Italy’s National Cybersecurity Agency (ACN) warned on Sunday of a large-scale campaign to spread ransomware on thousands of computer servers across Europe and North America.
France, Finland and Italy are the most affected countries in Europe at the moment, while the U.S. and Canada also have a high number of targets, the ACN warned, according to Italian news agency ANSA.
The attack targets vulnerabilities in VMware ESXi technology that were previously discovered but that still leave many organizations vulnerable to intrusion by hackers.
“These types of servers had been targeted by hackers in the past due to their vulnerability,” according to ACN. “However, this vulnerability of the server was not completely fixed, leaving an open door to hackers for new attacks.”
France was the first country to detect the attack, according ANSA.
The French cybersecurity agency ANSSI on Friday released an alert to warn organizations to patch the vulnerability.
It is estimated that thousands of computer servers have been compromised around the world, and according to analysts the number is likely to increase. Experts are warning organizations to take action to avoid being locked out of their systems.