It simply means that your antivirus is not up to the mark, or may be your antivirus is not updated automatically. So first try to update your antivirus, then repeat this test. If it worked, then its ok, otherwise you have to think about changing your antivirus.

I don't know about panda antivirus, but avast is a free antivirus and I have been using it for an year and till now it has worked very good. You can download free avast antivirus from www.cnet.com. This site is considered reliable. Alternatively AVG is also a good free antivirus. But mind you before installing new antivirus, you have to uninstall your old antivirus otherwise you system may become unstable.

If you have registered windows, then it is good to allow new updates, as it may secure your system. However, over time these updates slows down your system and also they eat a lot of hard disk space. Decide what you want, speed or security.