Entries Tagged "rootkits"

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"Lessons from the Sony CD DRM Episode"

“Lessons from the Sony CD DRM Episode” is an interesting paper by J. Alex Halderman and Edward W. Felten.

Abstract: In the fall of 2005, problems discovered in two Sony-BMG compact disc copy protection systems, XCP and MediaMax, triggered a public uproar that ultimately led to class-action litigation and the recall of millions of discs. We present an in-depth analysis of these technologies, including their design, implementation, and deployment. The systems are surprisingly complex and suffer from a diverse array of flaws that weaken their content protection and expose users to serious security and privacy risks. Their complexity, and their failure, makes them an interesting case study of digital rights management that carries valuable lessons for content companies, DRM vendors, policymakers, end users, and the security community.

Posted on February 17, 2006 at 2:11 PMView Comments

The Sony Rootkit Saga Continues

I’m just not able to keep up with all the twists and turns in this story. (My previous posts are here, here, here, and here, but a way better summary of the events is on BoingBoing: here, here, and here. Actually, you should just read every post on the topic in Freedom to Tinker. This is also worth reading.)

Many readers pointed out to me that the DMCA is one of the reasons antivirus companies aren’t able to disable invasive copy-protection systems like Sony’s rootkit: it may very well be illegal for them to do so. (Adam Shostack made this point.)

Here are two posts about the rootkit before Russinovich posted about it.

And it turns out you can easily defeat the rootkit:

With a small bit of tape on the outer edge of the CD, the PC then treats the disc as an ordinary single-session music CD and the commonly used music “rip” programs continue to work as usual.

(Original here.)

The fallout from this has been simply amazing. I’ve heard from many sources that the anti-copy-protection forces in Sony and other companies have newly found power, and that copy-protection has been set back years. Let’s hope that the entertainment industry realizes that digital copy protection is a losing game here, and starts trying to make money by embracing the characteristics of digital technology instead of fighting against them. I’ve written about that here and here (both from 2001).

Even Foxtrot has a cartoon on the topic.

I think I’m done here. Others are covering this much more extensively than I am. Unless there’s a new twist that I simply have to comment on….

EDITED TO ADD (11/21): The EFF is suing Sony. (The page is a good summary of the whole saga.)

EDITED TO ADD (11/22): Here’s a great idea; Sony can use a feature of the rootkit to inform infected users that they’re infected.

As it turns out, there’s a clear solution: A self-updating messaging system already built into Sony’s XCP player. Every time a user plays a XCP-affected CD, the XCP player checks in with Sony’s server. As Russinovich explained, usually Sony’s server sends back a null response. But with small adjustments on Sony’s end — just changing the output of a single script on a Sony web server — the XCP player can automatically inform users of the software improperly installed on their hard drives, and of their resulting rights and choices.

This is so obviously the right thing to do. My guess is that it’ll never happen.

Texas is suing Sony. According to the official statement:

The suit is also the first filed under the state’s spyware law of 2005. It alleges the company surreptitiously installed the spyware on millions of compact music discs (CDs) that consumers inserted into their computers when they play the CDs, which can compromise the systems.

And here’s something I didn’t know: the rootkit consumes 1% – 2% of CPU time, whether or not you’re playing a Sony CD. You’d think there would be a “theft of services” lawsuit in there somewhere.

EDITED TO ADD (11/30): Business Week has a good article on the topic.

Posted on November 21, 2005 at 4:34 PMView Comments

Sony's DRM Rootkit: The Real Story

This is my sixth column for Wired.com:

It’s a David and Goliath story of the tech blogs defeating a mega-corporation.

On Oct. 31, Mark Russinovich broke the story in his blog: Sony BMG Music Entertainment distributed a copy-protection scheme with music CDs that secretly installed a rootkit on computers. This software tool is run without your knowledge or consent — if it’s loaded on your computer with a CD, a hacker can gain and maintain access to your system and you wouldn’t know it.

The Sony code modifies Windows so you can’t tell it’s there, a process called “cloaking” in the hacker world. It acts as spyware, surreptitiously sending information about you to Sony. And it can’t be removed; trying to get rid of it damages Windows.

This story was picked up by other blogs (including mine), followed by the computer press. Finally, the mainstream media took it up.

The outcry was so great that on Nov. 11, Sony announced it was temporarily halting production of that copy-protection scheme. That still wasn’t enough — on Nov. 14 the company announced it was pulling copy-protected CDs from store shelves and offered to replace customers’ infected CDs for free.

But that’s not the real story here.

It’s a tale of extreme hubris. Sony rolled out this incredibly invasive copy-protection scheme without ever publicly discussing its details, confident that its profits were worth modifying its customers’ computers. When its actions were first discovered, Sony offered a “fix” that didn’t remove the rootkit, just the cloaking.

Sony claimed the rootkit didn’t phone home when it did. On Nov. 4, Thomas Hesse, Sony BMG’s president of global digital business, demonstrated the company’s disdain for its customers when he said, “Most people don’t even know what a rootkit is, so why should they care about it?” in an NPR interview. Even Sony’s apology only admits that its rootkit “includes a feature that may make a user’s computer susceptible to a virus written specifically to target the software.”

However, imperious corporate behavior is not the real story either.

This drama is also about incompetence. Sony’s latest rootkit-removal tool actually leaves a gaping vulnerability. And Sony’s rootkit — designed to stop copyright infringement — itself may have infringed on copyright. As amazing as it might seem, the code seems to include an open-source MP3 encoder in violation of that library’s license agreement. But even that is not the real story.

It’s an epic of class-action lawsuits in California and elsewhere, and the focus of criminal investigations. The rootkit has even been found on computers run by the Department of Defense, to the Department of Homeland Security’s displeasure. While Sony could be prosecuted under U.S. cybercrime law, no one thinks it will be. And lawsuits are never the whole story.

This saga is full of weird twists. Some pointed out how this sort of software would degrade the reliability of Windows. Someone created malicious code that used the rootkit to hide itself. A hacker used the rootkit to avoid the spyware of a popular game. And there were even calls for a worldwide Sony boycott. After all, if you can’t trust Sony not to infect your computer when you buy its music CDs, can you trust it to sell you an uninfected computer in the first place? That’s a good question, but — again — not the real story.

It’s yet another situation where Macintosh users can watch, amused (well, mostly) from the sidelines, wondering why anyone still uses Microsoft Windows. But certainly, even that is not the real story.

The story to pay attention to here is the collusion between big media companies who try to control what we do on our computers and computer-security companies who are supposed to be protecting us.

Initial estimates are that more than half a million computers worldwide are infected with this Sony rootkit. Those are amazing infection numbers, making this one of the most serious internet epidemics of all time — on a par with worms like Blaster, Slammer, Code Red and Nimda.

What do you think of your antivirus company, the one that didn’t notice Sony’s rootkit as it infected half a million computers? And this isn’t one of those lightning-fast internet worms; this one has been spreading since mid-2004. Because it spread through infected CDs, not through internet connections, they didn’t notice? This is exactly the kind of thing we’re paying those companies to detect — especially because the rootkit was phoning home.

But much worse than not detecting it before Russinovich’s discovery was the deafening silence that followed. When a new piece of malware is found, security companies fall over themselves to clean our computers and inoculate our networks. Not in this case.

McAfee didn’t add detection code until Nov. 9, and as of Nov. 15 it doesn’t remove the rootkit, only the cloaking device. The company admits on its web page that this is a lousy compromise. “McAfee detects, removes and prevents reinstallation of XCP.” That’s the cloaking code. “Please note that removal will not impair the copyright-protection mechanisms installed from the CD. There have been reports of system crashes possibly resulting from uninstalling XCP.” Thanks for the warning.

Symantec’s response to the rootkit has, to put it kindly, evolved. At first the company didn’t consider XCP malware at all. It wasn’t until Nov. 11 that Symantec posted a tool to remove the cloaking. As of Nov. 15, it is still wishy-washy about it, explaining that “this rootkit was designed to hide a legitimate application, but it can be used to hide other objects, including malicious software.”

The only thing that makes this rootkit legitimate is that a multinational corporation put it on your computer, not a criminal organization.

You might expect Microsoft to be the first company to condemn this rootkit. After all, XCP corrupts Windows’ internals in a pretty nasty way. It’s the sort of behavior that could easily lead to system crashes — crashes that customers would blame on Microsoft. But it wasn’t until Nov. 13, when public pressure was just too great to ignore, that Microsoft announced it would update its security tools to detect and remove the cloaking portion of the rootkit.

Perhaps the only security company that deserves praise is F-Secure, the first and the loudest critic of Sony’s actions. And Sysinternals, of course, which hosts Russinovich’s blog and brought this to light.

Bad security happens. It always has and it always will. And companies do stupid things; always have and always will. But the reason we buy security products from Symantec, McAfee and others is to protect us from bad security.

I truly believed that even in the biggest and most-corporate security company there are people with hackerish instincts, people who will do the right thing and blow the whistle. That all the big security companies, with over a year’s lead time, would fail to notice or do anything about this Sony rootkit demonstrates incompetence at best, and lousy ethics at worst.

Microsoft I can understand. The company is a fan of invasive copy protection — it’s being built into the next version of Windows. Microsoft is trying to work with media companies like Sony, hoping Windows becomes the media-distribution channel of choice. And Microsoft is known for watching out for its business interests at the expense of those of its customers.

What happens when the creators of malware collude with the very companies we hire to protect us from that malware?

We users lose, that’s what happens. A dangerous and damaging rootkit gets introduced into the wild, and half a million computers get infected before anyone does anything.

Who are the security companies really working for? It’s unlikely that this Sony rootkit is the only example of a media company using this technology. Which security company has engineers looking for the others who might be doing it? And what will they do if they find one? What will they do the next time some multinational company decides that owning your computers is a good idea?

These questions are the real story, and we all deserve answers.

EDITED TO ADD (11/17): Slashdotted.

EDITED TO ADD (11/19): Details of Sony’s buyback program. And more GPL code was stolen and used in the rootkit.

Posted on November 17, 2005 at 9:08 AM

Still More on Sony's DRM Rootkit

This story is just getting weirder and weirder (previous posts here and here).

Sony already said that they’re stopping production of CDs with the embedded rootkit. Now they’re saying that they will pull the infected disks from stores and offer free exchanges to people who inadvertently bought them.

Sony BMG Music Entertainment said Monday it will pull some of its most popular CDs from stores in response to backlash over copy-protection software on the discs.

Sony also said it will offer exchanges for consumers who purchased the discs, which contain hidden files that leave them vulnerable to computer viruses when played on a PC.

That’s good news, but there’s more bad news. The patch Sony is distributing to remove the rootkit opens a huge security hole:

The root of the problem is a serious design flaw in Sony’s web-based uninstaller. When you first fill out Sony’s form to request a copy of the uninstaller, the request form downloads and installs a program – an ActiveX control created by the DRM vendor, First4Internet – called CodeSupport. CodeSupport remains on your system after you leave Sony’s site, and it is marked as safe for scripting, so any web page can ask CodeSupport to do things. One thing CodeSupport can be told to do is download and install code from an Internet site. Unfortunately, CodeSupport doesn’t verify that the downloaded code actually came from Sony or First4Internet. This means any web page can make CodeSupport download and install code from any URL without asking the user’s permission.

Even more interesting is that there may be at least half a million infected computers:

Using statistical sampling methods and a secret feature of XCP that notifies Sony when its CDs are placed in a computer, [security researcher Dan] Kaminsky was able to trace evidence of infections in a sample that points to the probable existence of at least one compromised machine in roughly 568,200 networks worldwide. This does not reflect a tally of actual infections, however, and the real number could be much higher.

I say “may be at least” because the data doesn’t smell right to me. Look at the list of infected titles, and estimate what percentage of CD buyers will play them on their computers; does that seem like half a million sales to you? It doesn’t to me, although I readily admit that I don’t know the music business. Their methodology seems sound, though:

Kaminsky discovered that each of these requests leaves a trace that he could follow and track through the internet’s domain name system, or DNS. While this couldn’t directly give him the number of computers compromised by Sony, it provided him the number and location (both on the net and in the physical world) of networks that contained compromised computers. That is a number guaranteed to be smaller than the total of machines running XCP.

His research technique is called DNS cache snooping, a method of nondestructively examining patterns of DNS use. Luis Grangeia invented the technique, and Kaminsky became famous in the security community for refining it.

Kaminsky asked more than 3 million DNS servers across the net whether they knew the addresses associated with the Sony rootkit — connected.sonymusic.com, updates.xcp-aurora.com and license.suncom2.com. He uses a “non-recursive DNS query” that allows him to peek into a server’s cache and find out if anyone else has asked that particular machine for those addresses recently.

If the DNS server said yes, it had a cached copy of the address, which means that at least one of its client computers had used it to look up Sony’s digital-rights-management site. If the DNS server said no, then Kaminsky knew for sure that no Sony-compromised machines existed behind it.

The results have surprised Kaminsky himself: 568,200 DNS servers knew about the Sony addresses. With no other reason for people to visit them, that points to one or more computers behind those DNS servers that are Sony-compromised. That’s one in six DNS servers, across a statistical sampling of a third of the 9 million DNS servers Kaminsky estimates are on the net.

In any case, Sony’s rapid fall from grace is a great example of the power of blogs; it’s been fifteen days since Mark Russinovich first posted about the rootkit. In that time the news spread like a firestorm, first through the blogs, then to the tech media, and then into the mainstream media.

Posted on November 15, 2005 at 3:16 PMView Comments

More on Sony's DRM Rootkit

Here’s the story, edited to add lots of news.

There will be lawsuits. (Here’s the first.) Police are getting involved. There’s a Trojan that uses Sony’s rootkit to hide. And today Sony temporarily halted production of CDs protected with this technology.

Sony really overreached this time. I hope they get slapped down hard for it.

EDITED TO ADD (13 Nov): More information on uninstalling the rootkit. And Microsoft will update its security tools to detect and remove the rootkit. That makes a lot of sense. If Windows crashes because of this — and others of this ilk — Microsoft will be blamed.

Posted on November 11, 2005 at 12:23 PMView Comments

Sony Secretly Installs Rootkit on Computers

Mark Russinovich discovered a rootkit on his system. After much analysis, he discovered that the rootkit was installed as a part of the DRM software linked with a CD he bought. The package cannot be uninstalled. Even worse, the package actively cloaks itself from process listings and the file system.

At that point I knew conclusively that the rootkit and its associated files were related to the First 4 Internet DRM software Sony ships on its CDs. Not happy having underhanded and sloppily written software on my system I looked for a way to uninstall it. However, I didn’t find any reference to it in the Control Panel’s Add or Remove Programs list, nor did I find any uninstall utility or directions on the CD or on First 4 Internet’s site. I checked the EULA and saw no mention of the fact that I was agreeing to have software put on my system that I couldn’t uninstall. Now I was mad.

Removing the rootkit kills Windows.

Could Sony have violated the the Computer Misuse Act in the UK? If this isn’t clearly in the EULA, they have exceeded their privilege on the customer’s system by installing a rootkit to hide their software.

Certainly Mark has a reasonable lawsuit against Sony in the U.S.

EDITED TO ADD: The Washington Post is covering this story.

Sony lies about their rootkit:

November 2, 2005 – This Service Pack removes the cloaking technology component that has been recently discussed in a number of articles published regarding the XCP Technology used on SONY BMG content protected CDs. This component is not malicious and does not compromise security. However to alleviate any concerns that users may have about the program posing potential security vulnerabilities, this update has been released to enable users to remove this component from their computers.

Their update does not remove the rootkit, it just gets rid of the $sys$ cloaking.

Ed Felton has a great post on the issue:

The update is more than 3.5 megabytes in size, and it appears to contain new versions of almost all the files included in the initial installation of the entire DRM system, as well as creating some new files. In short, they’re not just taking away the rootkit-like function — they’re almost certainly adding things to the system as well. And once again, they’re not disclosing what they’re doing.

No doubt they’ll ask us to just trust them. I wouldn’t. The companies still assert — falsely — that the original rootkit-like software “does not compromise security” and “[t]here should be no concern” about it. So I wouldn’t put much faith in any claim that the new update is harmless. And the companies claim to have developed “new ways of cloaking files on a hard drive”. So I wouldn’t derive much comfort from carefully worded assertions that they have removed “the … component .. that has been discussed”.

And you can use the rootkit to avoid World of Warcraft spyware.

World of Warcraft hackers have confirmed that the hiding capabilities of Sony BMG’s content protection software can make tools made for cheating in the online world impossible to detect.

.

EDITED TO ADD: F-Secure makes a good point:

A member of our IT security team pointed out quite chilling thought about what might happen if record companies continue adding rootkit based copy protection into their CDs.

In order to hide from the system a rootkit must interface with the OS on very low level and in those areas theres no room for error.

It is hard enough to program something on that level, without having to worry about any other programs trying to do something with same parts of the OS.

Thus if there would be two DRM rootkits on the same system trying to hook same APIs, the results would be highly unpredictable. Or actually, a system crash is quite predictable result in such situation.

EDITED TO ADD: Declan McCullagh has a good essay on the topic. There will be lawsuits.

EDITED TO ADD: The Italian police are getting involved.

EDITED TO ADD: Here’s a Trojan that uses Sony’s rootkit to hide.

EDITED TO ADD: Sony temporarily halts production of CDs protected with this technology.

Posted on November 1, 2005 at 10:17 AMView Comments

GhostBuster

This is a really interesting technical report from Microsoft. It describes a clever prototype — called GhostBuster — they developed for detecting arbitrary persistent and stealthy software, such as rootkits, Trojans, and software keyloggers. It’s a really elegant idea, based on a simple observation: the rootkit must exist on disk to be persistent, but must lie to programs running within the infected OS in order to hide.

Here’s how it works: The user has the GhostBuster program on a CD. He sticks the CD in the drive, and from within the (possibly corrupted) OS, the checker program runs: stopping all other user programs, flushing the caches, and then doing a complete checksum of all files on the disk and a scan of any registry keys that could autostart the system, writing out the results to a file on the hard drive.

Then the user is instructed to press the reset button, the CD boots its own OS, and the scan is repeated. Any differences indicate a rootkit or other stealth software, without the need for knowing what particular rootkits are or the proper checksums for the programs installed on disk.

Simple. Clever. Elegant.

In order to fool GhostBuster, the rootkit must 1) detect that such a checking program is running and either not lie to it or change the output as it’s written to disk (in the limit this becomes the halting problem for the rootkit designer), 2) integrate into the BIOS rather than the OS (tricky, platform specific, and not always possible), or 3) give up on either being persistent or stealthy. Thus this doesn’t eliminate rootkits entirely, but is a pretty mortal blow to persistent rootkits.

Of course, the concept could be adopted for any other operating system as well.

This is a great idea, but there’s a huge problem. GhostBuster is only a research prototype, so you can’t get a copy. And, even worse, Microsoft has no plans to turn it into a commercial tool.

This is too good an idea to abandon. Microsoft, if you’re listening, you should release this tool to the world. Make it public domain. Make it open source, even. It’s a great idea, and you deserve credit for coming up with it.

Any other security companies listening? Make and sell one of these. Anyone out there looking for an open source project? Here’s a really good one.

Note: I have no idea if Microsoft patented this idea. If they did and they don’t release it, shame on them. If they didn’t, good for them.

Posted on February 15, 2005 at 8:00 AMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.