Admin authentication failure detected on firewall - Fortinet
This alert is triggered whenever there are x login failure detected in y minutes for the admin/root user account on any particular Fortinet firewall.
MITRE ATT&CK Tactics
1. Change admin/root/administrator account password
2. Login into the firewall console and review change history
3. Block IP address which requested the console access
4. Consider to disable management access from the untrust zones (best practices)