Online virus and spyware scanners are applications which are downloaded only for one session. That means that after system checking they delete themselves). Usually such applications don’t need installation and don’t need a lot of free hard disk space. Frankly speaking online antivirus scanners are not assured way to protect your computer from online and virus thread. Nevertheless they can be useful. It is obvious that virus and security scanners are different. Not only user interface are different but also scanning method. This fact means that one antivirus application is able to find harmful application which can’t be detected by other antivirus applications. So if you have antivirus software of one producer it can be useful to check you system using other one. Here are some online security scanners:

Kaspersky Online Virus Scanner
It is rather interesting application because it is able not only to scan your computer for harmful applications but also to test security level in full. It shows you vulnerabilities of you systems and gives advices to fix them. If you are not very experienced user this application is for you.

Panda ActiveScan
It disinfects you computer for viruses, worms and Trojans. After pressing button you have to download 8 Mb file. Supports Panda TruPrevent scanner technology.

F-Secure Online Virus Scanner
This free service is used to find out if your computer is infected, and disinfect your computer if needed. It will automatically download the necessary components and virus databases. The size of the downloaded package is about 30 Mb.

Symantec Security Check
The main advantage of this application is simple interface. It runs rather slowly but reports you about vulnerabilities of you system.