Web-based attacks increased by 36 percent in 2011 compared with the previous year, Symantec, an Internet security firm, said in its "2011 Threat Landscape" report.
While we've been warned about the dangers of visiting porn sites, other types of sites are far more likely to be infected with malware, according to the report. For instance, about 20 percent of blogs host malware.
Here's the full list of Web site types, and the percentage that is infected.
Top 10 Infected Web site types
1. Blogs | 19.8%
2. Web hosting| 15.6%
3. Business and economy | 10%
4. Shopping| 7.7%
5. Education and reference | 6.9%
6. Technology, computer, Internet| 6.9%
7. Entertainment and music | 3.8%
8. Automotive | 3.8%
9. Health and medicine | 2.7%
10. Porn | 2.4%
Avoiding all of these types of sites would leave you with very little to enjoy. As for porn coming in last, Symantec says that this is because pornographic website owners already make money from the Internet and, as a result, have a vested interest in keeping their sites malware-free — it’s not good for repeat business.
Protecting yourself from drive-by malware
The most common type of attack in 2011 was the drive-by, which refers to a user visiting a site and picking up malware without knowing that an infection has occurred. Even legitimate sites can be infected with malware and can pass it on to your computer, so avoiding unknown sites is not enough.
Mac users are not immune. In addition to Mac-targeted attacks, malware makers have devised so-called cross-platform programs that work on Macs as well as Windows-based computers.
The most important thing you can do to protect yourself and your computer is to keep your antivirus software, browsers and browser add-ons up to date. Adobe Acrobat is the most commonly outdated plugin and one that's heavily exploited by malware makers, Symantec said. [ 5 Ways to Get the Most Out of Google Chrome ]
When you see a message on your screen to update an installed program, don't procrastinate — take a minute to initiate the download. Be certain it is authentic and not a bogus popup from an infected site. For instance, Adobe updates originate from the Adobe Application Updater shown in the tray located in the bottom left of your screen if you're a PC user.