A malicious email is any piece of email that was sent with the intention of disrupting your computer or network. The computer user installs the virus or trojan by clicking on an HTML link. It is called malicious because it becomes aggressive once it is installed. Some malicious emails can cause your computer to stop functioning and may be difficult to remove.
How It Circulates
Malicious email is commonly distributed by infected computers. When your computer is infected, the malicious script will scan your contacts list and automatically send itself to some or all of the people you exchange mail with. This increases the success rate because the people in your contacts list are less likely to question the content of the mail. As each new person unsuspectingly clicks on the HTML portion of the email, the cycle begins all over again.
Malicious email could contain a variety of threats, including the base code needed for a virus loader. When you click on the link, a very short program runs that installs a virus into your machine. You may not detect anything happening at all, but the next time your computer starts it will activate the virus code, mass emailing your contacts or causing your computer to malfunction.
Clicking on a link in an HTML email could start a Trojan installation. A Trojan is a program that looks legitimate but has malicious code hidden inside. Trojans can be difficult to remove because they will actively resist removal attempts. For example, a Trojan may run two programs at startup: The first performs the programmed mischief, and another hidden program guards it, possibly even creating multiple installations with random names. A Trojan can be used to install other types of malicious software, even additional Trojans.
Spyware is a program that monitors your activity and send reports to the instigating agency. Spyware is commonly installed by a Trojan, usually while viewing or installing a legitimate piece of software. Information gathered by spyware can range from the types of programs you use to credit card or other information that can be used for identity theft. Because spyware programs operate in the background, they can reduce your computer speed dramatically.
Play It Safe
The best defense against malicious email is to avoid opening anything you cannot verify. If the mail comes from a trusted source, ask him about any unexpected email attachments. If you cannot verify the source, delete the email. Contrary to popular myth, malicious email cannot cause any harm until you click on a link to install it. Simply reading the message text will not activate harmful activity, so it is OK to look at the message as long as you do not click on its contents.
- Photo Credit Medioimages/Photodisc/Photodisc/Getty Images
How to Check a Link for Viruses
In our age of viruses and malware, if you are ever tempted to click on a strange link, it's better to find...