The FDA, which is responsible for ensuring the safety of, amongst other things, drugs, food products, dietary supplements and medical supplies in the United States, issued 22 warning letters to operators of the websites in a campaign which it dubbed the International Internet Week of Action. Notices were also sent to service providers and domain name registrars, advising them that their customers were illegally selling pharmaceutical products.

In many cases, the sites attempt to pass themselves off as reputable pharmaceutical companies, although many sites have been linked to malicious activity, such as the distribution of spam or the distribution of various forms of malware. In particular, websites purporting to sell Viagra and particular forms of steroid have become synonymous with spam activity.

But health officials warn that the risks of using such sites are greater than computer security risks, with drugs being sold by unauthorised websites frequently counterfeits which may not be safe for human consumption.

“Many US consumers are being misled in the hopes of saving money by purchasing prescription drugs over the internet from illegal pharmacies,” FDA Commissioner Margaret A. Hamburg said. “Taking these drugs can pose a danger to consumers.”

The problem of online drug stores was highlighted by a report in August of this year, which revealed that 89.7% of online pharmacy advertisements shown on the Microsoft-powered Bing! search engine were for websites that were unlawful.

Prison sentences of five years or more could be introduced for cyber crimes, up from the current penalty of one-three years, in an attempt to reduce online security threats and the associated cost to the European economy of issues such as computer viruses, spyware and online fraud.

The proposals come after recent mass-scale attacks on computer systems in Lithuania and Estonia and would bring the 27 EC states into line with countries such as the UK, France and Germany who already have tougher sentences for cyber criminals.

“We need new legislation to fight cyber attacks. Large-scale attacks are on the rise but the penalties . . . are not severe enough to dissuade criminals,” Radomir Jansky, a senior cybercrime official within the Commission’s Directorate-General for Justice, Freedom and Security, told the Financial Times.

“The cost for businesses, law enforcement and state authorities is on the rise, and we need to recognise that,” he added.

Mr Jansky was speaking at a meeting of the Messaging Anti-Abuse Working Group in Amsterdam, a meeting of internet service providers and industry professionals to discuss issues such as spam, botnets (networks of hacked computers) and email marketing.

The move is part of a wider strategy to promote IT security and harmonise cyber crime enforcement across the European Economic Area (EEA). Other initiatives include a Europe-wide reporting system which allows countries to quickly communicate details of an attack to fellow member states.

The EU-backed Insafe scheme has also taken steps to promote IT security, the benefits of antivirus software and computer best practice to European citizens with initiatives such as Safer Internet Day.

Last month, US President Barack Obama also highlighted the issues of IT crime, claiming that losses from cybercrime – including industrial espionage and identity theft – totalled a staggering $1,000bn (€706bn, £617bn).

A recent survey in Australia put the cost of online threats to Australian business at AU$649m (US$514m) per year.

Following the outbreak of swine flu in Mexico and numerous subsequent cases worldwide, a number of websites and email campaigns have emerged which purport to provide cures and treatment for the virus.

Those sites, it is claimed, are providing bogus treatments whilst computer security experts believe that many others may be being used as a means of distributing malicious software.

AFP reported than an alert posted late Thursday at the US Food and Drug Administration warned that scammers have launched websites promoting bogus products “that claim to prevent, treat, or cure” the H1N1 flu virus.

The FDA said it is “informing offending websites that they must take prompt action to correct and/or remove promotions of these fraudulent products or face immediate enforcement action.”

Users are being urged to look out for emails with terms such as “Swine Flu Outbreak!” and “Madonna Catches Swine Flu!” in their subject line – terms which have been heavily featured in the global media.

Japan’s National Institute of Infectious Diseases issued a warning on Thursday that a suspicious Japanese-language email message with an attached file called “information on swine flu” had been circulating in cyberspace.