The Italian premier's office said on Sunday night the attacks affecting computer systems in the country involved "ransomware already in circulation" in a product made by cloud technology provider VMware.

There have been reports that servers were compromised in other European countries such as France and Finland as well as the United States and Canada.

A technical bulletin from a French cybersecurity agency said the attack campaigns target VMware ESXi hypervisors, which are used to monitor virtual machines.

Palo Alto, California-based VMware fixed the bug back in February 2021 but the attacks are targeting older, unpatched versions of the product.

The company said in a statement Sunday that its customers should take action to apply the patch if they have not already done so.

"Security hygiene is a key component of preventing ransomware attacks," it said.

The US Cybersecurity and Infrastructure Security Agency said on Sunday it is "working with our public and private sector partners to assess the impacts of these reported incidents and providing assistance where needed."

The problem attracted particular public attention in Italy on Sunday because it coincided with a nationwide internet outage, affecting operator Telecom Italia, which interfered with streaming the Spezia v. Napoli soccer match but appeared largely resolved by the time of the later Derby della Madonnina between Inter Milan and AC Milan.

It was unclear whether the outages were related to the ransomware attacks.

Australian Associated Press