As we reported yesterday, the source code for several Microsoft Windows 10 builds and tools was leaked online. According to the company, the potential damage from the breach may be limited.
Windows 10 the leak:
The Register first reported the leak on June 23, and reported that up to 32TB of “official and non-public (Windows 10) installation images” were uploaded to BetaArchive.com. (BetaArchive calls itself “the community for beta collectors” and “one of the largest Beta & Abandonware repositories!”) 
The leaked code may date back to March 2017, according to Reg, and is reportedly part of Microsoft's Shared Source Kit. It includes source code for core Windows 10 drivers, PnP code, USB and WiFi stacks, storage drivers, and ARM OneCore kernel.
Builds of Windows 10 and Windows Server 2016 were never released to the public. Internal builds were created by the Windows team for Microsoft engineers only for testing and debugging purposes that are typically not found in public releases.
This software includes, for example, pre-release versions of Windows 10 “Redstone” and 64-bit ARM builds of Windows. Many of the versions that leaked online have been recalled by Microsoft due to the Secure Boot mechanism.
In the tweet below, you can see images of the leaked files
Windows 10 leak: Beta Archive has removed the private MS files from its FTP. Here's examples of non-public stuff that was dumped online pic.twitter.com/WULYM7me7U
— The Register (@TheRegister) June 23, 2017
BetaArchive has already downloaded 1.2 TB of Windows 10 code according to its owner, according to the initial report.
“The “Shared Source Kit” folder existed on the FTP until the Register article was published. We have removed it from the FTP and our lists.”
Microsoft, for its part, confirmed the leak, stating:
“Our review confirms that these files are part of the source code from the Shared Source Initiative, and are used by OEMs and partners.”
Through the Shared Source Initiative, Microsoft licenses the source code for various of its products to certain "specialized" customers, governments, and partners for debugging purposes.
Windows 10 leak: The counterargument
It should be mentioned that Windows 10 Shared Source Kit means the source code that is shared.
Another post about the leak from The Verge claims that “most of the collection (of leaked files) has been available for months or even years.”
The publication from the UK's Reigster claims that 32TB of data was leaked, but The Verge claims that most of that 32TB has been online for years and that the new leak is actually much smaller, coming in at just 1.2GB.
Reigster claims that this leak is even bigger than the famous 2004 leak of Windows 2000 source code, but The Verge disagrees.
The Verge appears to be correct, as the leak of this particular source code appears to be minor and uninteresting, as it includes files related to Windows 10's USB, storage, and Wi-Fi drivers only.
These files had already been shared by Microsoft with computer manufacturers and other partners (OEMs, businesses, and governments) while the 2004 leak was massive.
I don't think anyone would argue that USB drivers are that important. The only important thing that seems to be in the leak is the ARM OneCore kernel, but if it's part of the Windows 10 Shared Source Kit, it's already Shared by the company itself.
The Verge is trying to connect a related incident: Yesterday, two men were arrested in the United Kingdom who had gained unauthorized access to Microsoft's network.
These two men were apparently collecting internal Windows 10 Insider Preview builds that were never released to external testers and then releasing them online. Most of the 32GB of leaked Windows 10 builds were apparently these builds, not their source code.
We'll probably find out what really happened in the coming days. Of course, we don't expect to find out what happened from Microsoft itself, as a possible leak of the Windows 10 source code would mean the end of the much-hyped operating system. Unless the company makes it Open Source.
I might then reinstall Windows on my computers.
