These days, running a computer that's connected to the internet is more likely to end in tears than doing splits naked over a live lobster, especially if you've got broadband. Worms, Trojans, Viruses, script kiddies – there's loads of dangers that can inconvenience you, or even worse – wreck your computer and damage your livelihood. And it's not just protecting your computer from attacks; there's also the problem of protecting your privacy from spy-ware etc.
This free article looks at free programs which help protect against pop-up windows, spyware, tracking cookies, viruses, unauthorised connections to the web and external intrusion attempts.
What are the most vulnerable parts of your system?
The bits that interface with the net are all vulnerable, whether that's an email client, a browser and, of course, anything that you download and install. And most of the vulnerable programs are Microsoft. I'm not going to get all political here; I've no idea if Microsoft products are more secure than others, but it is a fact that targeting IE or Outlook Express is a far more attractive proposition for a virus-writer than any other email clients, simply because so many more people use them – so a virus-writer gets to cause more damage. By advocating a non-Microsoft alternative to a product, I'm not knocking Microsoft, just playing the numbers. So please don't email me and complain that I'm bashing Microsoft!
Protecting Your Web Browser.If you are only interested in designing for IE, then that's presumably the only browser you want on your system – but I bet you've got other browsers that you've installed for testing. Personally, I test in IE but surf the web more and more using Mozilla, because it's got fewer people targeting any weaknesses with exploits. There's a beta version of the newest Mozilla available, called Firefox. (Another fast text-and-tables only browser is Off By One, which leaves no cache on the hard-disc at all and is a standalone 1 meg download!).
To protect I.E., I make sure that no scripts or Active-X nasties can be dumped on me by disabling Active X downloads or setting IE to prompt me via the options in Tools > Internet options > Security > Custom Level. Because I thoroughly dislike pop-ups that I haven't asked for, I disable pop-ups using the Google toolbar. Some sites are coded to have an endless stream of pop-ups that will eventually cause your browser to crash and burn, and this can be avoided by toggling the option on the Google toolbar.
The Google toolbar blocks pop-ups.When the toolbar blocks a pop-up, the cursor changes momentarily. Toggling the button above will allow pop-ups on the site temporarily.
Internet Explorer, being a Microsoft product, also integrates with ActiveX which can allow unwanted programs to be downloaded, even if you don't request them. There's been scary stories about e-card emails which download nasties when you click to go to the site receive your card: "It includes a hidden textarea which contains ActiveX to download a.exe, and overwrite the Windows Media Player wmplayer.exe with it … ". The downloaded exe then records your keystrokes when you're using some popular legitimate internet banking software, and phones your username, password and account details back to the hacker's computer. Yikes!
My advice is to adjust the security settings to the highest possible level – or to use Mozilla for sites you don't trust totally.
Firewall.A firewall is essential. Suppose, for example, that you'd been had by the e-card stunt and a program was secretly running on your computer, collecting your credit card details and banking passwords. With a decent firewall, you'll be alerted when the malicious secret executable tries to contact with the net – and you'll get a chance to stop it!
Using your Firewall to monitor program's attempts to connect.A firewall simply sits between your applications and the net. The one I use, and thoroughly recommend, is ZoneAlarm. It's a free download (click "Download FREE ZoneAlarm") from Zonelabs. I won't go into great detail about how it works here, as there are tutorials on the site, but you 'train' it to allow programs you trust to connect to the net. For the first few days, it'll pop up and say "Do you want to allow internet Explorer to contact the net?" –you click "yes" (and optionally, "remember this answer"). Subsequently, it won't ask you for that program. So if one day, it seemingly randomly asks you if you want to allow a program you've not heard of to contact the net, even when you're not trying to connect with any legitimate application, you can just click "no". Note that this doesn't clean this program from your system – but it does stop your banking details being sent to someone in the ex-soviet union.
Of course, the golden rule of computing that garbage in = garbage out applies; if you don't think carefully about which programs you permit to connect, you could inadvertently be telling ZoneAlarm to allow some horrible Trojan to connect. Consider the connection requests carefully; explorer.exe, winword.exe, outlook.exe etc are all pretty self-explanatory, but some program names aren't easy to work out – so, if in doubt say "no" to connection but don't tell ZoneAlarm to remember the answer; if some favourite program then hangs or doesn't do what you want it to do, you can be sure that the funny-named program belongs to a legitimate application, restart it and then say "yes" to ZoneAlarm and tell it to remember this in the future.
Using a Firewall to monitor outside attempts to break in. The firewall also monitors intrusion attempts. When you're connected to the net, you're not just connected to the web. Malicious people and programs (like many of the worms that were spreading a few months ago) continually poll for machines connected to the web which aren't protected, and can introduce all kinds of nasties. ZoneAlarm will pop up an informational message telling you every time someone attempts to intrude through your connection – although fortunately, it is for information only; it's already denied access. (You can turn those messages off if they're interrupting you too frequently).
ZoneAlarm shows you that it successfully blocked an intrusion attempt
At the height of the blaster worm, I left my broadband connection on for an hour at lunchtime with no open browsers on my machine and when I came back from my lunch, ZoneAlarm reported 293 attempts to hack into my system! If only one of those were successful, I could've found myself in possession of a machine which was performing a denial of service attack on someone else, sending out spam, or hosting pornography.
It's best to have a firewall whenever you connect to the web; it's essential with broadband, where people tend to have an open connection for as long as the machine is on – and, of course, malicious code can be downloaded very fast without the machine noticeably slowing down and arousing your suspicions.
Spyware removal.What is "Spyware"?Spyware is a generic term for programs which you've chosen to install but which have an unwanted facility to "phone home" with information about what you use the program for. There's various sub-types; hijackers change your default search page-not-found page, Trojans allow other programs in that can do malign things like use your computer as a spam relay, and the infamous dialers hijack your modem so that looking at certain sites (often porn or casino sites) goes through their own premium rate phone lines. Even nastier than this are dialers that use a premium phone line (sometimes up to $5/ minute) for *all* web access! What these programs all have in common is that you choose to install them.
The least malignant of these is often known by the loaded term "adware". They're not always bad; for example, the Google toolbar can contact Google and tell it where you've been surfing – not identifying you by name, but giving aggregate data to help them improve their ranking software. Many users don't mind this. With other applications, however, the fact that the software will phone home is buried deep within the terms and conditions and is actually the only reason for the manufacturers to make the software, as they can sell the information they collect to marketing firms, or else tailor search results to go to sites that they control and make percentage on.
The list of spyware applications is enormous; most "fun" apps that plug into your email client or browser to give you animated gifs, smileys, groovy cursors are actually phoning home about where you visit when you surf the web. For example, the Hotbar software's terms and conditions states:
"HOTBAR COLLECTS AND STORES INFORMATION ABOUT THE WEB PAGES YOU VIEW AND THE DATA YOU ENTER IN SEARCH ENGINE SEARCH FIELDS WHILE USING THE SOFTWARE. HOTBAR USES THIS INFORMATION TO DETERMINE WHICH ADS AND BUTTONS TO DISPLAY ON YOUR HOTBAR TOOLBARS AND WHICH ADS TO SHOW YOUR BROWSER." - http://www.hotbar.com/
Other such applications are found in the Kazaa peer-to-peer file "sharing" client, (but not Kazaa Lite). The applications mentioned above (and many other adware applications) are perfectly legal; you choose to install them, you accept the terms and conditions, so it's all above board. Some are less benign; some hijack your browser's "web site cannot connect" message or search engine; these are always confined to Internet Explorer, as that's the dominant browser.
Getting rid of installed Spyware is not always easy. My two favourite programs are AdAware from LavaSoft and Spybot search and destroy (there's more, but I haven't tried them). Each of my recommended applications find spyware that the other doesn't (I guess because of their update cycles). Both of these free programs, when run, scan through your system and registry looking for spyware, dialers etc and report at the end, allowing you to delete them, much like commercial anti-virus programs. In addition to spyware, they will detect marketing cookies (more of these later).
NB: AdAware makes a noise when it finishes its scan. It makes me jump out of my skin every time, if I forget to turn the computer sound down!
Virus Scanning.No matter how hard you try, viruses can sneak into your system. Commercial virus-scanners like Norton Anti-Virus will scan every email coming in, going out, and also do a full system search on command or at scheduled intervals, and delete viruses. Personally, I recommend paying the money for a commercial app; it might cost a few dollars, but your professional reputation is worth a lot – and is easily damaged if you start inadvertently sending viruses to clients, and the hours spent cleaning up a compromised system will not be billable to any client!
A freeware anti-virus program that I haven't tried but have heard good reports of is AVG anti-virus which is free to individual home users, with no technical support and without scheduling of tasks, e.g. you have to remember to set it to scan manually. It includes:
AVG Resident Protection
AVG e-mail Scanner
AVG On-Demand Scanner
Basic Scheduled Tests
Free Virus Database Updates
Automatic Update feature
Easy-To-Use Interface
Automatic Healing of infected files
AVG Virus Vault for safe handling of infected files
Any virus scanner is only as good as the virus definitions. Especially if you're on dial-up, you must download the latest definitions; otherwise it won't catch any nasties newer than the last definition file you downloaded!
Privacy Protection.Cookies are a very useful tool in the web developer's trade. At DMXzone, we use them in order to recognise you when you login and to store information on our server about which extensions and premium tutorials you own in order than you can download updates or code whenever you want. Amazon uses cookies to recognise you for their incredibly powerful personalisation suite. (A great article on how to set cookies can be found here).
Some cookies can be used by marketers for example – these are called "tracking cookies" or "data miners". Ah! You might say, cookies can only be read by the domain that served them, so they can't track me across the web. Yes and no, I reply. Many sites serve adverts from 3rd party sites, which set a cookie (fastclick.com and doubleclick.com are common, and there's others for adult sites). When you go to another site, that uses the same advertising server, it can read the cookies set before and build up a profile of where you go. Doubleclick advertisers can figure out who you are as long as you have ever bought anything online or filled out a form from one of their client sites, which is potentially a privacy invasion.
So for example, you go to www.widget.com which serves an ad from www.snoop-ad.com which sets a cookie. When you later go to www.thingie.com, if it also serves an ad from www.snoop-ad.com, the advertising company knows that you went to both sites, and could report that back to the site owners. Maybe you don't mind; maybe, like me, you don't want people tracking your surfing and purchases.
You can opt-out of doubleclick's cookies here, or spyware scanners will pick them up. Alternatively, just be sure periodically to clear the cookies stored in your browser.
Summary.It's a hard business keeping your computer safe, secure and happy on the wild west of the web. But you can increase your chances of being nasties-free, without harming your wallet, using the programs I've detailed above. Bear in mind, these are free programs and may not continue to be updated and developed by their creators – or may indeed cease to be free. Good luck, and stay computer-healthy!
