Norton didn't detect this???

ok I ran a malewarebytes full system  scan. It detected some for of koobface virus located in a program folder called mindscape which I beleive is some type of program that does fonts and all here is the path

  C:\Windows\Programfiles\Mindscape

 

It detected it as a dll file I think it was HUBER.DLL  anyway after the malewarebytes scan detected it, I went to that folder and scanned the dll item with my Norton Antivirus (up to date defs). The Norton scan did not detect this as a virus

 

Could it be the malewarebytes scan detected this as a form of the kkobface worm but that it was a false positive?

The file has been in place since April 2008 and there were no changes to the file recently when I checked the properties.

 

I do Norton AV scans Full System several times a week and have done so for years. So it concerns/confuses me why Norton never detected it, thats why I wonder if it was a false positive on malewarbytes part.

 

No to complicate matters, after the Malewarebytes scan when I indicated I wanted to delete this file, malewarebytes program indicated that I needed to restart my computer. I DID NOT wan to restart. So like a fool, I went into C:\Windows\Programfiles\Mindscape and just deleted the whole mindscape folder, sent it to the recycle bin and then deleted it from the recycle bin.

So I ran another malewarebytes scan (quick scan this time) and nothing came up. No I went ahead and deleted the malewarebytes program from my computer

 

So my questions are

1. Why would Norton not have detected this before?

2. Can it be a false positive from malewarebytes?

3. By sending the item to the recycle bin and deleting it from there, would that most likely have removed it from my system?

4. By deleteing the malewarebytes program from my computer, would that have taken th offending item with it?

5. thoug the malewarebytes program is not on my computer now, if I restart my computer at this point, would that remove the item?