Symptoms of worms and trojan horse viruses in e-mail 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.