Rule History

alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET INFO Observed DNS Over HTTPS Domain (xray .krnl .eu in TLS SNI)"; flow:established,to_server; tls.sni; bsize:12; content:"xray.krnl.eu"; fast_pattern; reference:url,github.com/curl/curl/wiki/DNS-over-HTTPS; classtype:misc-activity; sid:2048604; rev:4; metadata:created_at 2023_10_18, deployment Perimeter, performance_impact Low, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2024_12_01, reviewed_at 2024_03_18, mitre_tactic_id TA0011, mitre_tactic_name Command_And_Control, mitre_technique_id T1572, mitre_technique_name Protocol_Tunneling;)