The FBI and US Secret Service (USSS) say criminals using credentials linked to the FortiBleed campaign are locking organizations out of their Fortinet firewalls. The agencies published a joint advisory on Tuesday, citing SOCRadar's verification of more than 86,644 compromised devices across 194 countries. "Based on initial responses, some victims may get locked out of their Fortinet devices if the threat actor either deletes or changes the password for original accounts on the system," their advisory [PDF] states. "During the initial intrusion, threat actors create new accounts not previously on the device. In certain cases, threat actors delete existing accounts to block organizations from accessing affected devices and to maintain persistence on the system while attempting lateral…