300-720 Securing Email with Cisco Email Security Appliance (300-720 SESA) Questions and Answers

To combat backscatter, which is a type of spam that consists of bounce messages sent to forged sender addresses, the administrator must enable the Bounce Verification feature under Security Settings. This feature allows the appliance to verify whether a bounce message is legitimate or not by checking if the original message was sent from the appliance. If not, the bounce message is considered as backscatter and can be dropped or quarantined. References: [Cisco Secure Email Gateway Administrator Guide - Configuring Bounce Verification]

spf-status is the section of the filter that must be modified to correct this behavior. spf-status is a condition that determines whether a message matches the content filter rule based on the result of SPF verification, such as pass, fail, neutral, etc.

The content filter in the exhibit has a spf-status condition set to “Pass”, which means that it will match messages that passed SPF verification and apply the action of “Quarantine”. This is the opposite of what the network engineer intended to do.

To correct this behavior, the network engineer can modify the spf-status condition to “Fail”, which means that it will match messages that failed SPF verification and apply the action of “Quarantine”.

The other options are not valid sections of the filter that must be modified to correct this behavior, because they do not affect the spf-status condition.

References: [User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway], page 8-3 and page 8-4.

The default port to deliver emails from the Cisco ESA to the Cisco SMA using the centralized Spam Quarantine is 6025. This is the default value for the Port setting in the External Spam Quarantine configuration on Cisco ESA. This port must be open on both Cisco ESA and Cisco SMA for the communication to work.

References: User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway, page 10-4.

To protect against Directory Harvest Attacks, the administrator must configure Directory Harvest Attack Prevention in the mail flow policy that applies to the listener. This will enable the Cisco Secure Email Gateway to reject or throttle messages that are sent to invalid recipients by checking the LDAP server for valid email addresses. References: [Cisco Secure Email Gateway Administrator Guide - Configuring Directory Harvest Attack Prevention]

A filter is a method that enables an engineer to deliver a flagged message to a specific virtual gateway address in the most flexible way. A filter is a rule that allows Cisco ESA to perform actions on messages based on predefined or custom conditions, such as headers, envelope, body, attachments, etc.

To deliver a flagged message to a specific virtual gateway address using a filter, the engineer can create a content filter or message filter that matches the flag condition and applies an action of “deliver via alternate host” with the virtual gateway address as the parameter.

The other options are not methods that enable an engineer to deliver a flagged message to a specific virtual gateway address in the most flexible way, because they have more limitations or requirements than using a filter.

References: User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway, page 8-3 and page 8-7.

Modify Subject is an additional option that should be used to help the end users be aware of the elevated risk of interacting with these messages. Modify Subject allows the administrator to add a prefix or suffix to the message subject, such as “[SPF Fail]”, to indicate that the message has failed the SPF verification and may be fraudulent or spoofed.

The other options are not valid additional options to help the end users be aware of the elevated risk of interacting with these messages, because they do not affect the message subject or provide any warning to the end users.

References: User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway, page 8-7 and page 8-8.

Message-filter order and MIME structure of the message are two factors that must be considered when message filter processing is configured on Cisco ESA. Message-filter order determines the sequence in which message filters are evaluated and applied to incoming messages, which can affect the final outcome of the filtering process. MIME structure of the message determines how message filters match against different parts of the message, such as headers, body, attachments, etc., which can affect the accuracy and performance of the filtering process.

References: User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway, page 3-3 and page 3-5.

Outbreak Filters can take the action of rewriting URLs to redirect traffic to potentially harmful websites through a web security proxy. This allows the Cisco Secure Email Gateway to scan the content of the websites and block or warn the user if they are malicious or undesirable. This action can stop small-scale and nonviral attacks, such as phishing scams and malware distribution sites, that may not be detected by other filters. References: [Cisco Secure Email Gateway Administrator Guide - Configuring Outbreak Filters]

Configuring DomainKeys and DKIM Signing:

-Signing Keys

-Public Keys

-Domain Profiles

Creating Domain Profiles:

Step 1

-Choose Mail Policies > Signing Profiles.

Step 2

-In the Domain Signing Profiles section, click Add Profile.

https://www.cisco.com/c/en/us/td/docs/security/esa/esa14-0/user_guide/b_ESA_Admin_Guide_14-0/b_ESA_Admin_Guide_12_1_chapter_010110.html?bookSearch=true

The Outbreak Filters feature uses three tactics to protect your users from outbreaks:

Delay.

Redirect.

Modify.

https://www.cisco.com/c/en/us/td/docs/security/esa/esa12-0/user_guide/b_ESA_Admin_Guide_12_0/b_ESA_Admin_Guide_chapter_01110.html

Non-final actions are actions that do not terminate the message filter evaluation, such as adding headers, setting variables, logging, etc. Final actions are actions that end the message filter evaluation and determine the fate of the message, such as accept, drop, bounce, quarantine, etc.

References: User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway, page 3-4.

The altsrchost command enables an engineer to deliver a flagged message to a specific virtual gateway address in the most flexible way. This command allows you to specify an alternate source host for messages that match a message filter. You can use this command to route messages to different virtual gateways based on the message content or attributes.

References: Securing Email with Cisco Email Security Appliance (SESA) v3.1, Module 5: Using Message Filters to Enforce Email Policies, Lesson 1: Using Message Filters

Table Description automatically generated

• Public/Private keypair. A public/private keypair is a pair of cryptographic keys that are used to generate and verify digital signatures. The private key is used to sign the email message, while the public key is used to verify the signature. The public key is published in a DNS record, while the private key is stored on the Cisco Secure Email Gateway appliance[1, p. 2].
• Domain signing profile. A domain signing profile is a configuration that specifies the domain and selector to use for signing outgoing messages, as well as the signing algorithm, canonicalization method, and header fields to include in the signature. You can create multiple domain signing profiles for different domains or subdomains[1, p. 3].

The other options are not valid because:

• A. DMARC verification profile is not a component for utilizing a digital signature in outgoing emails. It is a component for verifying the authenticity of incoming emails based on SPF and DKIM results[2, p. 1].
• B. SPF record is not a component for utilizing a digital signature in outgoing emails. It is a component for validating the sender IP address of incoming emails based on a list of authorized IP addresses published in a DNS record[3, p. 1].
• E. PKI certificate is not a component for utilizing a digital signature in outgoing emails. It is a component for encrypting and decrypting email messages based on a certificate authority that issues and validates certificates[4, p. 1].

Geolocation-based filtering and senderbase reputation filtering are two features of Cisco Email Security that can be added to a Sender Group to protect an organization against email threats. Geolocation-based filtering allows Cisco ESA to accept or reject connections from email servers based on their geographic location, such as country or continent. Senderbase reputation filtering allows Cisco ESA to reject or throttle connections from email servers based on their reputation score, which is calculated by Talos using sensor information from various sources.

References: User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway, page 5-4 and page 6-2.

Spam threshold is a setting that determines the minimum score that a message must have to be classified as spam by Cisco ESA. The lower the threshold, the more aggressive the spam detection is.

References: User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway, page 6-5.

To allow the Cisco ESA to encrypt an email using the CRES (Cisco Registered Envelope Service), a provisioned email encryption profile must be configured on Cisco ESA. A provisioned email encryption profile is a type of encryption profile that specifies how messages are encrypted using CRES, such as the encryption key strength, the notification options, the branding settings, etc.

References: User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway, page 12-4.

To enable File Reputation and File Analysis on the Cisco Secure Email Gateway appliance, the administrator must configure the appliance to use SSL for the connection to the File Reputation server. This will ensure that the communication between the appliance and the cloud service is secure and encrypted. The administrator must also upload a valid certificate from a trusted CA on the appliance for this purpose. The other options are not required or effective for this task. References: [Cisco Secure Email Gateway Administrator Guide - Configuring File Reputation and File Analysis]

Load balancing and failover are two configurations that can be used on multiple LDAP servers to connect with Cisco ESA. Load balancing means that Cisco ESA will distribute the LDAP queries among the available LDAP servers in a round-robin fashion, improving the performance and efficiency of the LDAP queries. Failover means that Cisco ESA will switch to another LDAP server if the current one is unavailable or unresponsive, ensuring the continuity and reliability of the LDAP queries.

References: User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway, page 10-8.

You can enter multiple host names to configure the LDAP servers for failover or load-balancing. Separate multiple entries with commas.

To enable LDAP recipient verification on a Cisco Secure Email Gateway appliance, you need to configure the LDAP query on a listener and configure LDAP server profiles. The LDAP query specifies the criteria for matching recipient addresses against an LDAP directory. The LDAP server profile defines the connection settings and authentication credentials for accessing an LDAP server2. References = User Guide for AsyncOS 12.0 for Cisco Email Security Appliances - GD (General Deployment) - Configuring LDAP Queries [Cisco Secure Email Gateway] - Cisco

SenderBase Reputation Filtering is a feature that allows Cisco ESA to reject or throttle connections from email servers based on their reputation score, which is calculated by Talos using sensor information from various sources.

References: User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway, page 6-2.

To encrypt SMTP with TLS on a Cisco Secure Email Gateway appliance when the sender requires TLS verification, the components that are required are an X.509 certificate and matching private key from a CA. The certificate must be signed by a trusted CA and contain the domain name or IP address of the listener in the Subject or Subject Alternative Name fields. The private key must be unencrypted and match the certificate. References: [Cisco Secure Email Gateway Administrator Guide - Configuring TLS]

 in the spam quarantine section, you can configure settings for access to the spam quarantine, and by default, HTTP uses port 82 and HTTPS uses port 83.

The correct order of commands to set filter 2 to active on the CLI of Cisco ESA is:

• filters, which enters the message filter mode.
• set, which sets the status of one or more message filters.
• 2, which specifies the message filter number.
• 1, which sets the status of message filter 2 to active.

The other options are not valid orders of commands to set filter 2 to active on the CLI of Cisco ESA, because they use incorrect commands or parameters.

References: User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway, page A-6 and page A-7.

DLP (Data Loss Prevention) is a security service that is configured only through an outgoing mail policy on Cisco ESA. DLP allows Cisco ESA to scan outgoing messages for sensitive or confidential data, such as credit card numbers, social security numbers, health records, etc., and apply appropriate actions, such as encrypt, quarantine, notify, etc., to prevent data leakage or loss.

References: User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway, page 9-2.

Reference https://www.cisco.com/c/en/us/td/docs/security/esa/esa11-0/user_guide_fs/ b_ESA_Admin_Guide_11_0/b_ESA_Admin_Guide_chapter_01001.html

To meet the security policy of allowing visibility into what the URL is but not allowing the user to click it, the administrator must defang the URL. This means that the URL will be modified in a way that it is still readable by humans but not clickable by browsers. For example, http://example.com could be defanged as hxxp://example[.]com.  References: [Cisco Secure Email Gateway Administrator Guide - Defanging URLs in Messages]

To use the centralized spam quarantine on the Cisco Secure Email and Web Manager appliance, the administrator must disable the local spam quarantine on the Cisco Secure Email Gateway appliances. This will prevent messages from being stored in both quarantines and avoid confusion for end users and administrators. References: [Cisco Secure Email and Web Manager User Guide - Configuring Centralized Spam Quarantine]

Spam threshold is a setting that determines the minimum score that a message must have to be classified as spam by Cisco ESA. The lower the threshold, the more aggressive the spam detection is.

References: User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway, page 6-5.

When Cisco ESA is configured to perform antivirus scanning, the default timeout value is 60 seconds, which means that Cisco ESA will wait for 60 seconds for the antivirus engine to scan a message before applying the configured action for unscannable messages, such as deliver, drop, or quarantine.

References: User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway, page 7-3.

spf-status is the section of the filter that must be modified to correct this behavior. spf-status is a condition that determines whether a message matches the content filter rule based on the result of SPF verification, such as pass, fail, neutral, etc.

The content filter in the exhibit has a spf-status condition set to “Pass”, which means that it will match messages that passed SPF verification and apply the action of “Quarantine”. This is the opposite of what the network engineer intended to do.

To correct this behavior, the network engineer can modify the spf-status condition to “Fail”, which means that it will match messages that failed SPF verification and apply the action of “Quarantine”.

The other options are not valid sections of the filter that must be modified to correct this behavior, because they do not affect the spf-status condition.

References: [User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway], page 8-3 and page 8-4.

• Define an LDAP group query to specify users to whom the mail policy rules apply. This way, you can create a custom group of executive users and apply different mail policies to them based on their LDAP attributes[4, p. 2].
• Create content filters for actions to take on messages that contain specific data. Content filters allow you to scan the message body and attachments for keywords, phrases, or patterns that match your criteria and perform actions such as quarantine, encrypt, or drop the message[4, p. 7].

The other options are not valid because:

• C. Uploading a csv file containing the email addresses for the users for whom you want to create mail policies is not a supported feature of Cisco Secure Email1.
• D. Enabling the content-scanning features you want to use with mail policies is not necessary, as content scanning is enabled by default for all incoming and outgoing messages[4, p. 6].
• E. Defining the default mail policies for incoming or outgoing messages is not sufficient, as default mail policies apply to all users and do not allow for differentiation based on user groups[4, p. 2].

• System: This is the default list of trusted certificate authorities that is provided by Cisco and updated automatically. It contains the certificates of well-known and widely used certificate authorities, such as VeriSign, Thawte, and GoDaddy.
• Custom: This is the list of additional certificate authorities that you can add manually or import from a file. It allows you to trust certificates that are issued by your own or third-party certificate authorities that are not included in the system list.

Spam Quarantine End-User Authentication Query is a query that Cisco ESA performs against an LDAP server to validate the end-user credentials during login to the End-User Quarantine.

References: User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway, page 10-9.

Non-final actions are actions that do not terminate the message filter evaluation, such as adding headers, setting variables, logging, etc. Final actions are actions that end the message filter evaluation and determine the fate of the message, such as accept, drop, bounce, quarantine, etc.

References: User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway, page 3-4.

To allow the Cisco ESA to encrypt an email using the CRES (Cisco Registered Envelope Service), a provisioned email encryption profile must be configured on Cisco ESA. A provisioned email encryption profile is a type of encryption profile that specifies how messages are encrypted using CRES, such as the encryption key strength, the notification options, the branding settings, etc.

References: User Guide for AsyncOS 15.0 for Cisco Secure Email Gateway, page 12-4.

https://www.cisco.com/c/en/us/td/docs/security/esa/esa12-0/user_guide/b_ESA_Admin_Guide_12_0/b_ESA_Admin_Guide_chapter_01011.html

According to the User Guide for AsyncOS 12.0 for Cisco Email Security Appliances2, the order of virus scanning when multilayer antivirus scanning is configured is as follows:

• The McAfee engine scans the message first. If the McAfee engine detects a virus, the message is dropped or repaired, depending on the configuration. If the McAfee engine does not detect a virus, the message is passed to the next layer of scanning.
• The Sophos engine scans the message second. If the Sophos engine detects a virus, the message is dropped or repaired, depending on the configuration. If the Sophos engine does not detect a virus, the message is delivered to the recipient.

According to the [Cisco Secure Email User Guide], Non-Viral threat detection is a feature of Outbreak Filters that detects and blocks email messages that contain non-viral threats such as phishing, fraud, or social engineering[1, p. 25]. To use this feature, you need to enable either AntiSpam or Intelligent Multi-Scan on your Cisco Secure Email Gateway, as these features provide the necessary scanning and filtering capabilities for Non-Viral threat detection[1, p. 26].

The other options are not valid because:

• A. Non-Viral threat detection does not require Antivirus or AMP enablement to properly function. Antivirus and AMP are features that detect and block email messages that contain viral threats such as malware or ransomware[1, p. 27-28].
• B. The Outbreak Filters option Graymail Header does not affect Non-Viral threat detection. Graymail Header is an option that allows you to add a header to email messages that are classified as graymail, which are messages that are not spam but may be unwanted by some recipients, such as newsletters or promotions[1, p. 25].
• D. The Outbreak Filters option URL Rewriting does not affect Non-Viral threat detection. URL Rewriting is an option that allows you to rewrite the URLs in email messages to point to a Cisco proxy server, which can scan the URLs for malicious content and redirect the users to a warning page if needed[1, p. 25].

Content filter is a component on a Cisco Secure Email Gateway that must be configured to catch attachments, including credit card numbers, and hold them for review until further action is taken. Content filter allows you to define rules based on message content and apply actions such as quarantine, encrypt, or modify. References = [User Guide for AsyncOS 12.0 for Cisco Email Security Appliances - GD (General Deployment) - Content Filters [Cisco Secure Email Gateway] - Cisco]