U.S. President Joe Biden on Saturday directed U.S. intelligence agencies to investigate a cyber attack that has affected hundreds of American businesses.
The hackers, who struck on Friday, hijacked widely-used tech management software from Miami-based supplier, Kaseya.
The hackers pushed a malicious update, which spread worldwide on Saturday and has quickly become one of the largest ransomware attacks in history.
While on tour to promote a vaccination program, Biden was asked if the hack was linked to Russia.
"First of all, we're not sure who it is for certain. Number one. And what I did, I've directed the full resources of the government to assist in a response... The fact is that the director of the intelligence community gave me a deep dive on what's happened and I'll know better tomorrow. And if it is either or the knowledge of or the consequence of Russia, then I told Putin, we will respond."
Last month, the FBI blamed Russia-linked ransomware gang, REvil, for hacking an American meatpacking company.
One security firm, Huntress Labs, believes the same group is to blame for the latest attack.
The firm said it was tracking the eight service providers used to infect some 200 clients.
Meanwhile, Kaseya also launched its own supply chain investigation, with the help of top U.S. cyber officials.
Biden urged Russian President Vladimir Putin last month to crack down on cyber hacks coming from his country and warned of consequences if they continued.