Pushing signatures to AntiVirus

When a FortiSandbox discovers a malicious file, it can create a signature that is sent to the FortiGate, to supplement the AntiVirus signature database. This signature can be used to block that file from entering the network again, and to prevent duplicates of the file being sent to the FortiSandbox in the future. This feature is enabled in an AntiVirus profile.

CLI Syntax

config antivirus profile edit “default”

set ftgd-analytics {everything | suspicious}

set analytics-db {enable | disable}

end

Files blocked by a FortiSandbox signature can be viewed and filtered for in the FortiSandbox dashboard.

In FortiOS 5.4 Beta 2, the URL feature is only available for proxy-based Web Filter profiles.

Information on the current database for both malware signatures and blocked URLs can be found by going to

System > External Security Devices.

 

FortiSandbox Integration

The following improvements have been made to how sandboxing, using either a FortiSandbox Appliance or

FortiCloud Sandboxing, integrates with a FortiGate unit.

See the Cookbook recipe Sandboxing with FortiSandbox and FortiClient.

Connecting to a FortiSandbox

1. Go to System > External Security Devices and select Enable Sandbox Inspection.

2. You can either select FortiSandbox Appliance or FortiSandbox Cloud.

3. If you select FortiSandbox Appliance, add the Server IP address.

4. Select Test Connectivity to verify that you can connect to FortiSandbox.

5. Then edit an AntiVirus profile by going to Security Profiles > AntiVirus and selecting Send Filter to

FortiSandbox Appliance for Inspection.

6. You can also select to send Suspicious Files, Executable files or all supported files.

7. Select Use FortiSandbox Database to add signatures for suspicious files found by FortiSandbox to your

FortiGate antivirus signature database.

8. Then select this Antivirus profile in a firewall policy to send files in traffic accepted by the firewall policy to

FortiSandbox.

9. You can also go to Security Profiles > Web Filter and select Block malicious URLs discovered by

FortiSandbox.

Pushing malicious URLs to Web Filtering

The malicious URL database contains all malicious URLs active in the last month. The FortiSandbox can add the URLs where any malicious files originated to a URL filter, to block these files from being downloaded again from that URL.

This feature is enabled in a Web Filter profile under Security Profiles > Web Filter > Block malicious URLs discovered by FortiSandbox.

CLI Syntax

config webfilter profile edit <profile>

config web

…

set blacklist [enable | disable]

… end

Files blocked by a FortiSandbox signature can be viewed and filtered for in the FortiSandbox dashboard. Information on the current database for both malware signatures and blocked URLs can be found by going to System > External Security Devices.

FortiSandbox Dashboard in FortiView

The FortiSandbox dashboard is available from FortiView > FortiSandbox. The dashboard shows all samples submitted for sandboxing. Information on the dashboard can be filtered by checksum, file name, result, source, status, and user name. Each entry also offers a drilldown view to show more details about a particular sample.

Web Application Firewall

Go to Security Profiles > Web Application Firewall. From here you can customize the default Web Application Firewall profile, or create new profiles, to protect against a variety of web-based threats. Web Application Firewall profiles can be created with a variety of options (Signatures and Constraints), similar to other security profiles.

You can set the Web Application Firewall to use an External Security Device, such as FortiWeb, by setting

Inspection Device to External.

Selecting External in the Web Application Firewall profile adds the following configuration to the CLI:

config waf profile edit default

set external enable end

You must add the Web Application Firewall profile to a firewall policy in order for that traffic to be offloaded to the

External Security Device for processing.

If your FortiGate or VDOM Inspection mode is set to flow-based you must use the CLI to set a Web Application Firewall profile to external mode and add the Web Applic- ation Firewall profile to a firewall policy.

 

FortiMail

To be able to offload Anti-Spam processing to a FortiMail device you should.

1. Go to System > Feature Select and turn on Anti–Spam Filter.

2. Go to System > External Security Devices, enable SMTP Service – FortiMail and add the IP address of your FortiMail device.

3. Go to Security Profiles > Anti-Spam and edit an Anti-Spam profile and set Inspection Device to External.

4. Go to Policy & Objects > IPv4 Policy, add or edit a Firewall policy, enable Anti–Spam and select the profile for which you set Inspection Device to External.

When you add this Anti-Spam profile to a firewall policy, email traffic accepted by the policy is offloaded to the

FortiMail device for processing.

If your FortiGate or VDOM inspection mode is set to flow-based you must use the CLI to set an Anti-Spam profile to external mode and add the Anti-Spam profile to a fire- wall policy.

Enabling FortiMail on the External Security Devices page adds the following configuration to the CLI:

config system wccp set service-id 52

set router-id 5.5.5.5 (the IP address of the FortiGate interface that communicates with the FortiMail)

set group address 0.0.0.0

set server-list 5.5.5.65 255.255.255.255 (the IP address of the FortiMail)

set authentication disable set forward-method GRE

set return-method GRE

set assignment-method HASH

end

 

Selecting External in the Anti-Spam profile adds the following configuration to the CLI:

config spamfilter profile edit default

set external enable end

FortiCache

To be able to offload Web Caching to a FortiCache device you should:

1. Go to System > External Security Devices, enable HTTP Service, select FortiCache and add the IP address of your FortiCache device.

2. Go to Policy & Objects > IPv4 Policy, add or edit a firewall policy and select Web Cache.

When you add web caching to a firewall policy, web traffic accepted by the policy is offloaded to the FortiCache device for processing.

Enabling FortiCache on the External Security Devices page adds the following configuration to the CLI:

config system wccp set service-id 51

set router-id 5.5.5.5 (the IP address of the FortiGate interface that communicates with the FortiCache)

set group address 0.0.0.0

set server-list 5.5.5.45 255.255.255.255 (the IP address of the FortiCache)

set authentication disable set forward-method GRE

set return-method GRE

set assignment-method HASH

end

FortiWeb

To be able to offload HTTP inspection to a FortiWeb device you should:

1. Go to System > External Security Devices, enable HTTP Service, select FortiWeb and add the IP address of your FortiCache device.

2. Go to Policy & Objects > IPv4 Policy, add or edit a firewall policy and select Web Application Firewall. When you add Web Application Firewall to a firewall policy, web traffic accepted by the policy is offloaded to the FortiWeb device for processing.

Enabling FortiWeb on the External Security Devices page adds the following configuration to the CLI:

config system wccp set service-id 51

set router-id 5.5.5.5 (the IP address of the FortiGate interface that communicates with the FortiWeb)

set group address 0.0.0.0

set server-list 5.5.5.25 255.255.255.255 (the IP address of the FortiWeb)

set authentication disable set forward-method GRE

set return-method GRE

set assignment-method HASH

end

External Security Devices

External Security Devices can be configured as means to offload processes to other devices, such as a FortiWeb, FortiCache, or FortiMail. Example processes could include HTTP inspection, web caching, and anti-spam.

To configure such a device, go to System > External Security Devices.

DNS Filter

Blocking DNS requests to known Botnet C&C addresses

A new FortiGuard database contains a list of known Botnet C&C addresses. This database is updated

dynamically and stored on the FortiGate. This database is covered by FortiGuard web filter licensing, so you must have a FortiGuard web filtering license to use this feature.

When you block DNS requests to known Botnet C&C addresses, using IPS, DNS lookups are checked against the Botnet C&C database. All matching DNS lookups are blocked. Matching uses a reverse prefix match, so all sub- domains are also blocked.

To enable blocking of DNS requests to known Botnet C&C addresses, go to Security Profiles > DNS Filter, and enable Block DNS requests to known botnet C&C.

Static URL filter

The DNS inspection profile static URL filter allows you to block, exempt, or monitor DNS requests by using IPS to look inside DNS packets and match the domain being looked up with the domains on the static URL filter list. If there is a match the DNS request can be blocked, exempted, monitored, or allowed.

If blocked, the DNS request is blocked and so the user cannot look up the address and connect to the site. If exempted, access to the site is allowed even if another method is used to block it.

DNS–based web filtering

This feature is similar to the FortiGuard DNS web filtering available in FortiOS 5.2. You can configure DNS web filtering to allow, block, or monitor access to web content according to FortiGuard categories. When DNS web filtering is enabled, your FortiGate must use the FortiGuard DNS service for DNS lookups. DNS lookup requests sent to the FortiGuard DNS service return with an IP address and a domain rating that includes the FortiGuard category of the web page.

If that FortiGuard category is set to block, the result of the DNS lookup is not returned to the requester. If the category is set to redirect, then the address returned to the requester points at a FortiGuard redirect page.

You can also allow access or monitor access based on FortiGuard category.

CLI commands

Rename webfilter-sdns-server-ip and webfilter-sdns-server-port:

config system fortiguard

set sdns-server-ip x.x.x.x set sdns-server-port 53

end

Configure DNS URL filter:

config dnsfilter urlfilter edit 1

set name “url1″ set comment ”

config entries edit 1

set url “www.google.com” set type simple

set action block set status enable

next edit 2

set url “www.yahoo.com” set type simple

set action monitor set status enable

next edit 3

set url “www.foritnet.com” set type simple

set action allow set status enable

next end

next end

Configure DNS filter profile:

config dnsfilter profile edit “dns_profile1″

set comment ” config urlfilter

set urlfilter-table 1

end

config ftgd-dns config filters

edit 1

set category 49 set action block set log enable

next edit 2

set category 71

set action monitor set log enable

next end

end

set log-all-url disable set block-action redirect set redirect-portal 0.0.0.0 set block-botnet enable

next end

Configure DNS profile in a firewall policy:

config firewall policy edit 1

set srcintf “any” set dstintf “any” set srcaddr “all” set dstaddr “all” set action accept

set schedule “always” set service “FTP”

set utm-status enable

set dnsfilter-profile “dns_profile1” set profile-protocol-options “default” set nat enable

next end

Configure DNS profile in profile group:

config firewall profile-group edit “pgrp1”

set dnsfilter-profile “dns_profile1” set profile-protocol-options “default”

next end