No doubt, May was a bad month for Windows 7 users. Widely widespread WannaCry ransomware hit computers and machines running Window 7 while a new bug discovered last week is able to slow down and crash computers running Window 7 and Window 8.
As strange as it sounds, four characters is enough to trigger that particular vulnerability, which can slow down your system, or more often, lead to a blue screen of death. So if you do, Windows 7 & Windows 8 users (but also Vista users, if there are any out there), do not try to open any file with the filename "$ MFT".
This filename is typically intended for special metadata files in the Windows NTFS filesystem, and when you try to open a file that includes these characters as part of the filename or directory path of the file (eg C: \ $ MFT \ image) this will crashes your computer, according to Ars Technica.
The bug does not appear to affect Window 10, and Microsoft is already aware of the issue and a corresponding update is pending for its fix.
Many of you can remember one of the most disturbing or many funny bugs of Windows 95 and 98: specially configured file names could cause the operating system to crash. Malicious users could use this bug to attack other users' machines by using one of the special file names as image sources. The browser tried to access this file and the Windows collapsed.
As it turns out Window 7, 8.1 and Vista are affected by a similar kind of error.
The Verge site successfully tested the error on a Window 7 computer with a default Internet Explorer browser. Using a file name with path "c: \ $ MFT \ 123" in an image of a web site, the test caused a machine to slow down to the point where the computer needed to restart. Some machines may eventually have a blue screen of death, as the filesystem locks in that file and all other applications cannot access files.