A zero-byte file
is file that does not contain any data and is typically created when a file transfer does not complete successfully. Most files contain a number of bytes or megabytes of information which correspond to its size. A zero-byte file is essentially empty and contains no (zero) bytes.
When you are unsure about a suspicious or unknown file, rename it by adding .vir after the file's extension (i.e. badfile.dll.vir). If you receive an alert from Windows about renaming, just ignore it.
I prefer renaming instead of deleting as deletion leaves you with no option to restore if the file is later found to be legitimate. Taking no action exposes you to risk if the file is not legitimate.
Edited by quietman7, 22 February 2010 - 05:23 PM.