I’ve been online, in one form or another, since Compuserve and Pipeline and I’ve never ever had a problem with malware. I have a firewall and my e-mail scans for problems but I don’t use anti-virus software. My only guiding rule is that I thorougly check out the source of whatever it is I’m downloading so torrents, for example, are out.
How common is my experience? This applies to personal computers as opposed to work computers (which have a different vulnerabilities).
Are you sure your computer is clean? Have you tried running a scan to verify that? If we expand your definition of viruses to include spyware/malware I would say your experience is probably very rare, assuming of course you’re a Windows user.
I do use Windows. As for whether or not I’m sure, I can’t say so definitely, there’s always something I could have missed but I do check for viruses/spyware/malware fairly often and nothing has ever come up.
I should clarify that when I say I don’t use anti-virus software I mean I don’t have anything running in the background (Norton, McAfee etc.). I do, however, do fairly regular scans with lavasoft or other programs.
A lot of viruses and malware don’t have visible symptoms. For example, some viruses and such are set up as members of a denial of service attack, where basically every infected computer sends a message periodically to the victim site. Your computer won’t really notice the few extra network packets that it is sending out, but when a few million computers are infected the victim site is so overwhelmed with messages that it can’t function (that’s why it is called a denial of service attack).
So while it could be that your computer is infected and you don’t know it, there is also a fair chance that it’s not infected. I’ve had very few virus problems over the years, though I do have a virus scanner so I have at least been aware of them when they’ve happened. Being careful about what sites you access and only downloading from certain trusted sites does go a long way to prevent viruses and malware.
There are some good anti-virus programs out there that are free (I personally recommend Avast), so there’s no really good reason not to run an anti-virus these days.
Stuff like adaware from lavasoft won’t tell you if you have a virus, by the way. Those types of programs only scan for certain types of malware.
Based on your descriptions so far I’d only give you about a 50/50 chance of really having a clean system. I wouldn’t be terribly surprised if you did, but I wouldn’t be terribly surprised if you didn’t either.
It’s not that uncommon for people who are computer-literate and aware of what they’re doing. It’s very uncommon for the population of computer users at large. Like many geeks, I can always make a few bucks by cleaning viruses and malware from the computers of friends, coworkers, etc. There’s a never-ending supply of people whose computers are completely overrun with the stuff.
I only browse the Internet using Firefox, with the NoScript addon. That cuts down my risk of infection enormously.
I could have said I was you until shortly before Thanksgiving, when a malicious ad on a usually-trustworthy webpage put a keylogger on my machine (fortunately for me, the only casualty was portions of my EVE Online bank account).
As I said previously, I use other programs besides lavasoft. In particular, I use Kaspersky’s virus scan.
Do you like Avast better?
I wouldn’t be terribly surprised either way, myself. I just find it odd how often people seem to have their computers hijacked to the point that a complete re-install is the only way to get the thing operable again.
I won’t pay for an anti-virus program because I have problems so seldom. The last time I got a problem it was my own fault. I do have AVG and spybot installed, just in case though. I’m sure a large part of it is that I use webmail and it’s all scanned on the server. I also scan any download that I don’t trust. I do some risky things (torrents and such), but I’m selective and the things I download aren’t popular enough to be worth putting a virus in.
There’s plenty of good free antivirus and antivirus tools available, so there’s no reason to pay for it. But it’s worth having; I’ve had some warnings about things – websites or e-mails – that could have been trouble. Overall, I figure I’m pretty clean (and I know how to clean most malware in case of trouble), but I wouldn’t think of going on the net without some antivirus. When you need it, you neeeeeeed it.
Depending on what else you’re doing with the computer, you may simply have been lucky, or you might even be infected and not know it.
Apart from being infected from programs that you explicitly install (which, if you’re careful and reasonably savvy, is fairly safe), there are other risks, such as:
Using USB removable storage to move files between computers (things like conficker will silently infect the USB stick when it is plugged into a compromised machine and silently infect any other machine that stick is subsequently plugged into.
Vulnerabilities in any of the software you’re running - especially if that software opens documents that are out there on the net - web browsers, chat clients, remote access tools, FTP clients, etc - may all be vulnerable to attack - and again, it can happen without you doing anything that anyone could identify in advance as risky.