Google
A Google sign is seen during the WAIC (World Artificial Intelligence Conference) in Shanghai, China, Sept. 17, 2018. REUTERS/Aly Song/File Photo

At least two U.S. states are investigating a breach at Alphabet Inc's Google that may have exposed private profile data of at least 500,000 users to hundreds of external developers.

The investigation follows Google's announcement on Monday that it would shut down the consumer version of its social network Google+ and tighten its data-sharing policies after a "bug" potentially exposed user data that included names, email addresses, occupations, genders and ages.

"We are aware of public reporting on this matter and are currently undertaking efforts to gain an understanding of the nature and cause of the intrusion, whether sensitive information was exposed, and what steps are being taken or called for to prevent similar intrusions in the future," Jaclyn Severance, a spokeswoman for Connecticut Attorney General George Jepsen, told Reuters in an email.

The New York Attorney General's office also said it was looking into the breach.

Google said the issue was discovered and patched in March as part of a review of how Google shares data with other applications. No developer exploited the vulnerability or misused data, the company's review found.

The Wall Street Journal reported on Monday that Google opted not to disclose the security issue due to fears of regulatory scrutiny, citing unidentified sources and a memo prepared by Google's legal and policy staff for senior executives.

Earlier on Tuesday, Ireland's data protection regulator said it would seek more information from Google regarding the breach.

"The Data Protection Commission was not aware of this issue and we now need to better understand the details of the breach, including the nature, impact and risk to individuals and we will be seeking information on these issues from Google," the regulator said.

Google does not yet have a lead EU Supervisory authority, as the breach apparently happened before the EU's new privacy law, the General Data Protection Regulation, was implemented. As a result, all EU data protection authorities have jurisdiction to engage with Google on the breach.

Google did not immediately respond to a Reuters request for comment.

(Reporting by Angela Moon in New York and Arjun Panchadar in Bengaluru; Editing by Shailesh Kuber and Dan Grebler)

-Reuters