U.S. and global allies blame China for widespread cybercrime, including massive Microsoft Exchange hack

In a move that could have serious repercussions for the already strained U.S.-China relationship, U.S. cyber officials are blaming hackers tied to the Chinese government for one of the largest cyberattacks in U.S. history.

According to a senior administration official, the FBI and NSA have "high confidence" that hackers contracted by China's Ministry of State Security carried out the cyberattack on the Microsoft Exchange email server this spring, a breach that exposed tens of thousands of private and public U.S. entities. Victims worldwide included schools, hospitals, cities and pharmacies. White House officials say the attack was just one example of "malicious cyber activities" spearheaded by Chinese hackers, including the use of "ransomware" to threaten businesses and extort millions of dollars.