Malware ecosystem thrives thanks to pay-per-install fees

Booming economy

A report published Wednesday exposes a growing ecosystem that combines the talents of software developers, web marketers, and ordinary grunts to infect millions of end users' machines.

Similar to the Amway, Shaklee, and other direct marketing businesses of yesteryear, the PPI, or pay-per-install, model relies on average joes as its foot soldiers. Once they sign on, they can avail themselves of a wide array of services offered by other businesses and earn a small fee for each computer they infect.

Once the business model of Adware purveyors such as 180solutions (which later changed its name to Zango), the affiliate system has been fully embraced by groups pushing some of the world's nastiest trojans, according to Kevin Stevens, a security researcher at SecureWorks' Counter Threat Unit.

"The PPI business has seen significant and malicious changes over the years," he wrote in the report. "This economy is so widespread that there is even a side business selling programs to make it more difficult for computer users to detect that they are installing something malicious."

The report coincides with the release of a separate study from security firm Finjan, which discovered a piece of malware called the URLZone trojan that's so advanced it rewrites online bank statements in real time to prevent victims from learning their accounts have been wiped out. During 22 days in August, the malware succeeded in stealing €300,000 from some 6,400 German bank accounts.

At the heart of the ecosystem making much of this possible is a series of sites that claim to pay as much as $140 for every 1,000 PCs a hired gun infects. They offer enterprising criminals everything they need to break into the world of malicious software installation.

A site called InstallsCash, for instance, supplied affiliates with a trojan called Piptea, which acts as a backdoor on infected PCs so that botmasters can regularly infuse it with updates and new offerings. The Piptea authors, in turn, receive fees from other malware vendors such as those behind Virut, a nasty trojan that plants yet another backdoor on victims' machines. (InstallsCash, which recently went dormant, appears to have changed its name to Earning4u.)

In addition to supplying the malware, the sites also sell software and services that help the affiliates. The PXCrypter, for example, costs $75 and cloaks malicious downloads so they're not detected by anti-virus software (additional "stubs," which must be updated regularly, sell for $25). A trojan download manager called SDdownloader, short for Silent Downloader, usually sells for $300 but is currently on sale for $225.

Other services offered include black hat search engine optimization to ensure malicious webpages are featured prominently in results by Google ad other search engines. Seedboxes for uploading and downloading digital files and propagating them onto BitTorrent and other peer-to-peer services is also available.

The glue holding much of this together is a series of forums where participants get together to share tips, ask questions, and advertise their offerings. Sites such as www.pay-per-install.org also list prices offered by various affiliate programs. Fees vary widely. Affiliates earn $6 per 1,000 infected computers located in Asia, $30 when they're in France, $60 in Italy, $110 in the UK and $140 in the US.

Interestingly, Earning4u.com refuses to pay for installation on PCs located in Russia or other members of the former Soviet Republic. ®

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