Original URL: http://www.theregister.co.uk/2005/11/03/secfocus_drm/

Hidden DRM code's legitimacy questioned

When bad software happens to good people

By SecurityFocus

Posted in Security, 3rd November 2005 11:07 GMT

The latest headache for security professionals has become a secret weapon in the battle between copyright owners and their customers.

This week, two research groups independently and separately reported that music giant Sony BMG has used software hiding techniques more commonly found in rootkits to prevent removal of the company's copy protection software. A rootkit is software that hides its presence on a computer while controlling critical system functions, and security professionals have lately warned that the addition of the technology to a variety of Internet threats - from bots to spyware - makes the malicious code more difficult to find and remove.

Both antivirus firm F-Secure and security information site SysInternals.com identified the copy protection scheme deployed by Sony BMG as essentially a rootkit. The tactic abuses the trust of the computer user, said Mikko Hippönen, chief research officer for F-Secure.

"No one reads the licensing agreements, and even if you do, (the Sony BMG agreement) does not make it obvious what is happening," he said. "It's also not obvious that it is almost impossible to uninstall the program." The concerns are the latest backlash against music and movie companies over what many critics call heavy-handed tactics designed to maintain the status quo in the face of innovative technologies that are disrupting the copyright holders' traditional business models. The industries' tactics have varied from frequent lawsuits against consumers to lobbying Congress for harsher penalties against those who use file-sharing technologies. Meanwhile, some vigilantes have poisoned peer-to-peer file sharing systems with Trojan horse programs that report the user.

The latest tactic, however, hews much closer than past actions to the definition of a malicious threat to a user's computer system, said Edward Felten, a professor of computer science and public affairs at Princeton University and an expert in digital-rights management technology. "It is not legitimate to undermine the user's desire to secure their own computer," Felten said. "I don't think they should be hiding files and programs and registry entries from the system administrator, ever." Answering critics, Sony BMG released on Wednesday a limited statement on its site and also posted a patch that Windows users can run using Internet Explorer to remove the copy-protection software from their system. Neither First 4 Internet or Sony BMG returned requests for comment on the issue.

"The protection software simply acts to prevent unlimited copying and ripping from discs featuring this protection solution," Sony BMG said in a statement posted on its site. "It is otherwise inactive. The software does not collect any personal information nor is it designed to be intrusive to your computer system."

Both F-Secure and SysInternals discovered the software after detecting the presence of a rootkit on a system that had played a content protected CD. After investigating, researchers at both organizations found that the root cause of the problem was the software installed by U.K.-based First 4 Internet. The software, known as XCP, also indiscriminately hides registry keys - the values used by the Windows operating system to run, configure and maintain software on the system - allowing malicious code to use the copy-protection software to hide itself.

Moreover, mimicking a tactic used by spyware and adware, the copy-protection software cannot be uninstalled under Windows XP except by contacting Sony BMG through a special Web site. For SysInternals.com's Mark Russinovich, the software is taking copy protection to an unpalatable extreme.

"Not only had Sony put software on my system that uses techniques commonly used by malware to mask its presence, the software is poorly written and provides no means for uninstall," he wrote after describing his investigation. "Worse, most users that stumble across the cloaked files with a (rootkit detector) scan will cripple their computer if they attempt the obvious step of deleting the cloaked files. While I believe in the media industry’s right to use copy protection mechanisms to prevent illegal copying, I don’t think that we’ve found the right balance of fair use and copy protection, yet."

However, the surreptitious software has had a broad effect. The content protection scheme has been included with tens of thousands of CDs. Using Google, a search of Amazon.com for "CONTENT/COPY-PROTECTED CD"--the site's label for music CDs that include the First 4 Internet or similar protections--turns up 32,800 hits.

Consumers that have encountered the digital-content protection technologies have railed against the record companies. The comments on Amazon.com for the Van Zant disc bought by F-Secure to investigate the problem are almost entirely made up of complaints regarding the disk's copy protection and not reviews of the content of the CD. One reviewer complained that the copy protection breaks any backwards compatibility with older CD players and CD-ROM drives.

"All of this was bad enough but this new method takes the copy protection madness to a whole new level," wrote the reviewer. "You'd never pay anyone to install malware on your computer system, would you? But that's exactly what happens when you buy this CD."

One blogger described his frustration, but ultimate success, in getting music from a protected CD ripped into his iTunes library. Record label ATO has disavowed the copy protection placed on its CDs by Sony BMG in a press statement.

"Neither we nor our artists ever gave permission for the use of this technology, nor is it our distributor's opinion that they need our permission," the company said. "Wherever it is our decision, we will forego use of copy-protection, just as we have in the past." Perhaps the strongest condemnation for the technology is that it punishes the wrong people, F-Secure's Hyppönen said.

"In some way, I can understand why they are doing this - to protect their content and make sure their content protection system does not get hacked," he said. "But you are only alienating your buying customers - the people that are illegally downloading the music are not affected." In the end, that may be the technology's worst limitation.

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