Entries Tagged "antivirus"

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Do We Really Need a Security Industry?

Last week I attended the Infosecurity Europe conference in London. Like at the RSA Conference in February, the show floor was chockablock full of network, computer and information security companies. As I often do, I mused about what it means for the IT industry that there are thousands of dedicated security products on the market: some good, more lousy, many difficult even to describe. Why aren’t IT products and services naturally secure, and what would it mean for the industry if they were?

I mentioned this in an interview with Silicon.com, and the published article seems to have caused a bit of a stir. Rather than letting people wonder what I really meant, I thought I should explain.

The primary reason the IT security industry exists is because IT products and services aren’t naturally secure. If computers were already secure against viruses, there wouldn’t be any need for antivirus products. If bad network traffic couldn’t be used to attack computers, no one would bother buying a firewall. If there were no more buffer overflows, no one would have to buy products to protect against their effects. If the IT products we purchased were secure out of the box, we wouldn’t have to spend billions every year making them secure.

Aftermarket security is actually a very inefficient way to spend our security dollars; it may compensate for insecure IT products, but doesn’t help improve their security. Additionally, as long as IT security is a separate industry, there will be companies making money based on insecurity — companies who will lose money if the internet becomes more secure.

Fold security into the underlying products, and the companies marketing those products will have an incentive to invest in security upfront, to avoid having to spend more cash obviating the problems later. Their profits would rise in step with the overall level of security on the internet. Initially we’d still be spending a comparable amount of money per year on security — on secure development practices, on embedded security and so on — but some of that money would be going into improving the quality of the IT products we’re buying, and would reduce the amount we spend on security in future years.

I know this is a utopian vision that I probably won’t see in my lifetime, but the IT services market is pushing us in this direction. As IT becomes more of a utility, users are going to buy a whole lot more services than products. And by nature, services are more about results than technologies. Service customers — whether home users or multinational corporations — care less and less about the specifics of security technologies, and increasingly expect their IT to be integrally secure.

Eight years ago, I formed Counterpane Internet Security on the premise that end users (big corporate users, in this case) really don’t want to have to deal with network security. They want to fly airplanes, produce pharmaceuticals or do whatever their core business is. They don’t want to hire the expertise to monitor their network security, and will gladly farm it out to a company that can do it for them. We provided an array of services that took day-to-day security out of the hands of our customers: security monitoring, security-device management, incident response. Security was something our customers purchased, but they purchased results, not details.

Last year BT bought Counterpane, further embedding network security services into the IT infrastructure. BT has customers that don’t want to deal with network management at all; they just want it to work. They want the internet to be like the phone network, or the power grid, or the water system; they want it to be a utility. For these customers, security isn’t even something they purchase: It’s one small part of a larger IT services deal. It’s the same reason IBM bought ISS: to be able to have a more integrated solution to sell to customers.

This is where the IT industry is headed, and when it gets there, there’ll be no point in user conferences like Infosec and RSA. They won’t go away; they’ll simply become industry conferences. If you want to measure progress, look at the demographics of these conferences. A shift toward infrastructure-geared attendees is a measure of success.

Of course, security products won’t disappear — at least, not in my lifetime. There’ll still be firewalls, antivirus software and everything else. There’ll still be startup companies developing clever and innovative security technologies. But the end user won’t care about them. They’ll be embedded within the services sold by large IT outsourcing companies like BT, EDS and IBM, or ISPs like EarthLink and Comcast. Or they’ll be a check-box item somewhere in the core switch.

IT security is getting harder — increasing complexity is largely to blame — and the need for aftermarket security products isn’t disappearing anytime soon. But there’s no earthly reason why users need to know what an intrusion-detection system with stateful protocol analysis is, or why it’s helpful in spotting SQL injection attacks. The whole IT security industry is an accident — an artifact of how the computer industry developed. As IT fades into the background and becomes just another utility, users will simply expect it to work — and the details of how it works won’t matter.

This was my 41st essay for Wired.com.

EDITED TO ADD (5/3): Commentary.

EDITED TO ADD (5/4): More commentary.

EDITED TO ADD (5/10): More commentary.

Posted on May 3, 2007 at 10:09 AMView Comments

Targeted Trojan Horses Are the Future of Malware

Good article:

Security technology can stop common attacks, but targeted attacks fly under the radar. That’s because traditional products, which scan e-mail at the network gateway or on the desktop, can’t recognize the threat. Alarm bells will ring if a new attack targets thousands of people or more, but not if just a handful of e-mails laden with a new Trojan horse is sent.

“It is very much sweeping in under the radar,” said Graham Cluley, a senior technology consultant at Sophos, a U.K.-based antivirus company. If it is a big attack, security companies would know something is up, because it hits their customers’ systems and their own honeypots (traps set up to catch new and existing threats), he said.

Targeted attacks are, at most, a blip on the radar in the big scheme of security problems, researchers said. MessageLabs pulls about 3 million pieces of malicious software out of e-mail messages every day. Only seven of those can be classified as a targeted Trojan attack, said Alex Shipp, a senior antivirus technologist at the e-mail security company.

“A typical targeted attack will consist of between one and 10 similar e-mails directed at between one and three organizations,” Shipp said. “By far the most common form of attack is to send just one e-mail to one organization.”

Posted on October 17, 2006 at 7:04 AMView Comments

Why the Top-Selling Antivirus Programs Aren't the Best

The top three antivirus programs — from Symantec, McAfee, and Trend Micro — are less likely to detect new viruses and worms than less popular programs, because virus writers specifically test their work against those programs:

On Wednesday, the general manager of Australia’s Computer Emergency Response Team (AusCERT), Graham Ingram, described how the threat landscape has changed — along with the skill of malware authors.

“We are getting code of a quality that is probably worthy of software engineers. Not application developers but software engineers,” said Ingram.

However, the actual reason why the top selling antivirus applications don’t work is because malware authors are specifically testing their Trojans and viruses to make sure they can bypass these applications before releasing them in the wild.

It’s interesting to watch the landscape change, as malware becomes less the province of hackers and more the province of criminals. This is one move in a continuous arms race between attacker and defender.

Posted on August 2, 2006 at 6:41 AMView Comments

Who Owns Your Computer?

When technology serves its owners, it is liberating. When it is designed to serve others, over the owner’s objection, it is oppressive. There’s a battle raging on your computer right now — one that pits you against worms and viruses, Trojans, spyware, automatic update features and digital rights management technologies. It’s the battle to determine who owns your computer.

You own your computer, of course. You bought it. You paid for it. But how much control do you really have over what happens on your machine? Technically you might have bought the hardware and software, but you have less control over what it’s doing behind the scenes.

Using the hacker sense of the term, your computer is “owned” by other people.

It used to be that only malicious hackers were trying to own your computers. Whether through worms, viruses, Trojans or other means, they would try to install some kind of remote-control program onto your system. Then they’d use your computers to sniff passwords, make fraudulent bank transactions, send spam, initiate phishing attacks and so on. Estimates are that somewhere between hundreds of thousands and millions of computers are members of remotely controlled “bot” networks. Owned.

Now, things are not so simple. There are all sorts of interests vying for control of your computer. There are media companies that want to control what you can do with the music and videos they sell you. There are companies that use software as a conduit to collect marketing information, deliver advertising or do whatever it is their real owners require. And there are software companies that are trying to make money by pleasing not only their customers, but other companies they ally themselves with. All these companies want to own your computer.

Some examples:

  • Entertainment software: In October 2005, it emerged that Sony had distributed a rootkit with several music CDs — the same kind of software that crackers use to own people’s computers. This rootkit secretly installed itself when the music CD was played on a computer. Its purpose was to prevent people from doing things with the music that Sony didn’t approve of: It was a DRM system. If the exact same piece of software had been installed secretly by a hacker, this would have been an illegal act. But Sony believed that it had legitimate reasons for wanting to own its customers’ machines.
  • Antivirus: You might have expected your antivirus software to detect Sony’s rootkit. After all, that’s why you bought it. But initially, the security programs sold by Symantec and others did not detect it, because Sony had asked them not to. You might have thought that the software you bought was working for you, but you would have been wrong.
  • Internet services: Hotmail allows you to blacklist certain e-mail addresses, so that mail from them automatically goes into your spam trap. Have you ever tried blocking all that incessant marketing e-mail from Microsoft? You can’t.
  • Application software: Internet Explorer users might have expected the program to incorporate easy-to-use cookie handling and pop-up blockers. After all, other browsers do, and users have found them useful in defending against Internet annoyances. But Microsoft isn’t just selling software to you; it sells Internet advertising as well. It isn’t in the company’s best interest to offer users features that would adversely affect its business partners.
  • Spyware: Spyware is nothing but someone else trying to own your computer. These programs eavesdrop on your behavior and report back to their real owners — sometimes without your knowledge or consent — about your behavior.
  • Internet security: It recently came out that the firewall in Microsoft Vista will ship with half its protections turned off. Microsoft claims that large enterprise users demanded this default configuration, but that makes no sense. It’s far more likely that Microsoft just doesn’t want adware — and DRM spyware — blocked by default.
  • Update: Automatic update features are another way software companies try to own your computer. While they can be useful for improving security, they also require you to trust your software vendor not to disable your computer for nonpayment, breach of contract or other presumed infractions.

Adware, software-as-a-service and Google Desktop search are all examples of some other company trying to own your computer. And Trusted Computing will only make the problem worse.

There is an inherent insecurity to technologies that try to own people’s computers: They allow individuals other than the computers’ legitimate owners to enforce policy on those machines. These systems invite attackers to assume the role of the third party and turn a user’s device against him.

Remember the Sony story: The most insecure feature in that DRM system was a cloaking mechanism that gave the rootkit control over whether you could see it executing or spot its files on your hard disk. By taking ownership away from you, it reduced your security.

If left to grow, these external control systems will fundamentally change your relationship with your computer. They will make your computer much less useful by letting corporations limit what you can do with it. They will make your computer much less reliable because you will no longer have control of what is running on your machine, what it does, and how the various software components interact. At the extreme, they will transform your computer into a glorified boob tube.

You can fight back against this trend by only using software that respects your boundaries. Boycott companies that don’t honestly serve their customers, that don’t disclose their alliances, that treat users like marketing assets. Use open-source software — software created and owned by users, with no hidden agendas, no secret alliances and no back-room marketing deals.

Just because computers were a liberating force in the past doesn’t mean they will be in the future. There is enormous political and economic power behind the idea that you shouldn’t truly own your computer or your software, despite having paid for it.

This essay originally appeared on Wired.com.

EDITED TO ADD (5/5): Commentary. It seems that some of my examples were not very good. I’ll come up with other ones for the Crypto-Gram version.

Posted on May 4, 2006 at 7:13 AMView Comments

The Sony Rootkit Saga Continues

I’m just not able to keep up with all the twists and turns in this story. (My previous posts are here, here, here, and here, but a way better summary of the events is on BoingBoing: here, here, and here. Actually, you should just read every post on the topic in Freedom to Tinker. This is also worth reading.)

Many readers pointed out to me that the DMCA is one of the reasons antivirus companies aren’t able to disable invasive copy-protection systems like Sony’s rootkit: it may very well be illegal for them to do so. (Adam Shostack made this point.)

Here are two posts about the rootkit before Russinovich posted about it.

And it turns out you can easily defeat the rootkit:

With a small bit of tape on the outer edge of the CD, the PC then treats the disc as an ordinary single-session music CD and the commonly used music “rip” programs continue to work as usual.

(Original here.)

The fallout from this has been simply amazing. I’ve heard from many sources that the anti-copy-protection forces in Sony and other companies have newly found power, and that copy-protection has been set back years. Let’s hope that the entertainment industry realizes that digital copy protection is a losing game here, and starts trying to make money by embracing the characteristics of digital technology instead of fighting against them. I’ve written about that here and here (both from 2001).

Even Foxtrot has a cartoon on the topic.

I think I’m done here. Others are covering this much more extensively than I am. Unless there’s a new twist that I simply have to comment on….

EDITED TO ADD (11/21): The EFF is suing Sony. (The page is a good summary of the whole saga.)

EDITED TO ADD (11/22): Here’s a great idea; Sony can use a feature of the rootkit to inform infected users that they’re infected.

As it turns out, there’s a clear solution: A self-updating messaging system already built into Sony’s XCP player. Every time a user plays a XCP-affected CD, the XCP player checks in with Sony’s server. As Russinovich explained, usually Sony’s server sends back a null response. But with small adjustments on Sony’s end — just changing the output of a single script on a Sony web server — the XCP player can automatically inform users of the software improperly installed on their hard drives, and of their resulting rights and choices.

This is so obviously the right thing to do. My guess is that it’ll never happen.

Texas is suing Sony. According to the official statement:

The suit is also the first filed under the state’s spyware law of 2005. It alleges the company surreptitiously installed the spyware on millions of compact music discs (CDs) that consumers inserted into their computers when they play the CDs, which can compromise the systems.

And here’s something I didn’t know: the rootkit consumes 1% – 2% of CPU time, whether or not you’re playing a Sony CD. You’d think there would be a “theft of services” lawsuit in there somewhere.

EDITED TO ADD (11/30): Business Week has a good article on the topic.

Posted on November 21, 2005 at 4:34 PMView Comments

Sony's DRM Rootkit: The Real Story

This is my sixth column for Wired.com:

It’s a David and Goliath story of the tech blogs defeating a mega-corporation.

On Oct. 31, Mark Russinovich broke the story in his blog: Sony BMG Music Entertainment distributed a copy-protection scheme with music CDs that secretly installed a rootkit on computers. This software tool is run without your knowledge or consent — if it’s loaded on your computer with a CD, a hacker can gain and maintain access to your system and you wouldn’t know it.

The Sony code modifies Windows so you can’t tell it’s there, a process called “cloaking” in the hacker world. It acts as spyware, surreptitiously sending information about you to Sony. And it can’t be removed; trying to get rid of it damages Windows.

This story was picked up by other blogs (including mine), followed by the computer press. Finally, the mainstream media took it up.

The outcry was so great that on Nov. 11, Sony announced it was temporarily halting production of that copy-protection scheme. That still wasn’t enough — on Nov. 14 the company announced it was pulling copy-protected CDs from store shelves and offered to replace customers’ infected CDs for free.

But that’s not the real story here.

It’s a tale of extreme hubris. Sony rolled out this incredibly invasive copy-protection scheme without ever publicly discussing its details, confident that its profits were worth modifying its customers’ computers. When its actions were first discovered, Sony offered a “fix” that didn’t remove the rootkit, just the cloaking.

Sony claimed the rootkit didn’t phone home when it did. On Nov. 4, Thomas Hesse, Sony BMG’s president of global digital business, demonstrated the company’s disdain for its customers when he said, “Most people don’t even know what a rootkit is, so why should they care about it?” in an NPR interview. Even Sony’s apology only admits that its rootkit “includes a feature that may make a user’s computer susceptible to a virus written specifically to target the software.”

However, imperious corporate behavior is not the real story either.

This drama is also about incompetence. Sony’s latest rootkit-removal tool actually leaves a gaping vulnerability. And Sony’s rootkit — designed to stop copyright infringement — itself may have infringed on copyright. As amazing as it might seem, the code seems to include an open-source MP3 encoder in violation of that library’s license agreement. But even that is not the real story.

It’s an epic of class-action lawsuits in California and elsewhere, and the focus of criminal investigations. The rootkit has even been found on computers run by the Department of Defense, to the Department of Homeland Security’s displeasure. While Sony could be prosecuted under U.S. cybercrime law, no one thinks it will be. And lawsuits are never the whole story.

This saga is full of weird twists. Some pointed out how this sort of software would degrade the reliability of Windows. Someone created malicious code that used the rootkit to hide itself. A hacker used the rootkit to avoid the spyware of a popular game. And there were even calls for a worldwide Sony boycott. After all, if you can’t trust Sony not to infect your computer when you buy its music CDs, can you trust it to sell you an uninfected computer in the first place? That’s a good question, but — again — not the real story.

It’s yet another situation where Macintosh users can watch, amused (well, mostly) from the sidelines, wondering why anyone still uses Microsoft Windows. But certainly, even that is not the real story.

The story to pay attention to here is the collusion between big media companies who try to control what we do on our computers and computer-security companies who are supposed to be protecting us.

Initial estimates are that more than half a million computers worldwide are infected with this Sony rootkit. Those are amazing infection numbers, making this one of the most serious internet epidemics of all time — on a par with worms like Blaster, Slammer, Code Red and Nimda.

What do you think of your antivirus company, the one that didn’t notice Sony’s rootkit as it infected half a million computers? And this isn’t one of those lightning-fast internet worms; this one has been spreading since mid-2004. Because it spread through infected CDs, not through internet connections, they didn’t notice? This is exactly the kind of thing we’re paying those companies to detect — especially because the rootkit was phoning home.

But much worse than not detecting it before Russinovich’s discovery was the deafening silence that followed. When a new piece of malware is found, security companies fall over themselves to clean our computers and inoculate our networks. Not in this case.

McAfee didn’t add detection code until Nov. 9, and as of Nov. 15 it doesn’t remove the rootkit, only the cloaking device. The company admits on its web page that this is a lousy compromise. “McAfee detects, removes and prevents reinstallation of XCP.” That’s the cloaking code. “Please note that removal will not impair the copyright-protection mechanisms installed from the CD. There have been reports of system crashes possibly resulting from uninstalling XCP.” Thanks for the warning.

Symantec’s response to the rootkit has, to put it kindly, evolved. At first the company didn’t consider XCP malware at all. It wasn’t until Nov. 11 that Symantec posted a tool to remove the cloaking. As of Nov. 15, it is still wishy-washy about it, explaining that “this rootkit was designed to hide a legitimate application, but it can be used to hide other objects, including malicious software.”

The only thing that makes this rootkit legitimate is that a multinational corporation put it on your computer, not a criminal organization.

You might expect Microsoft to be the first company to condemn this rootkit. After all, XCP corrupts Windows’ internals in a pretty nasty way. It’s the sort of behavior that could easily lead to system crashes — crashes that customers would blame on Microsoft. But it wasn’t until Nov. 13, when public pressure was just too great to ignore, that Microsoft announced it would update its security tools to detect and remove the cloaking portion of the rootkit.

Perhaps the only security company that deserves praise is F-Secure, the first and the loudest critic of Sony’s actions. And Sysinternals, of course, which hosts Russinovich’s blog and brought this to light.

Bad security happens. It always has and it always will. And companies do stupid things; always have and always will. But the reason we buy security products from Symantec, McAfee and others is to protect us from bad security.

I truly believed that even in the biggest and most-corporate security company there are people with hackerish instincts, people who will do the right thing and blow the whistle. That all the big security companies, with over a year’s lead time, would fail to notice or do anything about this Sony rootkit demonstrates incompetence at best, and lousy ethics at worst.

Microsoft I can understand. The company is a fan of invasive copy protection — it’s being built into the next version of Windows. Microsoft is trying to work with media companies like Sony, hoping Windows becomes the media-distribution channel of choice. And Microsoft is known for watching out for its business interests at the expense of those of its customers.

What happens when the creators of malware collude with the very companies we hire to protect us from that malware?

We users lose, that’s what happens. A dangerous and damaging rootkit gets introduced into the wild, and half a million computers get infected before anyone does anything.

Who are the security companies really working for? It’s unlikely that this Sony rootkit is the only example of a media company using this technology. Which security company has engineers looking for the others who might be doing it? And what will they do if they find one? What will they do the next time some multinational company decides that owning your computers is a good idea?

These questions are the real story, and we all deserve answers.

EDITED TO ADD (11/17): Slashdotted.

EDITED TO ADD (11/19): Details of Sony’s buyback program. And more GPL code was stolen and used in the rootkit.

Posted on November 17, 2005 at 9:08 AM

Fraudulent Stock Transactions

From a Business Week story:

During July 13-26, stocks and mutual funds had been sold, and the proceeds wired out of his account in six transactions of nearly $30,000 apiece. Murty, a 64-year-old nuclear engineering professor at North Carolina State University, could only think it was a mistake. He hadn’t sold any stock in months.

Murty dialed E*Trade the moment its call center opened at 7 a.m. A customer service rep urged him to change his password immediately. Too late. E*Trade says the computer in Murty’s Cary (N.C.) home lacked antivirus software and had been infected with code that enabled hackers to grab his user name and password.

The cybercriminals, pretending to be Murty, directed E*Trade to liquidate his holdings. Then they had the brokerage wire the proceeds to a phony account in his name at Wells Fargo Bank. The New York-based online broker says the wire instructions appeared to be legit because they contained the security code the company e-mailed to Murty to execute the transaction. But the cyberthieves had gained control of Murty’s e-mail, too.

E*Trade recovered some of the money from the Wells Fargo account and returned it to Murty. In October, the Indian-born professor reached what he calls a satisfactory settlement with the firm, which says it did nothing wrong.

That last clause is critical. E*trade insists it did nothing wrong. It executed $174,000 in fraudulent transactions, but it did nothing wrong. It sold stocks without the knowledge or consent of the owner of those stocks, but it did nothing wrong.

Now quite possibly, E*trade did nothing wrong legally. There may very well be a paragraph buried in whatever agreement this guy signed that says something like: “You agree that any trade request that comes to us with the right password, whether it came from you or not, will be processed.” But there’s the market failure. Until we fix that, these losses are an externality to E*Trade. They’ll only fix the problem up to the point where customers aren’t leaving them in droves, not to the point where the customers’ stocks are secure.

Posted on November 10, 2005 at 2:40 PMView Comments

Redefining Spyware

The problem with spyware is that it can be in the eye of the beholder. There are companies that decry the general problem, but have their own software report back to a central server.

This kind of thing can result in a conflict of interest: “Spyware is spyware only if I don’t have a corporate interest in it.” Here’s the most recent example:

Microsoft’s Windows AntiSpyware application is no longer flagging adware products from Claria Corp. as a threat to PC users.

Less than a week after published reports of acquisition talks between Microsoft Corp. and the Redwood City, Calif.-based distributor of the controversial Gator ad-serving software, security researchers have discovered that Microsoft has quietly downgraded its Claria detections.

If you’re a user of AntiSpyware, you can fix this. Claria’s spyware is now flagged as “Ignore” by default, but you can still change the action to “Quarantine” or “Remove.” I recommend “Remove.”

Edited to add: Actually, I recommend using a different anti-spyware program.

Posted on July 14, 2005 at 5:05 PMView Comments

GhostBuster

This is a really interesting technical report from Microsoft. It describes a clever prototype — called GhostBuster — they developed for detecting arbitrary persistent and stealthy software, such as rootkits, Trojans, and software keyloggers. It’s a really elegant idea, based on a simple observation: the rootkit must exist on disk to be persistent, but must lie to programs running within the infected OS in order to hide.

Here’s how it works: The user has the GhostBuster program on a CD. He sticks the CD in the drive, and from within the (possibly corrupted) OS, the checker program runs: stopping all other user programs, flushing the caches, and then doing a complete checksum of all files on the disk and a scan of any registry keys that could autostart the system, writing out the results to a file on the hard drive.

Then the user is instructed to press the reset button, the CD boots its own OS, and the scan is repeated. Any differences indicate a rootkit or other stealth software, without the need for knowing what particular rootkits are or the proper checksums for the programs installed on disk.

Simple. Clever. Elegant.

In order to fool GhostBuster, the rootkit must 1) detect that such a checking program is running and either not lie to it or change the output as it’s written to disk (in the limit this becomes the halting problem for the rootkit designer), 2) integrate into the BIOS rather than the OS (tricky, platform specific, and not always possible), or 3) give up on either being persistent or stealthy. Thus this doesn’t eliminate rootkits entirely, but is a pretty mortal blow to persistent rootkits.

Of course, the concept could be adopted for any other operating system as well.

This is a great idea, but there’s a huge problem. GhostBuster is only a research prototype, so you can’t get a copy. And, even worse, Microsoft has no plans to turn it into a commercial tool.

This is too good an idea to abandon. Microsoft, if you’re listening, you should release this tool to the world. Make it public domain. Make it open source, even. It’s a great idea, and you deserve credit for coming up with it.

Any other security companies listening? Make and sell one of these. Anyone out there looking for an open source project? Here’s a really good one.

Note: I have no idea if Microsoft patented this idea. If they did and they don’t release it, shame on them. If they didn’t, good for them.

Posted on February 15, 2005 at 8:00 AMView Comments

Safe Personal Computing

I am regularly asked what average Internet users can do to ensure their security. My first answer is usually, “Nothing–you’re screwed.”

But that’s not true, and the reality is more complicated. You’re screwed if you do nothing to protect yourself, but there are many things you can do to increase your security on the Internet.

Two years ago, I published a list of PC security recommendations. The idea was to give home users concrete actions they could take to improve security. This is an update of that list: a dozen things you can do to improve your security.

General: Turn off the computer when you’re not using it, especially if you have an “always on” Internet connection.

Laptop security: Keep your laptop with you at all times when not at home; treat it as you would a wallet or purse. Regularly purge unneeded data files from your laptop. The same goes for PDAs. People tend to store more personal data–including passwords and PINs–on PDAs than they do on laptops.

Backups: Back up regularly. Back up to disk, tape or CD-ROM. There’s a lot you can’t defend against; a recent backup will at least let you recover from an attack. Store at least one set of backups off-site (a safe-deposit box is a good place) and at least one set on-site. Remember to destroy old backups. The best way to destroy CD-Rs is to microwave them on high for five seconds. You can also break them in half or run them through better shredders.

Operating systems: If possible, don’t use Microsoft Windows. Buy a Macintosh or use Linux. If you must use Windows, set up Automatic Update so that you automatically receive security patches. And delete the files “command.com” and “cmd.exe.”

Applications: Limit the number of applications on your machine. If you don’t need it, don’t install it. If you no longer need it, uninstall it. Look into one of the free office suites as an alternative to Microsoft Office. Regularly check for updates to the applications you use and install them. Keeping your applications patched is important, but don’t lose sleep over it.

Browsing: Don’t use Microsoft Internet Explorer, period. Limit use of cookies and applets to those few sites that provide services you need. Set your browser to regularly delete cookies. Don’t assume a Web site is what it claims to be, unless you’ve typed in the URL yourself. Make sure the address bar shows the exact address, not a near-miss.

Web sites: Secure Sockets Layer (SSL) encryption does not provide any assurance that the vendor is trustworthy or that its database of customer information is secure.

Think before you do business with a Web site. Limit the financial and personal data you send to Web sites–don’t give out information unless you see a value to you. If you don’t want to give out personal information, lie. Opt out of marketing notices. If the Web site gives you the option of not storing your information for later use, take it. Use a credit card for online purchases, not a debit card.

Passwords: You can’t memorize good enough passwords any more, so don’t bother. For high-security Web sites such as banks, create long random passwords and write them down. Guard them as you would your cash: i.e., store them in your wallet, etc.

Never reuse a password for something you care about. (It’s fine to have a single password for low-security sites, such as for newspaper archive access.) Assume that all PINs can be easily broken and plan accordingly.

Never type a password you care about, such as for a bank account, into a non-SSL encrypted page. If your bank makes it possible to do that, complain to them. When they tell you that it is OK, don’t believe them; they’re wrong.

E-mail : Turn off HTML e-mail. Don’t automatically assume that any e-mail is from the “From” address.

Delete spam without reading it. Don’t open messages with file attachments, unless you know what they contain; immediately delete them. Don’t open cartoons, videos and similar “good for a laugh” files forwarded by your well-meaning friends; again, immediately delete them.

Never click links in e-mail unless you’re sure about the e-mail; copy and paste the link into your browser instead. Don’t use Outlook or Outlook Express. If you must use Microsoft Office, enable macro virus protection; in Office 2000, turn the security level to “high” and don’t trust any received files unless you have to. If you’re using Windows, turn off the “hide file extensions for known file types” option; it lets Trojan horses masquerade as other types of files. Uninstall the Windows Scripting Host if you can get along without it. If you can’t, at least change your file associations, so that script files aren’t automatically sent to the Scripting Host if you double-click them.

Antivirus and anti-spyware software : Use it–either a combined program or two separate programs. Download and install the updates, at least weekly and whenever you read about a new virus in the news. Some antivirus products automatically check for updates. Enable that feature and set it to “daily.”

Firewall : Spend $50 for a Network Address Translator firewall device; it’s likely to be good enough in default mode. On your laptop, use personal firewall software. If you can, hide your IP address. There’s no reason to allow any incoming connections from anybody.

Encryption: Install an e-mail and file encryptor (like PGP). Encrypting all your e-mail or your entire hard drive is unrealistic, but some mail is too sensitive to send in the clear. Similarly, some files on your hard drive are too sensitive to leave unencrypted.

None of the measures I’ve described are foolproof. If the secret police wants to target your data or your communications, no countermeasure on this list will stop them. But these precautions are all good network-hygiene measures, and they’ll make you a more difficult target than the computer next door. And even if you only follow a few basic measures, you’re unlikely to have any problems.

I’m stuck using Microsoft Windows and Office, but I use Opera for Web browsing and Eudora for e-mail. I use Windows Update to automatically get patches and install other patches when I hear about them. My antivirus software updates itself regularly. I keep my computer relatively clean and delete applications that I don’t need. I’m diligent about backing up my data and about storing data files that are no longer needed offline.

I’m suspicious to the point of near-paranoia about e-mail attachments and Web sites. I delete cookies and spyware. I watch URLs to make sure I know where I am, and I don’t trust unsolicited e-mails. I don’t care about low-security passwords, but try to have good passwords for accounts that involve money. I still don’t do Internet banking. I have my firewall set to deny all incoming connections. And I turn my computer off when I’m not using it.

That’s basically it. Really, it’s not that hard. The hardest part is developing an intuition about e-mail and Web sites. But that just takes experience.

This essay previously appeared on CNet

Posted on December 13, 2004 at 9:59 AMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.