Once upon a time simple advice could be followed to avoid computer viruses such as "Don't open e-mail attachments from strangers" or "Be careful what you download from the Internet."  Well, things are more complicated now: you can get virus and other malware infections on the Internet by simply navigating to websites, even those ranking high in search results from trusted sources like the Google search engine.  For several recent news  topics such as the Olympic games, a large earthquake in Chile, and Apple's iPad product announcements, many high ranking Google search results directed users to websites which contained malicious code that performed  "drive-by-download" attacks that infected users' computers with malware.

To perform drive-by-download attacks cybercriminals inject malicious code into popular, well-known websites, or alternatively monitor popular search topics (as can be found via the Google Trends website) and create their own websites which contain malware.  They use search engine optimization techniques to rank these websites high in Google search results for relevant keywords (often called "SEO poisoning" or "search poisoning" ).  When users click on the "poisoned" search results for the topics, the malware is automatically downloaded from the website to the users' computers via Javascript or other types of code.

Similarly, malware authors keep track of popular/"trending" topics in Twitter and create Twitter posts on these topics with links to sites that serve malware.  The popularity of shortened links, which hide the actual web address of linked websites on Twitter, is used to advantage by cybercriminals as users cannot easily tell if they link is to a suspicious web address.  A shortened link previewing function in the Twitter client Tweet Deck, as well as other shortened URL preview services, can help you determine the actual web addresses to which shortened URLs lead .

Important steps to protect your computer from drive-by-downloads include using antivirus software, firewalls, and  keeping your computer software up to date.  If you use the Firefox browser, a free extension/plug-in called  NoScript can also help avoid drive-by-downloads.  NoScript by default disables code such as Javascript from working on websites, which can prevent malicious scripts from installing malware on your computer.  When scripts are essential for the operation of certain sites, you have the option of allowing certain or all scripts to run on those sites, and can choose to allow them temporarily or to add them to a whitelist, which enables the scripts each time you visit the site. 

Products such as Sandboxie and Zone Alarm ForceField are designed to prevent drive-by-downloads and other Internet-borne malware attacks from affecting your computer by using "sandboxing" technology to try to isolate your web browser's activities from your computer's other activities.

LinkScanner and McAfee SiteAdvisor, and Web of Trust are browser extensions/plug-ins for browsers including Firefox and Internet Explorer that integrate with search results in your web browser to alert you to websites that potentially contain malicious code.  The warnings may not always be up-to-date or reliable, and any use should be in conjunction with other protection such as antivirus software, extensions/plugins such as NoScript, and/or sandboxing technology.  Internet Explorer 8 also has a "Smart Screen" feature which can be turned on to give similar warnings about website safety.

Other resources:

ABA Family Law eNewsletter

Avoid Loss of Law Firm Data and Business Downtime by Keeping Software Updated

 

Network World

Scammers abuse Google Trends to poison search results

 

MSNBC

Virus experts warn of 'Google poisoning'

 

Sophos

Olympic SEO Poisoning

 

McAfee Labs 

Chilean Earthquake Spawns Malware

 

Symantec

iPad SEO Poisoning Leads To Rogue Security Software

 

ZDNet

Cybercriminals hijack Twitter trending topics to serve malware