Hackers were able to read emails and view contacts owned by people who use Microsoft email systems such as Hotmail, Outlook or MSN, it has been revealed.
Microsoft has confirmed a hack took place earlier this year that allowed a “limited” number of users accounts to be accessed by hackers.
The attackers took advantage of a customer service system which allowed them to read full emails, contacts, subject lines, recipients and folder names, according to technology news sites TechCrunch and Motherboard.
Hackers reportedly were able to access people’s email accounts through a loophole within Microsoft’s customer service system.
Microsoft denies that the attack allowed hackers to read emails, but this has been disputed by sources on other tech websites.
The tech giant said it is not known what exactly the hackers accessed and why they accessed it.
Microsoft has warned affected users that they may see an increase in spam email and recommended all users to change their passwords as a precaution.
It has also been reported that the hack could have taken place up to six months ago, but Microsoft claims the attack took place between 1 January and 28 March this year.
How can I find out if I was affected?
If you were affected you would have received an email detailing what has happened.
No enterprise customers - those paying to use the service within their company or organisation - were affected.
This means those affected are standard consumers who are most likely to use a free version of Microsoft email.