Malware is being shape-shifted or downloaded from multiple sources.

According to Viorel Canj, head of BitDefender anti-virus lab, there is a false sense of both insecurity and security when it comes to web-based malware as it can often be well-disguised or repackaged, only executing once it is downloaded.

Stefan said malware is being re-packaged with layers and, because it is hosted for download, the most important vector is the URL. He said the main focus for anti-virus software should be to detect that.

He said: “Now you will get repackaged malware with a different packer. It does not need a rogue effort from a writer, you just use code that is downloaded; and you are not sure what you have downloaded.

“There are technologies that defend against it, but the end-user will see differences from what is originally created and it can be a botnet, a keylogger or something different.

“These are the challenges we are trying to overcome. The main challenge is in educating the user, and the industry is not successful at that.”

Stefan added that users are "never completely safe" due to vulnerabilities in security software and operating systems, and the industry cannot guarantee that users will not get infected.