Multilayered protection needed

A memory stick carried in by a worker tends to bypass computer security systems designed to guard against hackers breaking in from outside the walls of a business, according to Williams.

Businesses should establish security protocols for removable media drives, and have new arrivals automatically scanned for malware, Microsoft recommends.

"The criminals out there are becoming more overt, more malicious and more direct in their attacks," Williams said.

"That emphasises the need for multilayer protections. It is great we have anti-virus software to remove the threats, but clearly it is better to prevent the threat from getting in."

Cyber criminals are moving with increasing speed when it comes to reverse engineering patches released to fix vulnerabilities in software programs or operating systems, according to Microsoft.

Hackers dissect patches to identify weakness being repaired, then craft malicious code to take advantage of flaws in machines with software that isn't kept up-to-date.

"A patch is released and that is what starts these days of risk" Williams said.

"There is a window of vulnerability, so we need to close that window more quickly" he said. "Making sure you are up-to-date on security updates is one strong method of protecting yourself against attack."

Microsoft's security report is based on data from "billions of scans a day" in more than 200 regions of the world.