Ripping off intellectual property.

Hackers who breached Google and other companies in January targeted source-code management systems, security firm McAfee asserted Wednesday. They manipulated a little-known trove of security flaws that would allow easy unauthorized access to the intellectual property the system is meant to protect.

The software-management systems, widely used at businesses unaware that the holes exist, were exploited by the Aurora hackers in a way that would have enabled them to siphon source code, as well as modify it to make customers of the software vulnerable to attack. It’s akin to making yourself a set of keys in advance for locks that are going to be sold far and wide.

I hear rumors that the hackers actually got into hundreds of corporations. Anyone know if that is the case?

If corporations wanted to get serious about security they'd ditch Internet Explorer, switch to Firefox or Google Chrome, and avoid Flash too. Also, upgrade to Win 7 if using Windows. XP is much less secure. To get really safe switch to Linux on a non-x86 processor.