Rule History

alert tls $HOME_NET any -> $EXTERNAL_NET any (msg:"ET INFO Observed Online PDF Viewer Domain (postoffice .adobe .com in TLS SNI)"; flow:established,to_server; tls.sni; bsize:20; content:"postoffice.adobe.com"; fast_pattern; classtype:misc-activity; sid:2064577; rev:1; metadata:attack_target Client_Endpoint, created_at 2025_09_11, deployment Perimeter, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_09_11;)