Threat feeds

Threat feeds dynamically import an external block lists from an HTTP server in the form of a plain text file. Block lists can be used to enforce special security requirements, such as long term policies to always block access to certain websites, or short term requirements to block access to known compromised locations. The lists are dynamically imported, so that any changes are immediately imported by FortiOS.

There are four types of threat feeds:

http://example/com.url
https://example.com/url
http://example.com:8080/url

192.168.2.100
172.200.1.4/16
172.16.1.2/24
172.16.8.1-172.16.8.100
2001:0db8::eade:27ff:fe04:9a01/120
2001:0db8::eade:27ff:fe04:aa01-2001:0db8::eade:27ff:fe04:ab01

mail.*.example.com
*-special.example.com
www.*example.com
example.com

External resources file format

File format requirements for an external resources file:

• The file is in plain text format with each URL list, IP address, and domain name occupying one line.
• The file is limited to 10 MB or 128 × 1024 (131072) entries, whichever limit is hit first.
• The entry limit also follows the table size limitation defined by CMDB per model.
• The external resources update period can be set to 1 minute, hourly, daily, weekly, or monthly (43200 min, 30 days).
• The external resources type as category (URL list) and domain (domain name list) share the category number range 192 to 221 (total of 30 categories).
• There is no duplicated entry validation for the external resources file (entry inside each file or inside different files).
• If the number of entries exceed the limit, a warning is displayed. Additional entries beyond the threshold will not be loaded.

For domain name list (type = domain):

• Simple wildcards are allowed in the domain name list, for example: *.test.com.
• IDN (international domain name) is supported.

For IP address list (type = address):

• The IP address can be a single IP address, subnet address, or address range. For example, 192.168.1.1, 192.168.10.0/24, or 192.168.100.1-192.168.100.254.
• The address can be an IPv4 or IPv6 address. An IPv6 address does not need to be in [ ] format.

To determine the external resource table size limit for your device:

# print tablesize
...
system.external-resource: 0 256 512
...

For this device, a FortiGate 60E, the global limit is 512 and the limit per VDOM is 256.

Create a threat feed

To create a threat feed in the GUI:

1. Go to Security Fabric > External Connectors.
2. Click Create New.
3. In the Thread Feeds section, click on the required feed type.
4. Configure the connector settings:

   Name	Enter a name for the threat feed connector.
   URI of external resource	Enter the link to the external resource file. The file should be a plain text file with one entry on each line.
   HTTP basic authentication	Enable/disable basic HTTP authentication. When enabled, enter the username and password in the requisite fields.
   Refresh Rate	The time interval to refresh the external resource, in minutes (1 - 43200, default = 5).
   Comments	Optionally, enter a description of the connector.
   Status	Enable/disable the connector.

5. Click OK.

To create a threat feed in the CLI:

config system external-resource
    edit <name>
        set status {enable | disable}
        set type {category | address | domain | malware}
        set category <integer>
        set username <string>
        set password <string>
        set comments <string>
        *set resource <resource-uri>
        set user-agent <string>
        *set refresh-rate <integer>
        set source-ip <ip address>
        set interface-select-method {auto | sdwan | specify}
    next
end

Parameters marked with a * are mandatory and must be filled in. Other parameters either have default values or are optional.

Update history

To review the update history of a threat feed, go to Security Fabric > External Connectors, select a feed, and click Edit. The Last Update field shows the date and time that the feed was last updated.

Click View Entries to view the current entries in the list.