Consumers have lost almost $8.5 billion over the last two years to viruses, spyware, and phishing attacks. But computer security problems have been good for the computer business -- consumers replaced some 2.1 million computers because of malware infections.

Consumer Reports published these findings in its September issue as part of its annual State of the Net survey. The data is based on a survey of 2,071 online households conducted by the Consumer Reports National Research Center.

Among other notable data points: Consumers have a 1 in 6 chance of being victimized by cybercrime, down from a 1 in 4 chance in 2007; 19% of respondents said they didn't have antivirus software on their computers; and 75% of respondents said they didn't have an anti-phishing toolbar.

Consumer Reports also lists what it considers to be the seven most common online blunders. These include failing to keep antivirus software up to date; clicking on e-mail links to access financial Web sites; using a single password for all online accounts; downloading free software; assuming that Macs are safer than Windows PCs; clicking on "scareware" pop-up ads that claim your computer is at risk; and shopping online without taking extra precautions.

Consumer Reports' issue with Macs is that Mac users fall for phishing scams at about the same rate as PC users, yet fewer of them use anti-phishing toolbars than PC users. Because Apple's Safari Web browser does not have built-in phishing protection, Consumer Reports recommends using the most recent versions of Firefox or Opera instead of Safari, as well as trying a free anti-phishing toolbar like McAfee Site Advisor or FirePhish.

However, falling for a phishing scam could be characterized as more of an issue of user gullibility than of platform or application security. And despite singling out faith in the protective power of Macs as one of its seven online blunders, Consumer Reports noted, "As in our past surveys, very few Macintosh users reported so much as a single virus or spyware infection."

The magazine also has some kind words for Microsoft's Windows Vista operating system. It says that Windows Vista users were "significantly less likely to report a spyware infection and less likely to report a virus infection than other Windows users."