Block list proxies with high sign-in failure rates
Tor is open-source software used to enable anonymous communication and hide the location of end users. The software provides user anonymity, but it is often used by attackers to perform malicious activities. Okta enables admins to use Dynamic Zones to block list IPs that are categorized as Tor anonymizer proxies (Tor exit nodes).

Note
Okta is focused on the adoption of inclusive language and communication. Some long-standing industry terminology and expressions have been updated as part of this initiative. In this topic, blacklist is now referred to as block list.
HealthInsight task recommendation
Create policies to prevent or block logins from IPs with high rates of login failure. Okta provides admins with information about the IP address of each login, including proxy type.
Okta Recommends |
Create a new Dynamic Zone for IPs that are categorized as Tor anonymizer proxies and block access. See Configure a Dynamic Zone to block anonymizer proxies. |
Security impact |
Moderate |
End-user Impact |
Low When the failed sign-in rate decreases to below 50%, the HealthInsight recommendation moves from the Incomplete tab to the Complete tab. This may take a few days after you configure the block list settings. |
System Log query
Admins can run the following query in the System Log page, to view a list of all failed sign-in attempts that originated from IPs categorized as Tor anonymizer proxies.
eventType eq "user.session.start" and outcome.result eq "FAILURE" and debugContext.debugData.proxyType eq "tor"
Configure a Dynamic Zone to block anonymizer proxies
Okta enables admins to use Dynamic Zones to block list IPs that are categorized as Tor anonymizer proxies (Tor exit nodes).
- From the Admin Console, navigate to Security > Networks.
- Click Add Zone > Dynamic Zone to create a new Dynamic Zone.
- In Zone Name, enter a name for zone.
- To block list the zone, select Block access from IPs matching conditions listed in this zone.
- In IP Type, select Tor anonymizer proxy.
- Click Save.

Note
The accuracy of Tor proxy detection is dependent on a third party vendor, which is used to identify IP addresses that use Tor. The proxy type is only used to evaluate if a proxy is Tor or not.