:tocdepth: 3 base/protocols/smtp/main.zeek ============================= .. zeek:namespace:: SMTP :Namespace: SMTP :Imports: :doc:`base/frameworks/notice/weird.zeek `, :doc:`base/protocols/conn/removal-hooks.zeek `, :doc:`base/utils/addrs.zeek `, :doc:`base/utils/directions-and-hosts.zeek `, :doc:`base/utils/email.zeek ` Summary ~~~~~~~ Runtime Options ############### ====================================================================================== ================================================================ :zeek:id:`SMTP::mail_path_capture`: :zeek:type:`Host` :zeek:attr:`&redef` Direction to capture the full "Received from" path. :zeek:id:`SMTP::mail_transaction_validation`: :zeek:type:`bool` :zeek:attr:`&redef` When seeing a RCPT TO or DATA command, validate that it has been preceded by a MAIL FROM or RCPT TO command, respectively, else log a weird and possibly disable the SMTP analyzer upon too many invalid transactions. :zeek:id:`SMTP::max_invalid_mail_transactions`: :zeek:type:`count` :zeek:attr:`&redef` Disable the SMTP analyzer when that many invalid transactions have been observed in an SMTP session. ====================================================================================== ================================================================ Types ##### ============================================= = :zeek:type:`SMTP::Info`: :zeek:type:`record` :zeek:type:`SMTP::State`: :zeek:type:`record` ============================================= = Redefinitions ############# ==================================================================== ============================================================= :zeek:type:`Log::ID`: :zeek:type:`enum` * :zeek:enum:`SMTP::LOG` :zeek:type:`connection`: :zeek:type:`record` :New Fields: :zeek:type:`connection` smtp: :zeek:type:`SMTP::Info` :zeek:attr:`&optional` smtp_state: :zeek:type:`SMTP::State` :zeek:attr:`&optional` :zeek:id:`likely_server_ports`: :zeek:type:`set` :zeek:attr:`&redef` ==================================================================== ============================================================= Events ###### ============================================= = :zeek:id:`SMTP::log_smtp`: :zeek:type:`event` ============================================= = Hooks ##### ============================================================== ======================= :zeek:id:`SMTP::finalize_smtp`: :zeek:type:`Conn::RemovalHook` SMTP finalization hook. :zeek:id:`SMTP::log_policy`: :zeek:type:`Log::PolicyHook` ============================================================== ======================= Functions ######### ================================================ =========================================================== :zeek:id:`SMTP::describe`: :zeek:type:`function` Create an extremely shortened representation of a log line. ================================================ =========================================================== Detailed Interface ~~~~~~~~~~~~~~~~~~ Runtime Options ############### .. zeek:id:: SMTP::mail_path_capture :source-code: base/protocols/smtp/main.zeek 91 91 :Type: :zeek:type:`Host` :Attributes: :zeek:attr:`&redef` :Default: ``ALL_HOSTS`` Direction to capture the full "Received from" path. REMOTE_HOSTS - only capture the path until an internal host is found. LOCAL_HOSTS - only capture the path until the external host is discovered. ALL_HOSTS - always capture the entire path. NO_HOSTS - never capture the path. .. zeek:id:: SMTP::mail_transaction_validation :source-code: base/protocols/smtp/main.zeek 105 105 :Type: :zeek:type:`bool` :Attributes: :zeek:attr:`&redef` :Default: ``T`` When seeing a RCPT TO or DATA command, validate that it has been preceded by a MAIL FROM or RCPT TO command, respectively, else log a weird and possibly disable the SMTP analyzer upon too many invalid transactions. .. zeek:id:: SMTP::max_invalid_mail_transactions :source-code: base/protocols/smtp/main.zeek 109 109 :Type: :zeek:type:`count` :Attributes: :zeek:attr:`&redef` :Default: ``25`` Disable the SMTP analyzer when that many invalid transactions have been observed in an SMTP session. Types ##### .. zeek:type:: SMTP::Info :source-code: base/protocols/smtp/main.zeek 14 69 :Type: :zeek:type:`record` ts: :zeek:type:`time` :zeek:attr:`&log` Time when the message was first seen. uid: :zeek:type:`string` :zeek:attr:`&log` Unique ID for the connection. id: :zeek:type:`conn_id` :zeek:attr:`&log` The connection's 4-tuple of endpoint addresses/ports. trans_depth: :zeek:type:`count` :zeek:attr:`&log` A count to represent the depth of this message transaction in a single connection where multiple messages were transferred. helo: :zeek:type:`string` :zeek:attr:`&log` :zeek:attr:`&optional` Contents of the Helo header. mailfrom: :zeek:type:`string` :zeek:attr:`&log` :zeek:attr:`&optional` Email addresses found in the From header. rcptto: :zeek:type:`set` [:zeek:type:`string`] :zeek:attr:`&log` :zeek:attr:`&optional` Email addresses found in the Rcpt header. date: :zeek:type:`string` :zeek:attr:`&log` :zeek:attr:`&optional` Contents of the Date header. from: :zeek:type:`string` :zeek:attr:`&log` :zeek:attr:`&optional` Contents of the From header. to: :zeek:type:`set` [:zeek:type:`string`] :zeek:attr:`&log` :zeek:attr:`&optional` Contents of the To header. cc: :zeek:type:`set` [:zeek:type:`string`] :zeek:attr:`&log` :zeek:attr:`&optional` Contents of the CC header. reply_to: :zeek:type:`string` :zeek:attr:`&log` :zeek:attr:`&optional` Contents of the ReplyTo header. msg_id: :zeek:type:`string` :zeek:attr:`&log` :zeek:attr:`&optional` Contents of the MsgID header. in_reply_to: :zeek:type:`string` :zeek:attr:`&log` :zeek:attr:`&optional` Contents of the In-Reply-To header. subject: :zeek:type:`string` :zeek:attr:`&log` :zeek:attr:`&optional` Contents of the Subject header. x_originating_ip: :zeek:type:`addr` :zeek:attr:`&log` :zeek:attr:`&optional` Contents of the X-Originating-IP header. first_received: :zeek:type:`string` :zeek:attr:`&log` :zeek:attr:`&optional` Contents of the first Received header. second_received: :zeek:type:`string` :zeek:attr:`&log` :zeek:attr:`&optional` Contents of the second Received header. last_reply: :zeek:type:`string` :zeek:attr:`&log` :zeek:attr:`&optional` The last message that the server sent to the client. path: :zeek:type:`vector` of :zeek:type:`addr` :zeek:attr:`&log` :zeek:attr:`&optional` The message transmission path, as extracted from the headers. user_agent: :zeek:type:`string` :zeek:attr:`&log` :zeek:attr:`&optional` Value of the User-Agent header from the client. tls: :zeek:type:`bool` :zeek:attr:`&log` :zeek:attr:`&default` = ``F`` :zeek:attr:`&optional` Indicates that the connection has switched to using TLS. process_received_from: :zeek:type:`bool` :zeek:attr:`&default` = ``T`` :zeek:attr:`&optional` Indicates if the "Received: from" headers should still be processed. has_client_activity: :zeek:type:`bool` :zeek:attr:`&default` = ``F`` :zeek:attr:`&optional` Indicates if client activity has been seen, but not yet logged. process_smtp_headers: :zeek:type:`bool` :zeek:attr:`&default` = ``T`` :zeek:attr:`&optional` Indicates if the SMTP headers should still be processed. entity_count: :zeek:type:`count` :zeek:attr:`&default` = ``0`` :zeek:attr:`&optional` entity: :zeek:type:`SMTP::Entity` :zeek:attr:`&optional` (present if :doc:`/scripts/base/protocols/smtp/entities.zeek` is loaded) The current entity being seen. fuids: :zeek:type:`vector` of :zeek:type:`string` :zeek:attr:`&log` :zeek:attr:`&default` = ``[]`` :zeek:attr:`&optional` (present if :doc:`/scripts/base/protocols/smtp/files.zeek` is loaded) An ordered vector of file unique IDs seen attached to the message. is_webmail: :zeek:type:`bool` :zeek:attr:`&log` :zeek:attr:`&default` = ``F`` :zeek:attr:`&optional` (present if :doc:`/scripts/policy/protocols/smtp/software.zeek` is loaded) Boolean indicator of if the message was sent through a webmail interface. .. zeek:type:: SMTP::State :source-code: base/protocols/smtp/main.zeek 71 84 :Type: :zeek:type:`record` helo: :zeek:type:`string` :zeek:attr:`&optional` messages_transferred: :zeek:type:`count` :zeek:attr:`&default` = ``0`` :zeek:attr:`&optional` Count the number of individual messages transmitted during this SMTP session. Note, this is not the number of recipients, but the number of message bodies transferred. pending_messages: :zeek:type:`set` [:zeek:type:`SMTP::Info`] :zeek:attr:`&optional` trans_mail_from_seen: :zeek:type:`bool` :zeek:attr:`&default` = ``F`` :zeek:attr:`&optional` trans_rcpt_to_seen: :zeek:type:`bool` :zeek:attr:`&default` = ``F`` :zeek:attr:`&optional` invalid_transactions: :zeek:type:`count` :zeek:attr:`&default` = ``0`` :zeek:attr:`&optional` analyzer_id: :zeek:type:`count` :zeek:attr:`&optional` mime_depth: :zeek:type:`count` :zeek:attr:`&default` = ``0`` :zeek:attr:`&optional` (present if :doc:`/scripts/base/protocols/smtp/entities.zeek` is loaded) Track the number of MIME encoded files transferred during a session. Events ###### .. zeek:id:: SMTP::log_smtp :source-code: base/protocols/smtp/main.zeek 96 96 :Type: :zeek:type:`event` (rec: :zeek:type:`SMTP::Info`) Hooks ##### .. zeek:id:: SMTP::finalize_smtp :source-code: base/protocols/smtp/main.zeek 398 402 :Type: :zeek:type:`Conn::RemovalHook` SMTP finalization hook. Remaining SMTP info may get logged when it's called. .. zeek:id:: SMTP::log_policy :source-code: base/protocols/smtp/main.zeek 12 12 :Type: :zeek:type:`Log::PolicyHook` Functions ######### .. zeek:id:: SMTP::describe :source-code: base/protocols/smtp/main.zeek 413 438 :Type: :zeek:type:`function` (rec: :zeek:type:`SMTP::Info`) : :zeek:type:`string` Create an extremely shortened representation of a log line.