Entries Tagged "malware"

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CME in Practice

CME is “Common Malware Enumeration,” and it’s an initiave by US-CERT to give all worms, viruses, and such uniform names. The problem is that different security vendors use different names for the same thing, and it can be extremely confusing for customers. A uniform naming system is a great idea. (I blogged about this in September.)

Here’s someone talking about how it’s not working very well in practice. Basically, while you can go from a vendor’s site to the CME information, you can’t go from the CME information to a vendor’s site. This essentially makes it worthless: just another name and number without references.

Posted on December 6, 2005 at 3:21 PMView Comments

Benevolent Worms

Yet another story about benevolent worms and how they can secure our networks. This idea shows up every few years. (I wrote about it in 2000, and again in 2003. This quote (emphasis mine) from the article shows what the problem is:

Simulations show that the larger the network grows, the more efficient this scheme should be. For example, if a network has 50,000 nodes (computers), and just 0.4% of those are honeypots, just 5% of the network will be infected before the immune system halts the virus, assuming the fix works properly. But, a 200-million-node network ­ with the same proportion of honeypots ­ should see just 0.001% of machines get infected.

This is from my 2003 essay:

A worm is not “bad” or “good” depending on its payload. Viral propagation mechanisms are inherently bad, and giving them beneficial payloads doesn’t make things better. A worm is no tool for any rational network administrator, regardless of intent.

A good software distribution mechanism has the following characteristics:

  1. People can choose the options they want.
  2. Installation is adapted to the host it’s running on.
  3. It’s easy to stop an installation in progress, or uninstall the software.
  4. It’s easy to know what has been installed where.

A successful worm, on the other hand, runs without the consent of the user. It has a small amount of code, and once it starts to spread, it is self-propagating, and will keep going automatically until it’s halted.

These characteristics are simply incompatible. Giving the user more choice, making installation flexible and universal, allowing for uninstallation—all of these make worms harder to propagate. Designing a better software distribution mechanism, makes it a worse worm, and vice versa. On the other hand, making the worm quieter and less obvious to the user, making it smaller and easier to propagate, and making it impossible to contain, all make for bad software distribution.

All of this makes worms easy to get wrong and hard to recover from. Experimentation, most of it involuntary, proves that worms are very hard to debug successfully: in other words, once worms starts spreading it’s hard to predict exactly what they will do. Some viruses were written to propagate harmlessly, but did damage—ranging from crashed machines to clogged networks—because of bugs in their code. Many worms were written to do damage and turned out to be harmless (which is even more revealing).

Intentional experimentation by well-meaning system administrators proves that in your average office environment, the code that successfully patches one machine won’t work on another. Indeed, sometimes the results are worse than any threat of external attack. Combining a tricky problem with a distribution mechanism that’s impossible to debug and difficult to control is fraught with danger. Every system administrator who’s ever distributed software automatically on his network has had the “I just automatically, with the press of a button, destroyed the software on hundreds of machines at once!” experience. And that’s with systems you can debug and control; self-propagating systems don’t even let you shut them down when you find the problem. Patching systems is fundamentally a human problem, and beneficial worms are a technical solution that doesn’t work.

Posted on December 5, 2005 at 2:50 PMView Comments

A Science-Fiction Movie-Plot Threat

This has got to be the most bizarre movie-plot threat to date: alien viruses downloaded via the SETI project:

In his [Richard Carrigan, a particle physicist at the US Fermi National Accelerator Laboratory in Illinois] report, entitled “Do potential Seti signals need to be decontaminated?”, he suggests the Seti scientists may be too blase about finding a signal. “In science fiction, all the aliens are bad, but in the world of science, they are all good and simply want to get in touch.” His main concern is that, intentionally or otherwise, an extra-terrestrial signal picked up by the Seti team could cause widespread damage to computers if released on to the internet without being checked.

Here’s his website.

Although you have to admit, it could make a cool movie

EDITED TO ADD (12/16): Here’s a good rebuttal.

Posted on November 29, 2005 at 7:16 AMView 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

Hackers and Criminals

More evidence that hackers are migrating into crime:

Since then, organised crime units have continued to provide a fruitful income for a group of hackers that are effectively on their payroll. Their willingness to pay for hacking expertise has also given rise to a new subset of hackers. These are not hardcore criminals in pursuit of defrauding a bank or duping thousands of consumers. In one sense, they are the next generation of hackers that carry out their activities in pursuit of credibility from their peers and the ‘buzz’ of hacking systems considered to be unbreakable.

Where they come into contact with serious criminals is through underworld forums and chatrooms, where their findings are published and they are paid effectively for their intellectual property. This form of hacking – essentially ‘hacking for hire’ – is becoming more common with hackers trading zero-day exploit information, malcode, bandwidth, identities and toolkits underground for cash. So a hacker might package together a Trojan that defeats the latest version of an anti-virus client and sell that to a hacking community sponsored by criminals.

Posted on November 17, 2005 at 12:25 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

The Zotob Worm

If you’ll forgive the possible comparison to hurricanes, Internet epidemics are much like severe weather: they happen randomly, they affect some segments of the population more than others, and your previous preparation determines how effective your defense is.

Zotob was the first major worm outbreak since MyDoom in January 2004. It happened quickly—less than five days after Microsoft published a critical security bulletin (its 39th of the year). Zotob’s effects varied greatly from organization to organization: some networks were brought to their knees, while others didn’t even notice.

The worm started spreading on Sunday, 14 August. Honestly, it wasn’t much of a big deal, but it got a lot of play in the press because it hit several major news outlets, most notably CNN. If a news organization is personally affected by something, it’s much more likely to report extensively on it. But my company, Counterpane Internet Security, monitors more than 500 networks worldwide, and we didn’t think it was worth all the press coverage.

By the 17th, there were at least a dozen other worms that exploited the same vulnerability, both Zotob variants and others that were completely different. Most of them tried to recruit computers for bot networks, and some of the different variants warred against each other—stealing “owned” computers back and forth. If your network was infected, it was a mess.

Two weeks later, the 18-year-old who wrote the original Zotob worm was arrested, along with the 21-year-old who paid him to write it. It seems likely the person who funded the worm’s creation was not a hacker, but rather a criminal looking to profit.

The nature of worms has changed in the past few years. Previously, hackers looking for prestige or just wanting to cause damage were responsible for most worms. Today, they’re increasingly written or commissioned by criminals. By taking over computers, worms can send spam, launch denial-of-service extortion attacks, or search for credit-card numbers and other personal information.

What could you have done beforehand to protect yourself against Zotob and its kin? “Install the patch” is the obvious answer, but it’s not really a satisfactory one. There are simply too many patches. Although a single computer user can easily set up patches to automatically download and install—at least Microsoft Windows system patches—large corporate networks can’t. Far too often, patches cause other things to break.

It would be great to know which patches are actually important and which ones just sound important. Before that weekend in August, the patch that would have protected against Zotob was just another patch; by Monday morning, it was the most important thing a sysadmin could do to secure the network.

Microsoft had six new patches available on 9 August, three designated as critical (including the one that Zotob used), one important, and two moderate. Could you have guessed beforehand which one would have actually been critical? With the next patch release, will you know which ones you can put off and for which ones you need to drop everything, test, and install across your network?

Given that it’s impossible to know what’s coming beforehand, how you respond to an actual worm largely determines your defense’s effectiveness. You might need to respond quickly, and you most certainly need to respond accurately. Because it’s impossible to know beforehand what the necessary response should be, you need a process for that response. Employees come and go, so the only thing that ensures a continuity of effective security is a process. You need accurate and timely information to fuel this process. And finally, you need experts to decipher the information, determine what to do, and implement a solution.

The Zotob storm was both typical and unique. It started soon after the vulnerability was published, but I don’t think that made a difference. Even worms that use six-month-old vulnerabilities find huge swaths of the Internet unpatched. It was a surprise, but they all are.

This essay will appear in the November/December 2005 issue of IEEE Security & Privacy.

Posted on November 11, 2005 at 7:46 AMView Comments

Fraudulent Stock Transactions

From a Business Week story:

During July 13-26, stocks and mutual funds had been sold, and the proceeds wired out of his account in six transactions of nearly $30,000 apiece. Murty, a 64-year-old nuclear engineering professor at North Carolina State University, could only think it was a mistake. He hadn’t sold any stock in months.

Murty dialed E*Trade the moment its call center opened at 7 a.m. A customer service rep urged him to change his password immediately. Too late. E*Trade says the computer in Murty’s Cary (N.C.) home lacked antivirus software and had been infected with code that enabled hackers to grab his user name and password.

The cybercriminals, pretending to be Murty, directed E*Trade to liquidate his holdings. Then they had the brokerage wire the proceeds to a phony account in his name at Wells Fargo Bank. The New York-based online broker says the wire instructions appeared to be legit because they contained the security code the company e-mailed to Murty to execute the transaction. But the cyberthieves had gained control of Murty’s e-mail, too.

E*Trade recovered some of the money from the Wells Fargo account and returned it to Murty. In October, the Indian-born professor reached what he calls a satisfactory settlement with the firm, which says it did nothing wrong.

That last clause is critical. E*trade insists it did nothing wrong. It executed $174,000 in fraudulent transactions, but it did nothing wrong. It sold stocks without the knowledge or consent of the owner of those stocks, but it did nothing wrong.

Now quite possibly, E*trade did nothing wrong legally. There may very well be a paragraph buried in whatever agreement this guy signed that says something like: “You agree that any trade request that comes to us with the right password, whether it came from you or not, will be processed.” But there’s the market failure. Until we fix that, these losses are an externality to E*Trade. They’ll only fix the problem up to the point where customers aren’t leaving them in droves, not to the point where the customers’ stocks are secure.

Posted on November 10, 2005 at 2:40 PMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.