Microsoft's Azure Active Directory (AD) Premium, the software giant's cloud-based user identity management platform, is on the lookout for leaked credentials that potentially could gain hackers a foothold in their networks and lead to a bigger security headache.

David Howell, partner group program manager for the Identity and Security Services division at Microsoft, announced late Monday that his group has rolled out a new reporting option named simply Users with Leaked Credentials. Currently in preview, the feature lists users whose usernames and passwords have somehow slipped out of their grasp.

Leaked username and password combos are a major source of aggravation for businesses. "In aggregate, [tens] of millions of credentials are exposed every month," blogged Howell. "Bad actors collect, sell, and share large lists of user account credentials from these breaches."

Since folks often reuse the same password across several services, one set of credentials can act as a master key, of sorts. "Because three out of four users re-use credentials across multiple sites, there's a good chance that your users' credentials are in those lists," Howell cautioned.

To help businesses avoid spilling their secrets or other valuable information, Microsoft has been trawling the Web for the telltale signs of leaked passwords. "As part of running our consumer and enterprise identity systems, Microsoft discovers account credentials posted publically and we are making this information available to you so you can protect your enterprise when your users' account credentials are at risk," revealed Howell.

With this information in hand, Microsoft is now automatically alerting Azure AD Premium customers of the potential harm that can come to their environments. "The report surfaces any matches between these leaked credentials list and your tenant," he said.

Once clicked, the report displays "the users we've found and when we discovered the leaked credentials," Howell said. To prevent a possible breach, he advises customers to implement multifactor authentication, a feature offered in Azure AD.

Companies are increasingly relying on multifactor authentication, which augments user IDs and passwords with an additional verification method, such as a code delivered to a smartphone as an SMS or via an authentication app. In February, Apple extended its two-step authentication process to iMessage and FaceTime after rolling out the feature to iCloud.

Microsoft Azure AD has supported multifactor authentication since 2013 by way of the company's Active Authentication mobile app, a phone call or text message. Since then, the company has added the capability to several Office 365 plans.

Additional layers of password security helps, but Howell also advocates user education. "Make sure your users have read and are following your corporate IT policies," he suggested. Administrators can throw another wrench into hackers' plans by giving passwords an expiration date, forcing users to update their credentials periodically. He noted that "enforced password expiration can reduce the amount of time a leaked credential remains viable," giving intruders a limited window in which to stage an attack.