The Record reported late Sunday that REvil took responsibility for the attack in a statement posted on its dark web blog, claiming it affected more than one million systems during the Kaseya incident.
"If anyone wants to negotiate about [a] universal decryptor – our price is 70 000 000$ in BTC and we will publish publicly [a] decryptor that decrypts [the] files of all victims, so everyone will be able to recover from [the] attack in less than an hour", the hacking group, believed to have links to Russia, was quoted as saying.
If honoured, the ransomware payment would be the highest ever made, the news portal added.
Kaseya, which specialises in remote management software, reported the ransomware attack last week. Shortly after, the US Federal Bureau of Investigation launched a probe into the incident.
According to recent reports, REvil alone has targeted over 200 US-based businesses in an ongoing ransomware attack.