Symptoms of trajan horse and worms in email messages

When a computer virus infects e-mail messages or infects other files on a computer, you may notice the following symptoms:

The infected file may make copies of itself. This behavior may use up all the free space on the hard disk.

A copy of the infected file may be sent to all the addresses in an e-mail address list.

The computer virus may reformat the hard disk. This behavior will delete files and programs.
The computer virus may install hidden programs, such as pirated software. This pirated software may then be distributed and sold from the computer.

The computer virus may reduce security. This could enable intruders to remotely access the computer or the network.

You receive an e-mail message that has a strange attachment. When you open the attachment, dialog boxes appear, or a sudden degradation in system performance occurs.

Someone tells you that they have recently received e-mail messages from you that contained attached files that you did not send. The files that are attached to the e-mail messages have extensions such as .exe, .bat, .scr, and .vbs extensions