Symptoms of infection

There are a number of symptoms indicating that your computer has been infected. If you are noticing "strange things" happening to your computer, for example:

unexpected messages or images are suddenly displayed;
unusual sounds or music played at random;
your CD-ROM tray mysteriously opens and closes;
programs suddenly start on your computer;
if Kaspersky Anti-Hacker is installed on your computer, it notifies you of attempts by some programs to connect to the Internet although you did not initiate this.

If any of the above symptoms appear, it is very likely your computer has been infected with a virus.

In addition, there are some typical symptoms indicating that your computer has been infected via email:

your friends mention that they have received messages from you but you never sent such messages;
your mailbox contains many messages without the sender's email address or header.

Note that these problems may be caused by reasons other than viruses. For example, infected messages which have your address as the sender can actually be sent from a different computer.

There are also indirect symptoms that indicate your computer has possibly been infected:

your computer freezes frequently or encounters errors;
your computer slows down when programs are started;
you are unable to load the operating system;
files and folders are suddenly missing or their content changes;
your hard drive is accessed too often (the light on your main unit flashes rapidly);
Microsoft Internet Explorer "freezes" or displays unpredictable behavior, (for example you cannot close the application window).

90% of such indirect symptoms indicate that there is a hardware or software problem, but although such symptoms are unlikely to be caused by an infection, we recommend that you perform a full scan of your computer using the default settings recommended by Kaspersky Lab experts if your encounter any of these problems.