Spammers have set a new benchmark for mockery, hijacking PCs inside drug giant Pfizer to send out adverts for the company’s most famous product, Viagra, it has been claimed.

According to US botnet tracking company Support Intelligence, a total of 138 IP addresses inside the company’s various networks have had to be blacklisted after being found to be relaying spam. In an interview with Wired, the company reports that it has kept 600 examples of spam emails said to have come from Pfizer-owned computers in the last six months.

Most incredible of all, however, is the fact that some of these emails appear to have been designed to sell the company’s own erectile dysfunction product, Viagra, as well as equivalents from rivals such as Eli Lily.

None of the recipients of these emails would have been aware that Pfizer was being used to send the spam, however, as the spoof return address gives the impression that they are from Google Gmail accounts.

Other leading companies, including Toshiba and Bank of America have also been affected by the botnet/zombie phenomenon. Oddly, Support Intelligence had informed Pfizer of the particular issue on its network, but that hadn’t stopped the activity, the company said.

The company appears to take some pleasure in pointing out just how many large organisations are affected by the botnet scourge, even, in some cases, as they report on it. In a June blog, the author taunts the BBC for having problems on its own network, but ends up grudgingly commending the organisation for solving the issue in advance of being notified.