Illegal pharmaceutical supply chain outfits have become the main customers of botnet farmers. Spam-pushing botnets, such as that established by the Storm worm, are raking it in advertising dodgy drug websites, according to a study by security appliance firm IronPort.
Four out of five junk emails distributed through the Storm botnet advertise online pharmacy brands. The storm botnet has become a full-service ecommerce operation with a complex supply chain, according to IronPort's 2008 Internet Malware Trends: Storm and the Future of Social Engineering.
Spam templates, website designs, credit card processing, product shipment and even customer support are being provided by the Russian cybercrooks behind the Storm worm, according to IronPort, the spam filtering appliance division of networking giant Cisco. Malware authors recruit botnet spamming partners to promote illegal pharmacy websites, receiving commissions of as much as 40 per cent on the resulting sales.
The prescription drugs on offer were sent to people who were not examined by a doctor first, risking their health on dodgy male potency drugs and the like. IronPort made a number of purchases of spamvertised drugs. Subsequent pharmacological testing found that two-thirds of the shipments failed to include the correct dosage of an active ingredient while the rest were sugar pills (placebos).
IronPort's study fills in the detail about the relationship between botnet masters and penis pill spammers, a business it reckons generates tens of millions a year. "Our research has revealed a smoking gun that shows that Storm and other botnet spam generates commissionable orders, which are then fulfilled by the supply chains, generating revenue in excess of $150m per year." said Patrick Peterson, vice president of technology at IronPort.
The Storm worm (more accurately called a Trojan) turns over control of infected PCs to botmasters. Either social engineering trickery or web-based exploits are used to load up malware onto victimised PCs. IronPort reckons a total of 40 million computers have been infected by Storm in the period between January 2007 and February 2008. The actual number of infected machines at any one time is, of course, much lower than this.
Storm was considered to account for one in five spam messages at its peak of 1.4 million compromised PCs in July 2007, though the number infected by Storm has dropped off since then. Storm now represents only a "tiny sliver" of the spam deluge, estimated by IronPort to rack up to 186 billion messages a day. Despite this ratcheting down in activity new variants of Storm continue to appear. Other botnet agents - such as Bobax, Kraken and Srizbi - have emerged to eclipse Storm.
Better security practices would reduce the prevalence of compromised PCs, however they are attacked. Persuading the minority of misguided souls buying products through spam to stop would also undermine the business model of cybercrooks.
The report, published Wednesday, also highlights recent evolution in malware distribution and spamming tactics.
The circumvention of Captcha sign-up controls on webmail accounts, normally by semi-automated approaches, has meant that five per cent of all the spam blocked by IronPort in the first three months of 2008 was sent through Gmail, Yahoo mail and other webmail services. This compares to one per cent in the last quarter of 2007. Spammers have adopted the approach because messages sent this way are more likely to get past spam filters.
IronPort also notes that an estimated 1.3 per cent of all Google searches give malware sites as valid results, thanks to the use by miscreants of various tactics designed to inflate the ranking of hacker-controlled websites. An increase in the appearance of malicious scripts on legitimate websites is driving this trend despite the best efforts of Google and third-party security firms to contain the drive-by download menace.
The full study can be found on IronPort's website here (registration required). ®