Windows 7 still allows unsafe files to be disguised as security files.

F-Secure has discovered the first security issue of Windows 7 system. This problem is also a long-standing problem in Windows systems, such as NT, 2000, XP and Vista. In the browser, the browser can be set to hide extensions of known file types. Many virus makers use this feature to entice users to click on executable files that appear to be document files. For example, they will "VIRUS.EXE" files. Renamed "VIRUS.TXT.EXE", Windows will hide the ".EXE" suffix. The virus author may also modify the file icon to a text file icon. This problem has not been resolved in Windows 7.