alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET INFO Observed URL Shortening Domain (da .gd in TLS SNI)"; flow:established,to_server; tls.sni; content:"da.gd"; bsize:5; fast_pattern; classtype:bad-unknown; sid:2045306; rev:1; metadata:attack_target Client_Endpoint, created_at 2023_05_03, deployment Perimeter, performance_impact Low, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2023_05_03, reviewed_at 2023_12_01;)