Article: Think Before You Click to Avoid Viruses and Scams
KEY BEST PRACTICES HIGHLIGHTED
1. Don't click e-mail attachments: Most viruses and worms arrive on your PC in the form of e-mail attachments. A few of them exploit security flaws in Windows or in your browser to launch automatically, but if you keep your programs updated, your chances of being infected via this route are slim to none. Instead of exploiting software flaws, some of the worst recent viruses rely on recipients' tossing out common sense and launching a lethal e-mail attachment. Common executable--and therefore dangerous--file-name extensions include .bat, .com, .exe, .pif, .scr, and .vbs (to read a discussion of dangerous file types, go to February's Windows Tips column). To elude the dangerous-attachment filters built into most e-mail programs, virus authors may enclose their nasty code in a .zip or .rar archive file.
2 .Don't believe the return address: Though an e-mail message may claim it's from your bank, your ISP, or even your boss, that doesn't mean it is. Spammers and virus mailers generally spoof the From address field in their messages with a legitimate address that they've stolen. You may even have received spam from yourself as a result of this clever technique.
3. Don't believe the message: To persuade you to launch a virus-laden mail attachment or provide your personal information, virus authors must earn your trust. They try to accomplish this by composing convincing-looking messages that appear to be sent from Microsoft, your ISP, or some other entity you do business with. The message may even contain links to a counterfeit version of the company's Web site, complete with genuine-looking graphics and corporate logos. Often the message laments that the company is experiencing technical problems, and that it needs you to click an executable attachment. You don't need to rely on your intuition to determine whether this message is truthful. If the message hasn't been verified by a company representative via phone or in person, it almost certainly contains a virus. Microsoft doesn't e-mail updates to its customers, and neither should your ISP.
4. Don't believe the link, either: A link in an e-mail message that claims to point to a Citibank Web site may not really go there. Devious phishing scams use the wonders of HTML to snooker you into uploading your Social Security number, PIN, credit card number, password, or other sensitive data to a scammer's Web site. A carefully crafted e-mail message purporting to be from your bank, PayPal, or some other institution (and often also containing links to the real company's Web site) warns that you must update your records there. The biggest tip-off should be this: Banks and ISPs don't lose your information and then send e-mail requests for you to reenter it online. Another tip-off is that the link text and the real underlying URL don't match. Always examine log-in Web pages and their URLs closely. If you do get hooked by creeps on a phishing expedition, notify your bank, ISP, or other institution immediately.
5. Don't download the browser code: You're browsing the Web via Microsoft's Internet Explorer when suddenly an official-looking dialog box pops up, asking if you want to download a browser plug-in. Why not? You do the same thing all the time when using Microsoft's Windows Update Web site. This one even has a digital certificate (see FIGURE 3). But if you want to avoid a flurry of pop-ups, undesirable toolbars, a home-page hijacking, or worse, don't do it. Certificates won't protect you from adware and other online annoyances borne by these ActiveX controls. If you're really unlucky, you could end up with the dreaded CoolWebSearch infestation (see last month's Internet Tips column for tools that can remove this hard-to-exterminate browser parasite).
Edited by harrywaldron, 26 June 2004 - 06:34 AM.