant, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_02_13;)