COLUMBIA, S.C. (USA TODAY) -- The days of computer users claiming virus problems were strictly a PC-only problem are gone.
More and more OS X users are falling victim to various adware and spyware infections, though still less so than Microsoft Windows-based computers.
Most adware and spyware infections happen when Mac or PC users install some computer programs developed by third-party programmers, called "freeware," and some examples are video downloaders, file converters or PDF-file generators.
In one case noted by makers of free adware removal software Bitdefender, an adware application known as "Genieo" becomes bundled with very popular freeware applications users install on their Mac- and PC-based computers.
After installation on a Mac, Genieo hijacks the web browser's start page and ties it to their own search engine. After users search for something, Genieo then will present "contextual advertising" as search results, also known as affiliate links (read: search results placement paid to Genieo from advertisers) within the displayed search results.
Granted every time a computer user conducts a search on Google, a similar contextual advertising search result is presented, though Google clearly marks those as ads. On a Mac or Windows computer infected with the Genieo adware, information is sent back to Genieo's servers for indexing after every search.
On Windows computers, the adware deploys a rootkit component that acts like a watchdog: It makes sure the browser plugin starts alongside a search engine so that even if the user attempts to uninstall the plugin, it is automatically restored. Even if the user successfully rids the Windows-based system of this adware application, the modified search settings will not be restored until the user manually restores them to the default values.
"Adware has become a major issue on all operating systems, regardless of their vendor, mostly because potentially unwanted applications are frequently bundled with very popular freeware programs," said Catalin Cosoi, chief security strategist at Bitdefender.
The programmers at Bitdefender have a free Mac OS X adware removal tool that will detect and remove all elements of the Genieo adware and restore the web browser settings. They intend to expand the scope of this adware removal tool, with additional functions and features, in the near future.
The free adware removal tool for Mac is available on their website at http://www.bitdefender.com/solutions/adware-removal-tool.html, along with a full line of free virus, adware, and spyware scanners for desktop and mobile devices, available at http://www.bitdefender.com/solutions.