files with msi extension

I am wondering why .msi is not included on the default extensions list in the scanner settings tab. I've always used with "chooses files by extension" option but today I discovered that .msi files weren't to be scanned.

 

The scan by extension option is intended to speed things up, by only scanning files that are commonly likely to be infected. Windows Installer Files (with a .msi extention) are 'infectable' so you could add that extension to the list if you wish - that is why the list is configurable.

The list does not attempt to include every extension that is capable of becoming infected, so the line must be drawn somewhere, if you make it too long you lose any advantage of scanning by extension. I suppose it is considered statistically less likely that users will be at risk from .msi files; but of course the default setting scans all files irrespective of file type - the option is only intended for those who enjoy fiddling with such things, and I don't think they will mind adding and subtracting to and from the list!