WEBROOT – INSIGHTS INTO THREATS AND TRENDS FROM OUR INTERNET SECURITY EXPERTS
Category Archives: Stupid malware tricks
Most malware in circulation are Trojans, and resort to some form of trickery in order to get themselves executed. Sometimes these tricks are, well, dumb, don’t work, or otherwise find themselves worthy of derision and mockery. These are their stories. (DUM DUM!)
Last week, threat researcher and malware reverse-engineer Marco Giuliani wrote up a fairly technical description of a bootkit — a rootkit that infects the master boot record of the hard drive, making it very difficult to remove — called Popureb. Marco’s report made it clear that the bootkit does not require Windows users to format the hard drive and reinstall Windows from scratch, as Microsoft had initially claimed was required for victims of this drive-by infection.
Andrea Allevi, one of our developers who works under Marco’s direction, subsequently wrote a tool that can remove the bootkit from an infected computer, which we’re releasing today to the public. We don’t offer technical support for the tool, but it’s fairly straightforward to use: Just launch it on a system infected with Popureb.E, using an account with Administrator privileges. It will ask your permission to clean the infected MBR, and once you say ‘yes’ it’ll do the rest. You’re welcome!
The latest generation of a rapidly evolving family of kernel-mode rootkits called, variously, ZeroAccess or Max++, seems to get more powerful and effective with each new variant. The rootkit infects a random system driver, overwriting its code with its own, infected driver, and hijacks the storage driver chain in order to hide its presence on the disk. But its own self-protection mechanism is its most interesting characteristic: It lays a virtual tripwire.
I’ve written about this rootkit in a few recent blog posts and in a white paper. On an infected computer, this new driver sets up a device called \Device\svchost.exe, and stores a fake PE file called svchost.exe – get it? The path is \Device\svchost.exe\svchost.exe. The driver then attaches itself to the disk device stack. The driver creates a new system process, called svchost.exe, pointing to the path: \\Globalroot\Device\svchost.exe\svchost.exe. This fake process serves as a kind of trap, specifically looking for the types of file operations performed by security software.
When a typical security scanner tries to analyze the rootkit-created svchost.exe file, the rootkit queues an initialized APC into the scanner’s own process, then calls the ExitProcess() function — essentially forcing the scanner to kill itself. The rootkit’s effectiveness, however, is hindered by a weakness in the way the rootkit filtered disk I/O. As it turned out, we can easily bypass the filtering technique and get to the masked data. We’ve also reversed the code the rootkit uses to generate domain names it will contact for command-and-control, and have provided a list of the domains it will use in the months of July, 2011 and August, 2011 so network managers can protect themselves proactively.
The other morning, I walked into the office to find a slew of instant messaging buddy requests from total strangers. This isn’t unexpected: I frequently get buddy requests on IM accounts I maintain for research purposes that contain malicious URLs and other useful research data. But this was one request I wasn’t expecting.
The inquiry, written in both English and Russian, was simply an advertisement for “Organization of DDOS attacks” from an ICQ account that has not been used since the friend request came in. The somewhat perplexing offer claims the service offers “support online 24/7/365″ (finally, a DDOS service that works weekends and holidays, unlike those slacker DDOSers who only work during banker’s hours) and asks “You hurt? We got competition?“
Who’s this we you’re referring to, mister criminal mastermind?
The solicitation for business included a different ICQ user ID number than the one used to send the buddy request, as well as an email address. I’ve seen some strange solicitations for various kinds of business delivered this way, but never one so brazen over an ostensibly illegal (both in Russia and elsewhere) service.
It’s too bad I can’t tell the guy to just go DDOS himself, but the accounts used in the ad have all been shut down.
Last Wednesday, Microsoft published a blog post detailing a significant update to a piece of malware named Popureb. The malware adds code to the Master Boot Record, or MBR, a region of the hard disk that’s read by the PC during bootup, long before the operating system has had a chance to get started. Researchers sometimes refer to these kinds of malware as bootkits, or a rootkit which loads at such a low level during the boot process that it is invisible to the operating system, and therefore very difficult to remove.
Microsoft researcher Chun Feng detailed some of the new features of Popureb.E, which includes a very low-level hook into the Windows driver responsible for disk writes and reads. When the driver on an infected system detects an attempt to write changes into the MBR — the kinds of changes a repair tool might try to make — it simply changes the command from write to read, effectively neutering any kind of tool running within Windows that might try to fix the infection.
Microsoft’s initial cleanup guidance on Popureb.E was pretty drastic, and more than a little scary: Full removal of the bootkit requires a full reinstall of Windows, wiping out anything currently on the hard drive. We don’t think this is the case, and the Microsoft folks seem to have moderated their advice to include some manual fixes using the recovery console.
While the whole concept behind the Trojan is valid and technically powerful, the practical implementation of the malware is not as valid as the idea behind it. What follows is a fairly technical write-up that describes both the problem, and one solution we’ve come up with.
It can seem at times that the only people who like change are Internet attackers. And they don’t just like it—they need it. Technology’s rapid changes give cybercriminals new attack vectors to exploit, and new ways to turn a profit out of someone else’s misfortune.
Take phishing, for example. The concept is simple: Send an email disguised as a message from a bank, PayPal, or UPS. Wait for the user to click a link in the message, and enter their private details into a phishing site, and presto! The attacker attains financial or personal login details that can be used to commit fraud or theft.
Of course, it was only a matter of time before most people caught on to email scams. Users read again and again not to click on such links. Mail solutions became better at spotting phishing emails and filtering them into a junk email folder. Even free Web mail providers now catch the majority of these attacks.
Once cybercriminals noticed their traditional phishing approaches were returning lower response rates, they rapidly adjusted to new mediums. As a result, a new trend emerged: smishing (social media phishing) became the new trend in cyber attacks.
This week’s rogue, once again, mimics a system utility and not merely an antivirus product. Either way, the scam is the same: Convince the victim that their computer is broken, then coerce them to pay for useless snake oil.
These rogue system utilities go by the names Windows Troubles Killer or Windows Salvage System; They are, for all intents and purposes, identical programs which have been “skinned” with different names. They actually appear to be a hybrid rogue, carefully blending a customized mix of malarkey and baloney into some sort of shenanigans smoothie. The program claims not only to be able to scan your computer for problems with software settings and other system optimization-sounding stuff, but also to perform some sort of check of your “Computer Safety” and “Network Security.” Oh yes, and there’s an antivirus component too, just to round out the complete package.
All in all, it’s a fairly rudimentary rogue to remove (whether you choose to do it manually or use our software), but it performs some unique system modifications that disable some legitimate security software, turns off some important Windows features, mimics some of Microsoft’s own software, and generally acts as a nuisance while reducing the actual security level of an infected computer. I’ll detail those after the jump. Continue reading →
As if we didn’t have enough to deal with this week — after a Microsoft patch Tuesday that brought with it a boatload of security updates for Windows, Office, Silverlight, Visual Studio, and other programs — some enterprising malware distributor is emailing around bogus tracking number malware dressed up in the icon of a PDF document, and that malware is downloading payloads named after the updaters that Windows Update retrieves during an update.
The malware arrived into one of our spam collection points with an attachment named UPS_document.zip. Way to be original there, criminals. Inside the Zip file was an executable downloader named UPS_Document.exe. Upon execution, it retrieves at least three payloads, including a copy of SpyEye (a password stealing Trojan), a tiny agent sending profiling information about the infected system, and a fraudulent “rogue system utility” called (on my XP testbed) Windows XP Restore.
The rogue takes on much of the appearance of a previous Rogue of the Week, named Windows Recovery. In fact, Windows XP Restore looks to be a very slightly modified duplicate of that software. If you’ve been hit with either rogue, there are some cool free tools for you to download that will repair some of the damage; Read on for details.
Most of yesterday, Threat Research Analyst Armando Orozco and I took a closer look at a piece of malware discovered by a university security researcher, Xuxian Jiang of North Carolina State. The malicious code, which the malware creator named Plankton, is embedded into a number of apps that were briefly posted to Google’s Android Market earlier this week, then rapidly pulled down after the researchers informed Google of their initial findings.
The Plankton code appears in a number of applications that were all focused on the popular game series Angry Birds. Some of the samples we looked at came as Android apps with names like Angry Birds Rio Unlocker v1.0, Angry Birds Multi User v1.00 or Angry Birds Cheater Trainer Helper V2.0.
When executed, the program displays the following text on the screen:
Simply click on the button below to unlock ALL levels in Angry Birds Rio. This will not delete your scores but might change the number of pineapples and bananas you have
None of the programs function as advertised. Instead, the malicious apps install additional code into the Android device into which they’re installed. These additional functions provide remote access and control of the Android device to, presumably, the distributor of the malicious apps, whose identity remains unknown at this time.
When malware ends up on an infected machine, one of the first things it will do is to ensure that it will start up again after the victim reboots their computer. For a criminal it makes sense. After all, what good is malware that stops working after a reboot?
In Windows, there are tons of ways for malware to accomplish this small but critical task, most of which involve the Registry. Technical folks call the Registry keys that are used for this purpose load points or auto-start locations. There’s even a pretty good free app from Microsoft that will show you everything configured to start itself up using any of these load points.
The Threat Research Analysts here use their knowledge of load points to fine-tune definitions. Increasingly, we have to kill a load point then reboot the computer to remove a piece of malware. I wanted to call attention to some odd load point trends, where load points are stacked like dominoes, so the action that starts the execution process is several steps removed from the actual execution.
This week, we turn our attention temporarily away from the never-ending stream of rogue security products on the Windows platform and take a closer look at the Mac OS analogue, MacProtector (aka Mac Security, Mac Defender, MacGuard, and–if history serves–soon to be many, many other names).
There’s been a lot of press coverage of these rogues — including a video blog post by us — in the past few weeks, so we thought it was high time we took a deeper dive.
Even though Webroot doesn’t offer an automated removal solution for the Mac, there’s good news for most Mac users — with only a little bit of effort, it’s fairly rudimentary to simply delete the rogue .app and be done with it. In this case, the Activity Monitor (Apple’s GUI process monitor, located by default in the Utilities folder inside the Applications folder) is your best friend.
The program appears as a stub .mpkg installer, which means that the application that installs the program isn’t a container with the full program stuffed inside. The installer drops an app named avRunner.app into the Applications directory, then executes it.