Microsoft has confirmed that some of its email services have been breached by hackers, with the contents of some user emails exposed by the attack.
The technology giant said a “limited” number of accounts had been affected by the breach, but confirmed around 6% of those involved may have seen the content of their emails become accessible to the attackers.
According to an email sent to the majority of affected users and then posted online, the firm said a Microsoft support agent’s credentials were compromised, potentially allowing unauthorised access to some account information.
For most this included a person’s email address, folder names, subject lines of emails and the names of other email addresses users communicated with between January and March this year, but not the content of emails or attachments.
However, when approached for comment on the incident, Microsoft confirmed that a small group of users had also been notified that bad actors could have gained unauthorised access to the wider contents of their emails.
The company said it was providing additional guidance and support to those users.
“We addressed this scheme, which affected a limited subset of consumer accounts, by disabling the compromised credentials and blocking the perpetrators’ access,” a Microsoft spokesman said of the incident.
Microsoft operates email services including Outlook, MSN and Hotmail.