Panda does not encrypt its' virus signatures and therefore most AVs see the 'ignature" as a valid virus.
I don't think we ever were able to determine why the do not encrypt them.
I think it may have something to do with the way the file is packed/unpacked.
Here is the list of Panda Antivirus files that avast! detects as infected:
IMSCAN.DLL
PAVDLL.DLL
PAV.SIG
APVXD.VX2
APVXD.VXD
Check the Avast website for more info on this Panda thing.
So then, why DOES everyone use it?