A gang of cyber hackers from Russia attacked a supply-chain software company that works with dozens of U.S. businesses, and is now demanding a $70 million ransom.

The FBI says a group called REvil, based in Russia, made the ransom demand, which is one of the largest cyber attacks of its kind, according to CBS News. It’s the same group of criminal hackers who attacked a meat-packing company over the Memorial Day weekend.

When asked about this latest attack, President Biden said the U.S. did not know yet if the Russian government was involved in it.

Biden also reiterated the warning he gave Vladimir Putin at their summit last month about what would happen if Russia continues its cyber-attacks.

“If it is, either with the knowledge of and or a consequence of Russia, then I told Putin we will respond…”

The cyber-attack occurred sometime Friday when the hackers hijacked software from Kaseya, a supplies of management software technology. Essentially, the criminals overrode a tool used by companies that manage technology at smaller businesses. They then encrypted the files of those providers’ customers.

In an update posted on its website late Sunday night, Kaseya said its IT group managed to contain the attack to what it calls a “very small number of on-premises customers only.”

Still, cyber-crime experts say this type of attack exemplifies how cyber-attacks are escalating. Instead of just targeting a single company, such as the recent hit on the Colonial Pipeline Co., going after a company like Kaseya, which provides supply-chain software support, hackers can cripple a multitude of businesses in various industries. The attack on Kaseya, for instance, impacted a number of financial services firms as well as the Sweden-based grocery-store chain, Coop.

The Department of Homeland Security agrees that cyber crime is a growing problem. CBS News obtained documents that show the DHS analysts warning that ransomware attacks in the U.S. are likely to increase in the near and long-term.

Experts in the cyber security field say hacker groups like REvil often operate out of Russia because there is little threat of oversight or crackdown from Putin’s government.

Meanwhile, because this attack happened over a holiday weekend, many more businesses may have not yet realized they have been impacted.