Can virus detection be triggered just by a filename?

Hi,

We got a notification of a virus as follows: Virus/spyware 'Mal/EncPk-AJO' has been detected in "C:\Windows\Temp\JET6FD2.tmp".

Is it possible that it got labelled as a virus just on the filename?

Wondered because it was in use by the Sophos firewall service, and although that filename is associated with a virus it’’’’s detection hasn’’’’t been updated since October 2013, and there are a lot of JETxxxx.tmp files with a new one appearing to get created each time the firewall service starts.

So is this just a false positive down to luck?

Thanks