Internet Safety: How do I keep my computer safe on the internet?

Use a Firewall

A firewall is a piece of software or hardware that sits between your computer and the network and only allows certain types of data to cross. For example, a firewall may allow checking email and browsing the web, but disallow things like Windows file sharing.

If you're using a dial-up internet connection, a firewall may not be as important, although it doesn't hurt to have one. A software firewall may be your only option, though.

• What's a firewall, and how do I set one up?

• Do I need a firewall, and if so, what kind?

• So do I need SP2's Windows Firewall or not?

• Is an outbound firewall needed?

Scan for Viruses

Sometimes, typically via email or other means, viruses are able to cross the firewall and end up on your computer anyway.

A virus scanner will locate and remove them from your hard disk. A real-time virus scanner will notice them as they arrive, even before they hit the disk, but at the cost of slowing down your machine a little.

Important: Because new viruses are arriving every day, it's important to keep your virus definitions up-to-date. Be sure to enable the scanning software's automatic-update feature and have it do so every day.

• What Security Software do you recommend?

• Viruses: How do I keep myself safe from Viruses?

• I run Anti-Virus software, why do I still sometimes get infected?

• When do I actually need to run a virus scan?

• How do I run an anti-virus scan if I can't boot?

Scan for Spyware

Spyware is similar to viruses in that they arrive unexpected and unannounced and proceed to do something undesired. Spyware can be relatively benign from a pure safety perspective, as it might "only" spy on you. But that's enough. It can violate your privacy by tracking the web sites that you visit, add "features" to your system that you didn't ask for, or record your keystrokes and steal your account login information for any online services that you might use.

Some of the worst offenders are spyware that hijack normal functions for themselves. For example, some like to redirect your web searches to other sites to try and sell you something. Of course, some spyware is so poorly written that it might as well be a virus, given how unstable it can make your system. The good news is that, like virus scanners, there are spyware scanners that will locate and remove the offending software.

• What Security Software do you recommend?

• Spyware: How do I remove and avoid spyware?

• Is running two anti-spyware programs better than one?

• So just how sneaky can spyware be?

• Will using an on screen keyboard stop keyboard loggers and hackers?

Stay Up-To-Date

I'd wager that over 90% of virus infections don't have to happen. Software vulnerabilities that the viruses exploit usually already have patches available by the time the virus reaches a computer.

The problem? The user simply failed to install the latest patches and updates that would have prevented the infection in the first place.

The solution is simple: enable automatic updates in both Windows and applications, and visit Windows Update periodically.

• How do I make sure that Windows is up-to-date?

• I got burned by Windows Update, should I just avoid it?

• How do I know if these update notifications are legitimate?

Educate Yourself

To be blunt, all of the protection in the world won't save you from yourself.

Don't open attachments that you aren't positive are OK. Don't fall for phishing scams. Be skeptical.

Don't click on links in email that you aren't positive are safe.

Don't install "free" software without checking it out first - many "free" packages are so because they come loaded with spyware, adware, and worse.

When visiting a web site, did you get a pop-up asking if it's OK to install some software that you're not sure of because you've never heard of it? Don't say "OK".

Not sure about some security warning that you've been given? Don't ignore it.

Choose strong passwords and don't share them with others.

• What's a good password?

• Passwords and Authentication

• Phishing? What's Phishing?

• Why won't this "Your Computer Is Infected" warning go away?

Secure Your Mobile Connection

If you're traveling and using internet hot spots, free WiFi, or internet cafes, you must take extra precautions.

Make sure that your web email access is via secure (https) connections or that your regular mail is over an encrypted connection as well. Don't let people "shoulder surf" and steal your password by watching you type it in a public place. Make sure that your home WiFi has WPA security enabled, if anyone can walk within range.

• How do I use an open WiFi hotspot safely?

• How can I keep my email safe from sniffing?

• Can hackers see data going to and from my computer?

Don't forget the physical

An old computer adage is that "if it's not physically secure, it's not secure."

All of the precautions that I've listed above are pointless if other people can get at your computer. They may not follow the safety rules that I've laid out. A thief can easily get at all of the unencrypted data on your computer if they can physically get to it.

The common scenario is a laptop being lost or stolen during travel, but I've gotten reports of people who've been burned because a family member or roommate accessed their computer without their knowledge.

• How can I keep data on my laptop secure?, What backup program should I use?

• My computer was stolen. It's password protected, what files can the thieves see?

• I've lost the password to my Windows Administrator account, how do I get it back? It turns out that resetting an Windows account password is frighteningly easy, as long as you have access to the machine.

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I know it all might seem overwhelming, but it's not nearly as overwhelming as an actual security problem if and when it happens to you. While we might want it to be otherwise, the practical reality of the internet and computing today is that we each must take responsibility for our own security online.

(This is an update to an article originally published June 19th, 2005.)