It’s not really surprising that scammers are taking advantage of Microsoft’s consumer release of Windows 10. According to security firm KnowBe4:
Major Operating System upgrades are usually causing confusion among end-users and the current Windows 10 upgrade is no exception. The bad guys exploit these confusions in several ways, mostly through massive phishing campaigns and with criminal call-center operations which claim to be Microsoft tech support.
Some campaigns will try to worry the user that their PC has changed somehow, causing access issues. Other phishing emails will try to lure the user with links where they can get their new no-charge version of Windows 10, or have it "attached" in a zipped file, which makes it our Scam Of The Week, because the attachment is the CBT-Locker ransomware!
KnowBe4 suggests you warn your users and offers a message to send to coworkers, friends, and family (I have edited it slightly for clarity):
Microsoft is in the process of releasing their new Windows 10 operating system. This upgrade, which promises to fix problems with earlier versions and claims to be more secure, is free. Microsoft plans to upgrade a billion personal computers which will, inevitably, cause confusion among PC users.
BE WARNED: Bad guys are trying to exploit this confusion. You might get calls from scammers who claim to be Microsoft tech support and who will try to charge you for the upgrade using your credit card. Also be very careful with any email claiming to be from Microsoft about "your Windows 10 Upgrade". Make sure that any links in the email really go to Microsoft. Better yet, do not click on any link or open any attachment, but go to the Microsoft website for more information.
Here is the link: http://www.microsoft.com/en-us/windows/windows-10-upgrade