The technology giant revealed Friday regarding the attacks targeted 7 companies in U.S., Canada, France, India, and South Korea.
But since it blocked “majority” of the attacks, Microsoft acknowledged that some were successful.
Microsoft revealed it had notified affected companies but declined to consider them.
“We think these attacks are unconscionable and should be condemned by each of the civilized society,” said Tom Burt, Microsoft’s customer security and chief, in a post.
The technology giant blamed attacks on three distinct hacker groups. The Russian group, which Microsoft calls Strontium, is better known as APT28 or Fancy Bear, used password spreading attacks to target their victims.
It that which often involves recycled passwords.
Fancy Bear could be best known for its disinformation and hacking operations in the run-up of 2016 presidential election.
But the group has also blamed for a string of other high-profile attacks against media outlets and businesses.
The other two groups backed by the North Korean regime, one of which Microsoft calls Zinc and better known as the Lazarus Group, used targeted spearphishing emails disguised as recruiters in an effort to steal passwords from their victims.
Lazarus blamed for the Sony hack in 2016 and the WannaCry ransomware attack in 2017, and other malware driven attacks.
But little is known about other North Korea-backed hacker group, which Microsoft calls Cerium.
Microsoft said the group even used targeted spearphishing emails misleading as representatives from the WHO, charged with coordinating the effort to combat COVID-19 pandemic.
A Microsoft spokesperson acknowledged it was the first time the company referenced Cerium, but the company did not offer more.
This is the latest effort by hackers is that they are trying to exploit the COVID-19 pandemic for their own goals.
This year, the FBI and Homeland Security has warned the hackers if the practise remains the same to steal coronavirus vaccine research.