It seems that the database containing descriptions of critical and unfixed bugs and/or vulnerabilities in some of the most widely used software in the world, including the Windows operating system, was hacked back in 2013. This database is basically gold for any security researcher, regardless of the color of their hat. To know which programs fail and the preconditions for that to happen is half an exploit right there.
Microsoft discovered the database breach in early 2013 after the highly skilled hacking group Morpho a.k.a. Butterfly a.k.a. Wild Neutron broke into computers at a number of major tech companies, including Apple, Facebook, and Twitter. The group exploited a flaw in the Java programming language to penetrate employees’ Apple Macintosh computers and then use them as pivots into the company internal network.
Official sources say that the Microsoft bug database was poorly protected, with access possible via little more than a password. Four years later, we have official confirmation that it happened. To measure the breach impact, Microsoft started a study to correlate the potential flaws in their databases and subsequent attacks. The study found that the flaws in the stolen database were actually used in cyber attacks, but Microsoft argued the hackers could have obtained the information elsewhere, and that there’s “no evidence that the stolen information had been used in those breaches.”
There is really no way to know besides asking the actual hacking group, which will most likely not happen… unless they are HaD readers, in this case they can feel free to comment.