Google has revealed more Windows security flaws, despite recent criticism for its last disclosure, Digital Spy reports.

Last week, Microsoft's security chief Chris Betz described Google's Project Zero as feeling "less like principles and more like a 'gotcha'".

The initiative's aim is to pinpoint security problems and inform affected companies, giving them 90 days to fix it before they reveal the flaw publicly.

On Thursday (January 15) Google exposed two new flaws, one of which allows attackers to impersonate a user on Windows 7 and 8.1, as well as decrypting and encrypting data.

The issues was actually raised on October 17, meaning Google actually went over its 90 day limit.

"Microsoft informed us that a fix was planned for the January patches but has to be pulled due to compatibility issues," a Google researcher said. "Therefore the fix is now expected in the February patches."