14 DAY TRIAL // Microsoft describes Windows 10 S as the most secure version of its operating system, emphasizing that the simple fact that Win32 software is blocked by default also means that the majority of threats are infective, including here the most common forms of malware.
And while security of Windows 10 S is indeed increased thanks to the Windows Store app limitation, a recent research has shown that this operating system can also be compromised using one of the oldest tricks in the books.
ZDNet reports of a test performed with security researcher Matthew Hickey who discovered that Microsoft Office macros can still be used to compromise a Windows 10 S quite easily. Macros have long been one of Microsoft’s main concerns in terms of Office security, and even with the release of Windows 10 S, the company still hasn’t managed to address it.
The macro-based exploit is possible with the Windows Store version of Office, which can be downloaded and installed on Windows 10 S as well. Using a malicious macro included in a document, the researcher was able to carry out a reflective DLL injection attack, getting around the Windows Store app restriction using a whitelisted process, in this case Word 2016.
Microsoft not too worried
To protect users against malicious macros, Microsoft has implemented the protected view, which means documents can be opened, but without running any macros or triggering downloads from the Internet. This is why the security researcher bypassed protected view by downloading the Word document from a network share, and cybercriminals could do the same by first compromising a different system in the network.
Macros aren’t launched automatically when opening documents, but using the document contents, users can be tricked into allowing them to run, which in the end could provide cybercriminals with full control over the vulnerable systems.
Microsoft itself doesn’t seem to be too concerned with this working vulnerability, saying instead that it’s working to boost security of Windows 10 by keeping an eye on the new threats.
“We recognize that new attacks and malware emerge continually, which is why we are committed to monitoring the threat landscape and working with responsible researchers to ensure that Windows 10 continues to provide the most secure experience possible for our customers,” Microsoft said.