The UK has been named the cybercrime capital of Europe for targeted attacks as hackers become ever more adept at leveraging firm’s computers against them, according to the security vendor Symantec.

A report from the firm found that targeted attacks, which are deliberately aimed at certain firms, were mostly falling on small and medium businesses, which also had the effect of putting their business partners at risk.

Kevin Haley, director at Symantec Security Response, said: "Attackers don’t need to break down the door to a company’s network when the keys are readily available.

"We’re seeing attackers trick companies into infecting themselves by trojanising software updates to common programs and patiently waiting for their targets to download them — giving attackers unfettered access to the corporate network."

Attackers were also narrowing their scope in other ways by reducing emails sent by 14% and reducing the number of recipients by a fifth.

However the number of new malware threats uncovered by the report had risen by a quarter, with almost a million being released per day.

"Cybercriminals are inherently lazy; they prefer automated tools and the help of unwitting consumers to do their dirty work," Haley said.

"Last year, 70% of social media scams were shared manually, as attackers took advantage of people’s willingness to trust content shared by their friends."