A cyberattack that has crippled major firms, banks and airports in Europe has spread to the U.S.

According to The New York Times, the attack, revealed earlier Tuesday, claimed its first confirmed victims in the U.S.

Merck, one of the largest pharmaceutical companies in the world, confirmed its global computer networks had been hit, as did DLA Piper, the multinational law firm.

"The FBI, DHS, and sector specific agencies are working with public and private, domestic and international partners to respond to this event and provide technical information for prevention and mediation," the National Security Council said in a statement. "Although there are reportedly U.S. victims, there are no indications of risk to public safety at this time. We are taking all necessary steps to investigate, mitigate, and hold accountable those responsible."

IT security experts said the attack is likely related to a cyber disruption from May that utilized WannaCry, a bug in which a hacker demands payment in order to unlock a computer.

It is unclear who is behind the new cyberattack.

The New York Times reports the new attack was likely using a hacking tool created by the National Security Agency that was used in the WannaCry attacks. The tool, called Eternal Blue, was among dozens believed to be stolen from the NSA and leaked online last April by a group known as the Shadow Brokers.