John received an e-mail from a friend, with a link to a website to view an interesting video. She clicked the link. Within a few days, her computer was behaving strangely—the Internet connection had become slow; even checking e-mail was difficult. Pressing Ctrl+Alt+Del to see running programs didn’t show any unusual activity. Looking at the list of installed programs didn’t help either.
Clicking the link installed a Trojan on John’s machine. In all likelihood, her friend would not even know that such an e-mail had been sent—many Trojans, when they infect a computer, send e-mail to all contacts in the user’s Address Book.
The Trojan could do one of several things on John’s machine. It could install programs such as keyloggers, which record keyboard strokes. Keyloggers can steal usernames, passwords and other sensitive information from a PC. It could record her John’s behavior and install an adware program to show her context-sensitive ads. Or it could even turn her machine into a ‘zombie’ computer, which could then be used to send spam, viruses or worms to thousands of computers.
It is difficult to remove Trojans and contain the damage that they might do to your machine. They can come hidden in anything—games, screensavers, images, links are some of the ways they sneak in. Therefore, be very careful in opening attachments or clicking links, even if they seem to be coming from your friends. E-mail attachments are the most favored route for spreading viruses and worms. Before you open it, it’s better to check with your friend if she has actually sent such an e-mail or not.
Via : Msn
Via : Msn