A report has said that 70 per cent of the top 100 most visited sites around the world either hosts malicious content or contains masked links to malicious websites.
According to the latest Websense State of Security white paper, this represented a 16 per cent increase over the last six months.
Carl Leonard, Websense's threat research manager for EMEA, said the affected sites were those that most people on the internet visit, including search engines and sites which allowed user generated content like Google, Facebook, Windows Live, MySpace and Twitter.
Leonard added that this was of major importance to businesses as they were increasingly using web 2.0 tools, while sites like LinkedIn, Twitter and to a lesser degree Facebook had business uses.
He said: "Sites like YouTube are being increasingly embraced, such as when uploading marketing and promotional videos."
Leonard explained that the 16 per cent increase in targeting the top 100 sites was due to cybercriminals aiming to infect as many sites as possible to broaden their reach. They were increasing the amount of data stealing code so that they could access and trade confidential information.
"The way they are doing this is generally though automated means. Because the top 100 are the most frequently viewed sites, there is a well-established user base there," he said.
He added: "They can affect fewer sites in the top 100 to get as much exposure from more of the less popular websites."
In the last six months, Websense also saw one in five malicious applications linked back to the UK. In September, 60 per cent global malware connected back directly to the UK.
Leonard said: "Traditionally users considered that the sorts of sites that these applications communicated back to were from Russia and China. The number of other countries these malicious applications were linking to is increasing."
Websense suspected that instead of putting their eggs in one basket, malware authors were distributing their code and hosting in different countries, dodging law enforcement as well traditional security solutions.
