Absolute PC Security and Privacy Michael Miller Associate Publisher: Joel Fugazzotto Acquisitions and Developmental Editor: Ellen Dendy Editors: James A. Compton, Brianne Agatep Production Editor: Mae Lum Technical Editor: James Kelly Graphic Illustrator: Tony Jonick Electronic Publishing Specialist: Franz Baumhackl Proofreaders: David Nash, Laurie O'Connell, Yariv Rabinovitch, Nancy Riddiough, Sarah Tannehill Indexer: Nancy Guenther Cover Designer and Illustrator: Richard Miller, Calyx Design Copyright © 2002 SYBEX Inc., 1151 Marina Village Parkway, Alameda, CA 94501. World rights reserved. No part of this publication may be stored in a retrieval system, transmitted, or reproduced in any way, including but not limited to photocopy, photograph, magnetic, or other record, without the prior agreement and written permission of the publisher. 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Manufactured in the United States of America 10 9 8 7 6 5 4 3 2 1 This book is dedicated to my brother-in-law Dennis and my sister-in-law Stephanie, for putting up with the rest of the family. Acknowledgments Thanks to all the Sybex staffers and freelancers who have helped to shape and shepherd this project, including but not limited to Brianne Agatep, Franz Baumhackl, Jim Compton, Ellen Dendy, Joel Fugazzotto, Nancy Guenther, Tony Jonick, Jim Kelly, Mae Lum, and my old friend Jordan Gold. Introduction I first conceived of this book when I got an e-mail from a friend—or, to be more accurate, from her e-mail program. My friend hadn’t sent the message, which had a random Word document and a virus-infected file attached; the message was sent by the computer virus that was infecting her system. It was likely, I thought, that my friend didn’t know her computer had been infected; she’s not the most technically literate person I know. (She’s a retired music teacher, not a computer geek.) So I called her, and told her that I thought she had a virus. Her immediate reaction was panic, followed by a question: Did this mean she had to throw away her computer and buy a new one? It didn’t, I replied; then I walked her through what she needed to do to remove the virus from her system. Unfortunately, I soon discovered that the steps to recovery were harder than they needed to be, and weren’t helped by the unnecessary technospeak employed by the company that supplied the chosen antivirus software. How, I wondered, was the average computer user supposed to deal with this sort of problem on their own? This incident was followed by a similar one, where my brother’s computer became infected. He is more technically literate than my music-teacher friend, and we got the problem fixed relatively quickly. He also figured out how the virus had entered his system; it was through an e-mail attachment from a friend that he had unassumingly opened a few days prior. Why had he opened the attachment, I asked—didn’t he know that’s how viruses are spread? Yes, he answered, but he’s in the habit of clicking everything he receives via e-mail, especially if it comes from someone he knows. The virus incident put my brother on alert, however, and a few weeks later I received another call from him. This time he’d received an e-mail from another friend, warning him that his system was infected with some new virus, and instructing him to delete some supposedly infected files from his system. Something about the message raised his suspicions, which prompted his call to me. I quickly got online and, after a few minutes searching (fortunately, I knew where to look) I discovered that the message my brother received was a virus hoax. There was no such virus floating around, and if he deleted the files identified in the message, he’d actually do harm to his computer system. Which caused me to think harder about the whole virus issue. All along, I’d taken it relatively lightly; after all, if you avoid opening unwanted e-mail attachments and use a good antivirus program, you’re pretty much safe from infection. But it was now blindingly obvious to me that lots of people were reckless about opening file attachments, and either didn’t use antivirus software or didn’t keep their programs up-to-date. All of which created a dangerous environment, virus-wise, for those computer users least capable of dealing with the effects of a virus infection. At the same time, I was dealing with a deluge of messages in my e-mail inbox. It seemed like every other message I was receiving was some sort of junk e-mail, trying to sell me cheap Viagra or subscriptions to some sexually explicit Web site. And if that wasn’t enough, I kept getting virus hoaxes and chain letters from friends and family, urging me to “pass this along to everyone you know.” Ugh. It seemed to me that computer viruses and e-mail spam are somehow related—at least in their ability to annoy. They are both, in their own way, intrusions into my private computing experience. And they are both annoyances that I want to eliminate. This got me thinking about a book that dealt with these “computer intrusions.” Not a book for computer geeks, filled with lots of technospeak and computer theory, but rather a book for the average user, filled with easy-to-follow instructions and practical advice. A book for my brother, my music-teacher friend, and anyone else plagued by viruses and spam e-mail. After talking to the folks at Sybex, we decided to expand on this virus-and-spam idea to include other types of both annoying and dangerous computer intrusions. The book would include information about Internet-based computer attacks, and online privacy theft, and pop- up windows, and the like. And we’d give it an umbrella title that described all the various topics covered: Absolute PC Security and Privacy. All of which explains how the book you currently hold in your hands came to be. If you use a computer in your home or small business, and you’re bothered by viruses and spam (or just worried about computer attacks and losing your online privacy), Absolute PC Security and Privacy will help you separate fact from fiction, evaluate your personal risks, and take the necessary steps to protect yourself from the most common intrusions that threaten computer users today. And, if worse comes to worst and you become a victim of some sort of Internet-based attack, you’ll also learn how to recover from the attack, and get your system back up and running. To make it easier to find specific information, this book’s 31 chapters are organized into five major sections, as follows: Part I: Computer Viruses Learn about the many different types of computer viruses—boot record, file infector, script, macro, Trojan horses, worms, and so on—and how to protect your system against their destructive payloads. Part II: Internet Attacks Discover the many ways that malicious individuals can target your computer for data theft and attack, and how to guard against such online assaults. Part III: Privacy Theft Find out how your privacy can be compromised on the Internet, and how to defend yourself against identity theft, online predators, and other threats to your privacy. Part IV: E-mail Spam Discover where all those unwanted e-mail messages in your in-box come from, and how to keep them out. Part V: Web-Based Intrusions Find out how to avoid the many major and minor annoyances you find at too many Web sites, including pop-up advertising and inappropriate content. In addition, any technical terms you may not be familiar with are likely to be listed in the book’s glossary, following the final chapter. Which brings up an important point: You don’t have to be a computer wizard to use this book. In fact, I assume that you’re a casual (Windows) PC user and aren’t interested in those overly technical solutions best suited to full-time geeks.