Alleged Windows XP source code appears online

Files that are claimed to be source code for Microsoft products have appeared on the Internet, including the source code for Windows XP. Researchers claim that the source code has been around for years.

The alleged Windows XP source code has appeared on storage service Mega. It is a 2.93GB zip file named nt5src. Windows NT 5.0 appeared as Windows 2000, NT 5.1 and 5.2 were Windows XP versions. It is not yet clear whether it actually concerns the source code of the twenty-year-old operating system. Claim on Twitter security researchers that the source code had been circulating on underground forums for years and that it is now about mainstream availability.

The file was made part of a collection of files with a size of 43GB and containing source code of various Microsoft products by a Reddit user, Bleeping Computer describes. Microsoft has not yet responded to the claims of source code leaks.

Microsoft has had to deal with source code leakage before. Earlier this year, the alleged source code of the software for the original Xbox and Windows version NT 3.5 appeared on the Internet. Parts of the source code of Windows 10 also appeared online, Microsoft had to admit in 2017.

Malicious people can use the source code to find undiscovered leaks in the software, although the share of users of XP is only 0.82 percent according to Statcounter, which makes it questionable whether criminals will still take that trouble. The source code could further aid in the development of the open source operating system ReactOS, which strives for compatibility with Windows, but does not use Windows source code itself.