Security

New York U and Google Researchers Expose Shady Business of Pay-Per-Install

• By Dian Schaffhauser
• 08/09/16

The next time you install new software, you might want to ask yourself what else is riding along. A research team at New York University and Google are reporting this week on the "shady practices" of delivering unwanted advertising and software as part of the payload of legitimate programs. The practice of commercial pay-per-install (PPI) allows companies to bundle their undesirable applications with other software that users want in return for a fee.

The research project, led by Damon McCoy, an assistant professor of computer science and engineering at New York U's Tandon School of Engineering, and Kurt Thomas, a research scientist at Google, developed an "analysis pipeline" to track the business dealings and software bundles that sustain four of the largest commercial PPI networks.

According to the researchers, unwanted ad injectors, browser settings hijackers and cleanup utilities dominate the software "families" that buy installs. The companies behind those families typically pay between a dime and $1.50 per installation, which they recoup by monetizing users without their consent or by charging exorbitant subscription fees. Worse, the research suggests that some of the affiliates distributing such software are active and willing participants in the schemes, even as they deny culpability in the installation of unwanted software. One operation identified as a player reported $460 million in revenue in 2014, generated through a combination of legitimate and unwanted software downloads.

Based on Google calculations, PPI networks push more than 60 million download attempts every week — nearly triple that of malware. While anti-virus and browser makers have developed defenses against unwanted software, the research found that PPI networks go out of their way to interfere with or evade detection, often using data gleaned during the install process and provided by the companies they're paying for the software ride-along.

How do you know when you've been a victim of PPI? The researchers describe what happens: a barrage of advertisements on the screen; flashing pop-ups warning of malware and promoting the purchase of specialized antivirus software that's often fraudulent itself. In other scenarios, the system's default browser is hijacked, and users are sent to "ad-laden pages."

The analysis of PPI appears in the paper, "Investigating Commercial Pay-Per-Install and the Distribution of Unwanted Software," which is being presented this week at the USENIX Security Symposium taking place in Austin. The paper will be openly available after the event begins.

"If you've ever downloaded a screen saver or other similar feature for your laptop, you've seen a 'terms and conditions' page pop up where you consent to the installation," New York U's McCoy explained in a statement about the research. "Buried in the text that nobody reads is information about the bundle of unwanted software programs in the package you're about to download."

What those terms and conditions do, he explained, is allow the businesses to operate legally while exploiting the trusted relationship they have with their customers. "We're hoping to expose these business practices so people are less likely to get duped into flooding their computers with programs they never wanted," McCoy said.