The hack affects the News app built into Windows 10 and some built-in games, and can lead to unwanted purchases or virus infections
Microsoft has warned that malicious adverts have made their way into the company’s own apps built into Windows 10.
The adverts, first reported by German users, typically tell the user they have won an iPhone, or warn that the system is contaminated with malware.
Both types of messages are false and clicking on them can take users to websites that may induce unneeded purchases or infect the system with viruses.
“Currently, there is an increase in the number of malicious banner ads that open fraudulent web pages in the standard browser when starting or using apps on Windows 10,” a moderator said on the Microsoft Answers website.
Microsoft said users should simply ignore the messages and close the app in question.
Users reported the scam adverts being displayed in the News app that comes with Windows 10 as well as games built into the platform.
Such apps display advertising separately from the web browser, and as a result the malicious adverts cannot be blocked by browser-based ad blockers.
Advanced users can, however, install tools that block ads at the network level, which would also bar these fraudulent adverts.
The current campaign is unusual, however, in that the alerts are being displayed by Microsoft’s own applications, which may make them appear more authentic.