Researchers at Cisco's anti-spam tools maker IronPort have uncovered the shadowy links between spammers and illegal pharmaceutical businesses which are generating annual revenues in excess of £77m ($150m).

The IronPort researchers demonstrated that more than 80 per cent of spam generated by the infamous Storm botnet was used to advertise online pharmacy brands. This was then integrated with a pharmacy supply chain operated by Russian mobsters to generate more than £77m a year.

While the link between spam and the supply of dubious pharmaceuticals may seem obvious, the sophistication of the operation was breathtaking, said IronPort.

"Our previous research revealed an extremely sophisticated supply chain behind the illegal pharmacy products shipped after orders were placed on botnet-spammed Canadian pharmacy websites. But the relationship between the technology-focused botnet masters and the global supply chain organizations was murky until now," said Patrick Peterson, vice president of technology at IronPort in a statement.

Storm-like botnets are being created using a variety of social engineering and hacking techniques, resulting in tens of millions of machines being infected. These are then used to flood the internet with spam. Those foolish enough to respond to the spam are then served by criminal gangs able to offer order fulfilment, credit card processing and customer support services.

IronPort also tested the quality of drugs sold using the nefarious methods: two-thirds actually contained the active ingredient they claimed, but overwhelmingly at the wrong dosage; the rest were just placebos.