One of the latest types of attack methodologies involves fake virus and worm alerts, which malware authors have been refining since they first appeared in a basic form earlier in the year, Webroot said.
According to Andrew Brandt, a security researcher with the IT security vendor, for some months, the malware authors behind this fraud have been honing their skills and working to push their malicious web pages higher in the search rankings.
"Victims experience a computer that appears to be out of control, seemingly unable to do anything but download whatever application the fake alert forces upon them", said Brandt in a security blog posting.
The good news, he said, is that it is not hard to avoid these fake alert sites, but users have to be on constant alert and carefully scrutinise the results of any security scan warnings that appear on their computer screens before they click on a link.
Because of these issues, Brandt advises users to "sweep before you shop" and always scan your computer with a fully updated anti-virus and anti-spyware application before you even get to the order form on your favourite shopping site.
Internet users are also advised to look carefully at search engine results before they click.
"When in doubt, kill your browser: If you do happen to find yourself sucked into a fakealert vortex, don't click anywhere in the browser window. If you know how to use the task manager to terminate the browser application, you can do it that way", he said.
"Most users will find it easier to simply use the Alt-F4 keyboard combination. Remember, you can always go back to the page you want by restarting the browser and looking at your link history", he added.
Brandt also cautioned that malware authors and hackers are using a number of tricks to fool Google and other search engines into indexing their malicious links so they have a high relevance score, and therefore appear higher in the results than a legitimate site would.
"One of the tricks they use is to have a large number of the same key phrase interspersed in the middle of text culled from another source."
Internet users are also advised to download and use the Noscript addin to Mozilla Firefox, which stops any scripts from triggering a fake alert on a users' PC screen.