The world’s largest seller of cybersecurity products has a problem with its own cybersecurity.

In recent years, Microsoft Corp has been hit with a series of embarrassing hacks that have exposed corporate and government customers. Earlier this month, the US Cyber Safety Review Board issued a scathing report documenting the company’s inability to stop hackers tied to the Chinese government from pilfering the email boxes of US officials. The report’s authors called on Microsoft to institute urgent reforms.