alert tcp [$HOME_NET,$HTTP_SERVERS] any -> $EXTERNAL_NET any (msg:"ET POLICY LDAPSv3 LDAPS_START_TLS Request Outbound"; flow:established,to_server; flowbits:set,ET.LDAPSBindRequest; flowbits:isnotset,ET.LDAPSBindRequest; stream_size:server,<,5; content:"|30 1d 02 01|"; startswith; content:"|77 18 80 16 31 2e 33 2e 36 2e 31 2e 34 2e 31 2e 31 34 36 36 2e 32 30 30 33 37|"; endswith; fast_pattern; reference:url,ldap.com/ldapv3-wire-protocol-reference-extended/; classtype:bad-unknown; sid:2034719; rev:2; metadata:attack_target Client_and_Server, created_at 2021_12_14, deployment Perimeter, confidence High, signature_severity Informational, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_12_15;)