, Russian security experts have shown how a rogue file call to the Windows Master File Table on an NTFS disk can soak up system resources and end up leaving your computer pretty much unusable, eventually leading to a crash.
All that it takes is a visit to a page showing an image coded in a certain way, and your woes begin. Your machine isn't actually hacked or exposed, but it's an annoying little bug that Microsoft will no doubt be scrambling to fix.
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Windows 7 and Windows 8 (and 8.1) are the OSes affected, along with Windows Vista which is no longer supported by Microsoft. If you're using any browser in , or Google Chrome on any OS, you should be safe.
While the bug has been reported to Microsoft, we haven't heard any official acknowledgement of the problem or any timescale on when a fix might be pushed out through the usual channels.
As always, keep your browser and your operating system right up to date to minimize the risk of getting hit by these sort of issues. No one seems to have tried to use the trick yet out in the wild, but if you do notice problems, a simple reboot should fix it.