Every anti virus is designed to detect the virus and take some action. Usually they can be set to automatically delete them, allow or block the access to the files, leaving the infected files where they are, or maybe to quarantine them.

Yes, that’s the theory.  The reality is that if in the virus definitions the signatures of a particular virus are not included, this virus and its infected files are not recognized by the antivirus. That’s important to set the antivirus to constantly update the virus definitions, every day or maybe even several times in a day, since some antiviruses use definitions which are build 3-4-5 times a day.

As I said one of the problem is the signature of a virus missing in the updates. Another risk… better say frequent issue… is the fact that the autoprotect of an antivirus doesn’t work fine, or doesn’t work at all. It happens many times and you probably don’t know it. The autoprotect stops working, often because of a corruption of the virus definitions, also called signatures.

The virus definitions can get currupted for several reasons, the most common one is the corruption of the antivirus during the installation. Usually the signatures are downloaded via TCP, so we know that TCP is a reliable protocol, not like UDP, so we can assume that the definitions arrive to the computer ina good state The corruption can happen during the installation or during the redistribution from an Antivirus Server to the Antivirus Clients.

One way to test your antivirus is the EICAR malware test file. You can download it from here. Eicar is a secure file that is created to test the antiviruses scan engines. Even if you double click on it on a computer without antivirus, you won’t get any kind of infection. You will be safe.

To test your antivirus there is also another way, this way is lessa safe and insecure. How you can imagine from the titlle, you can test the antivirus with REAL VIRUSES. You can download them from here: http://www.mediafire.com/?9nyjx1sll9d

It has been tested with NOD32 and it detects 100% of them!!

If you have any issues or questions about viruses or you want help cleaning your PC from an infection, you can write in our forum www.security-exchange.net

Any question? You need our FAST help? Go to our forum and as for FREE!