Hackers linked to Russian intelligence services are trying to steal information about coronavirus vaccine research in the U.S., Canada and the U.K., security officials said.

Officials said a group known as APT29 — also known as “Cozy Bear” — was likely to blame for the attack. They said the group, which is believed to be associated with Russian intelligence, used spear phishing and custom malware to target vaccine researchers.

The U.S. Department for Homeland Security, the Cybersecurity Infrastructure Security Agency, the National Security Agency, Canada’s Communications Security Establishment and the U.K.’s National Cyber Security Centre joined forces in accusing Russia of the hacking campaign.

“It is completely unacceptable that the Russian Intelligence Services are targeting those working to combat the coronavirus pandemic”, U.K. Foreign Secretary Dominic Raab said in a statement. “While others pursue their selfish interests with reckless behaviour, the U.K. and its allies are getting on with the hard work of finding a vaccine and protecting global health”.

Kremlin spokesman Dmitry Peskov rejected the allegations. He said that Russia had nothing to do with alleged cyberattacks on pharmaceutical firms and research institutions, adding that the claims were not backed by proper evidence.