Windows 10 S Is it completely secure? Microsoft's claim that "no known ransomware" can run on its Windows 10 S operating system does not seem to be true.
In a Friday publication by ZDNet, Hacker House security researcher Matthew Hickey said he managed to break the operating system's security in just over three hours.
Hickey was able to achieve remote management control and disable various security settings, leaving the system open for malware attacks.
Hackey started with an old technique known as DLL injection, where malicious code is executed through a process that system operations consider is not threatening. 
In this case, the violation occurred with a Word document containing the built-in macros that was needed to bypass the hacker's restrictions on Windows 10 S that are designed not to use applications that do not exist in the Microsoft Store.
After avoiding Word protection by downloading the document from a network share - instead of a link or e-mail attachment - Hickey could execute some malicious code with administrator privileges.
Using the Metasploit penetration testing software, Hickey managed to get the highest level possible accesss, with system privileges and repeated the DLL injection, to gain remote control of the machine.
After all that, as you can see Hickey could install not only some ransomware but that malware he wished
Ο computers, it was one of Microsoft's new Surface Laptops, and it was completely vulnerable.
Microsoft, meanwhile, has denied ZDNet's claim, saying it's its own essay has shown that Windows 10 S is not vulnerable to ransomware attacks.
"In early June we stated that Windows 10 S is not vulnerable to any known ransomware," said a spokesperson for companys.
And he wrote:
"We recognize that new attacks and malware are constantly emerging, so we are committed to monitoring the threat landscape and working with responsible investigators to ensure that Windows 10 continues to provide the most secure experience for our customers."
Clearly, based on Hickey's test, Microsoft's claim does not seem to be right. While Windows 10 S may be less vulnerable to such attacks because of only strictly tested software will run that has been approved by Microsoft, there are still ways that can infect computers running this operating system.
Impressing Microsoft that its operating system is invulnerable to all "known ransomware" was not so wise. Strong claims of security invite the challenge.
