Virus attack on External

A virus/trojan recently attacked my computer and WD external hard drive.  I manage to save my computer and everything on it. but not my external, the problem is that the virus has which appears to have wiped out the external but when I check properties it still reveals that it is very much full,  I also did a McAfee scan and it seems to pick up everything on the external, but I can not see icons or use anything on it, please help

Try using a data recovery program and then format the HDD to use it again.

Where are we with this?