Entries Tagged "antivirus"

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US Government Exposes North Korean Malware

US Cyber Command has uploaded North Korean malware samples to the VirusTotal aggregation repository, adding to the malware samples it uploaded in February.

The first of the new malware variants, COPPERHEDGE, is described as a Remote Access Tool (RAT) “used by advanced persistent threat (APT) cyber actors in the targeting of cryptocurrency exchanges and related entities.”

This RAT is known for its capability to help the threat actors perform system reconnaissance, run arbitrary commands on compromised systems, and exfiltrate stolen data.

TAINTEDSCRIBE is a trojan that acts as a full-featured beaconing implant with command modules and designed to disguise as Microsoft’s Narrator.

The trojan “downloads its command execution module from a command and control (C2) server and then has the capability to download, upload, delete, and execute files; enable Windows CLI access; create and terminate processes; and perform target system enumeration.”

Last but not least, PEBBLEDASH is yet another North Korean trojan acting like a full-featured beaconing implant and used by North Korean-backed hacking groups “to download, upload, delete, and execute files; enable Windows CLI access; create and terminate processes; and perform target system enumeration.”

It’s interesting to see the US government take a more aggressive stance on foreign malware. Making samples public, so all the antivirus companies can add them to their scanning systems, is a big deal — and probably required some complicated declassification maneuvering.

Me, I like reading the codenames.

Lots more on the US-CERT website.

Posted on May 14, 2020 at 6:29 AMView Comments

Signed Malware

Stuxnet famously used legitimate digital certificates to sign its malware. A research paper from last year found that the practice is much more common than previously thought.

Now, researchers have presented proof that digitally signed malware is much more common than previously believed. What’s more, it predated Stuxnet, with the first known instance occurring in 2003. The researchers said they found 189 malware samples bearing valid digital signatures that were created using compromised certificates issued by recognized certificate authorities and used to sign legitimate software. In total, 109 of those abused certificates remain valid. The researchers, who presented their findings Wednesday at the ACM Conference on Computer and Communications Security, found another 136 malware samples signed by legitimate CA-issued certificates, although the signatures were malformed.

The results are significant because digitally signed software is often able to bypass User Account Control and other Windows measures designed to prevent malicious code from being installed. Forged signatures also represent a significant breach of trust because certificates provide what’s supposed to be an unassailable assurance to end users that the software was developed by the company named in the certificate and hasn’t been modified by anyone else. The forgeries also allow malware to evade antivirus protections. Surprisingly, weaknesses in the majority of available AV programs prevented them from detecting known malware that was digitally signed even though the signatures weren’t valid.

Posted on February 2, 2018 at 6:38 AMView Comments

WannaCry Ransomware

Criminals go where the money is, and cybercriminals are no exception.

And right now, the money is in ransomware.

It’s a simple scam. Encrypt the victim’s hard drive, then extract a fee to decrypt it. The scammers can’t charge too much, because they want the victim to pay rather than give up on the data. But they can charge individuals a few hundred dollars, and they can charge institutions like hospitals a few thousand. Do it at scale, and it’s a profitable business.

And scale is how ransomware works. Computers are infected automatically, with viruses that spread over the internet. Payment is no more difficult than buying something online ­– and payable in untraceable bitcoin -­- with some ransomware makers offering tech support to those unsure of how to buy or transfer bitcoin. Customer service is important; people need to know they’ll get their files back once they pay.

And they want you to pay. If they’re lucky, they’ve encrypted your irreplaceable family photos, or the documents of a project you’ve been working on for weeks. Or maybe your company’s accounts receivable files or your hospital’s patient records. The more you need what they’ve stolen, the better.

The particular ransomware making headlines is called WannaCry, and it’s infected some pretty serious organizations.

What can you do about it? Your first line of defense is to diligently install every security update as soon as it becomes available, and to migrate to systems that vendors still support. Microsoft issued a security patch that protects against WannaCry months before the ransomware started infecting systems; it only works against computers that haven’t been patched. And many of the systems it infects are older computers, no longer normally supported by Microsoft –­ though it did belatedly release a patch for those older systems. I know it’s hard, but until companies are forced to maintain old systems, you’re much safer upgrading.

This is easier advice for individuals than for organizations. You and I can pretty easily migrate to a new operating system, but organizations sometimes have custom software that breaks when they change OS versions or install updates. Many of the organizations hit by WannaCry had outdated systems for exactly these reasons. But as expensive and time-consuming as updating might be, the risks of not doing so are increasing.

Your second line of defense is good antivirus software. Sometimes ransomware tricks you into encrypting your own hard drive by clicking on a file attachment that you thought was benign. Antivirus software can often catch your mistake and prevent the malicious software from running. This isn’t perfect, of course, but it’s an important part of any defense.

Your third line of defense is to diligently back up your files. There are systems that do this automatically for your hard drive. You can invest in one of those. Or you can store your important data in the cloud. If your irreplaceable family photos are in a backup drive in your house, then the ransomware has that much less hold on you. If your e-mail and documents are in the cloud, then you can just reinstall the operating system and bypass the ransomware entirely. I know storing data in the cloud has its own privacy risks, but they may be less than the risks of losing everything to ransomware.

That takes care of your computers and smartphones, but what about everything else? We’re deep into the age of the “Internet of things.”

There are now computers in your household appliances. There are computers in your cars and in the airplanes you travel on. Computers run our traffic lights and our power grids. These are all vulnerable to ransomware. The Mirai botnet exploited a vulnerability in internet-enabled devices like DVRs and webcams to launch a denial-of-service attack against a critical internet name server; next time it could just as easily disable the devices and demand payment to turn them back on.

Re-enabling a webcam will be cheap; re-enabling your car will cost more. And you don’t want to know how vulnerable implanted medical devices are to these sorts of attacks.

Commercial solutions are coming, probably a convenient repackaging of the three lines of defense described above. But it’ll be yet another security surcharge you’ll be expected to pay because the computers and internet-of-things devices you buy are so insecure. Because there are currently no liabilities for lousy software and no regulations mandating secure software, the market rewards software that’s fast and cheap at the expense of good. Until that changes, ransomware will continue to be profitable line of criminal business.

This essay previously appeared in the New York Daily News.

Posted on May 19, 2017 at 6:10 AMView Comments

Credential Stealing as an Attack Vector

Traditional computer security concerns itself with vulnerabilities. We employ antivirus software to detect malware that exploits vulnerabilities. We have automatic patching systems to fix vulnerabilities. We debate whether the FBI should be permitted to introduce vulnerabilities in our software so it can get access to systems with a warrant. This is all important, but what’s missing is a recognition that software vulnerabilities aren’t the most common attack vector: credential stealing is.

The most common way hackers of all stripes, from criminals to hacktivists to foreign governments, break into networks is by stealing and using a valid credential. Basically, they steal passwords, set up man-in-the-middle attacks to piggy-back on legitimate logins, or engage in cleverer attacks to masquerade as authorized users. It’s a more effective avenue of attack in many ways: it doesn’t involve finding a zero-day or unpatched vulnerability, there’s less chance of discovery, and it gives the attacker more flexibility in technique.

Rob Joyce, the head of the NSA’s Tailored Access Operations (TAO) group — basically the country’s chief hacker — gave a rare public talk at a conference in January. In essence, he said that zero-day vulnerabilities are overrated, and credential stealing is how he gets into networks: “A lot of people think that nation states are running their operations on zero days, but it’s not that common. For big corporate networks, persistence and focus will get you in without a zero day; there are so many more vectors that are easier, less risky, and more productive.”

This is true for us, and it’s also true for those attacking us. It’s how the Chinese hackers breached the Office of Personnel Management in 2015. The 2014 criminal attack against Target Corporation started when hackers stole the login credentials of the company’s HVAC vendor. Iranian hackers stole US login credentials. And the hacktivist that broke into the cyber-arms manufacturer Hacking Team and published pretty much every proprietary document from that company used stolen credentials.

As Joyce said, stealing a valid credential and using it to access a network is easier, less risky, and ultimately more productive than using an existing vulnerability, even a zero-day.

Our notions of defense need to adapt to this change. First, organizations need to beef up their authentication systems. There are lots of tricks that help here: two-factor authentication, one-time passwords, physical tokens, smartphone-based authentication, and so on. None of these is foolproof, but they all make credential stealing harder.

Second, organizations need to invest in breach detection and — most importantly — incident response. Credential-stealing attacks tend to bypass traditional IT security software. But attacks are complex and multi-step. Being able to detect them in process, and to respond quickly and effectively enough to kick attackers out and restore security, is essential to resilient network security today.

Vulnerabilities are still critical. Fixing vulnerabilities is still vital for security, and introducing new vulnerabilities into existing systems is still a disaster. But strong authentication and robust incident response are also critical. And an organization that skimps on these will find itself unable to keep its networks secure.

This essay originally appeared on Xconomy.

EDITED TO ADD (5/23): Portuguese translation.

Posted on May 4, 2016 at 6:51 AMView Comments

Did Kaspersky Fake Malware?

Two former Kaspersky employees have accused the company of faking malware to harm rival antivirus products. They would falsely classify legitimate files as malicious, tricking other antivirus companies that blindly copied Kaspersky’s data into deleting them from their customers’ computers.

In one technique, Kaspersky’s engineers would take an important piece of software commonly found in PCs and inject bad code into it so that the file looked like it was infected, the ex-employees said. They would send the doctored file anonymously to VirusTotal.

Then, when competitors ran this doctored file through their virus detection engines, the file would be flagged as potentially malicious. If the doctored file looked close enough to the original, Kaspersky could fool rival companies into thinking the clean file was problematic as well.

[…]

The former Kaspersky employees said Microsoft was one of the rivals that were targeted because many smaller security companies followed the Redmond, Washington-based company’s lead in detecting malicious files. They declined to give a detailed account of any specific attack.

Microsoft’s antimalware research director, Dennis Batchelder, told Reuters in April that he recalled a time in March 2013 when many customers called to complain that a printer code had been deemed dangerous by its antivirus program and placed in “quarantine.”

Batchelder said it took him roughly six hours to figure out that the printer code looked a lot like another piece of code that Microsoft had previously ruled malicious. Someone had taken a legitimate file and jammed a wad of bad code into it, he said. Because the normal printer code looked so much like the altered code, the antivirus program quarantined that as well.

Over the next few months, Batchelder’s team found hundreds, and eventually thousands, of good files that had been altered to look bad.

Kaspersky denies it.

EDITED TO ADD (8/19): Here’s an October 2013 presentation by Microsoft on the attacks.

EDITED TO ADD (9/11): A dissenting opinion.

Posted on August 18, 2015 at 2:35 PMView Comments

Comparing the Security Practices of Experts and Non-Experts

New paper: “‘…no one can hack my mind’: Comparing Expert and Non-Expert Security Practices,” by Iulia Ion, Rob Reeder, and Sunny Consolvo.

Abstract: The state of advice given to people today on how to stay safe online has plenty of room for improvement. Too many things are asked of them, which may be unrealistic, time consuming, or not really worth the effort. To improve the security advice, our community must find out what practices people use and what recommendations, if messaged well, are likely to bring the highest benefit while being realistic to ask of people. In this paper, we present the results of a study which aims to identify which practices people do that they consider most important at protecting their security on-line. We compare self-reported security practices of non-experts to those of security experts (i.e., participants who reported having five or more years of experience working in computer security). We report on the results of two online surveys — ­one with 231 security experts and one with 294 MTurk participants­ — on what the practices and attitudes of each group are. Our findings show a discrepancy between the security practices that experts and non-experts report taking. For instance, while experts most frequently report installing software updates, using two-factor authentication and using a password manager to stay safe online, non-experts report using antivirus software, visiting only known websites, and changing passwords frequently.

Posted on July 30, 2015 at 2:21 PMView Comments

NSA and GCHQ Attacked Antivirus Companies

On Monday, the Intercept published a new story from the Snowden documents:

The spy agencies have reverse engineered software products, sometimes under questionable legal authority, and monitored web and email traffic in order to discreetly thwart anti-virus software and obtain intelligence from companies about security software and users of such software. One security software maker repeatedly singled out in the documents is Moscow-based Kaspersky Lab, which has a holding registered in the U.K., claims more than 270,000 corporate clients, and says it protects more than 400 million people with its products.

British spies aimed to thwart Kaspersky software in part through a technique known as software reverse engineering, or SRE, according to a top-secret warrant renewal request. The NSA has also studied Kaspersky Lab’s software for weaknesses, obtaining sensitive customer information by monitoring communications between the software and Kaspersky servers, according to a draft top-secret report. The U.S. spy agency also appears to have examined emails inbound to security software companies flagging new viruses and vulnerabilities.

Wired has a good article on the documents:

The documents…don’t describe actual computer breaches against the security firms, but instead depict a systematic campaign to reverse-engineer their software in order to uncover vulnerabilities that could help the spy agencies subvert it.

[…]

An NSA slide describing “Project CAMBERDADA” lists at least 23 antivirus and security firms that were in that spy agency’s sights. They include the Finnish antivirus firm F-Secure, the Slovakian firm Eset, Avast software from the Czech Republic. and Bit-Defender from Romania. Notably missing from the list are the American anti-virus firms Symantec and McAfee as well as the UK-based firm Sophos.

But antivirus wasn’t the only target of the two spy agencies. They also targeted their reverse-engineering skills against CheckPoint, an Israeli maker of firewall software, as well as commercial encryption programs and software underpinning the online bulletin boards of numerous companies. GCHQ, for example, reverse-engineered both the CrypticDisk program made by Exlade and the eDataSecurity system from Acer. The spy agency also targeted web forum systems like vBulletin and Invision Power Board­used by Sony Pictures, Electronic Arts, NBC Universal and others­as well as CPanel, a software used by GoDaddy for configuring its servers, and PostfixAdmin, for managing the Postfix email server software But that’s not all. GCHQ reverse-engineered Cisco routers, too, which allowed the agency’s spies to access “almost any user of the internet” inside Pakistan and “to re-route selective traffic” straight into the mouth of GCHQ’s collection systems.

There’s also this article from Ars Technica. Slashdot thread.

Kaspersky recently announced that it was the victim of Duqu 2.0, probably from Israel.

Posted on June 26, 2015 at 6:59 AMView Comments

BIOS Hacking

We’ve learned a lot about the NSA’s abilities to hack a computer’s BIOS so that the hack survives reinstalling the OS. Now we have a research presentation about it.

From Wired:

The BIOS boots a computer and helps load the operating system. By infecting this core software, which operates below antivirus and other security products and therefore is not usually scanned by them, spies can plant malware that remains live and undetected even if the computer’s operating system were wiped and re-installed.

[…]

Although most BIOS have protections to prevent unauthorized modifications, the researchers were able to bypass these to reflash the BIOS and implant their malicious code.

[…]

Because many BIOS share some of the same code, they were able to uncover vulnerabilities in 80 percent of the PCs they examined, including ones from Dell, Lenovo and HP. The vulnerabilities, which they’re calling incursion vulnerabilities, were so easy to find that they wrote a script to automate the process and eventually stopped counting the vulns it uncovered because there were too many.

From ThreatPost:

Kallenberg said an attacker would need to already have remote access to a compromised computer in order to execute the implant and elevate privileges on the machine through the hardware. Their exploit turns down existing protections in place to prevent re-flashing of the firmware, enabling the implant to be inserted and executed.

The devious part of their exploit is that they’ve found a way to insert their agent into System Management Mode, which is used by firmware and runs separately from the operating system, managing various hardware controls. System Management Mode also has access to memory, which puts supposedly secure operating systems such as Tails in the line of fire of the implant.

From the Register:

“Because almost no one patches their BIOSes, almost every BIOS in the wild is affected by at least one vulnerability, and can be infected,” Kopvah says.

“The high amount of code reuse across UEFI BIOSes means that BIOS infection can be automatic and reliable.

“The point is less about how vendors don’t fix the problems, and more how the vendors’ fixes are going un-applied by users, corporations, and governments.”

From Forbes:

Though such “voodoo” hacking will likely remain a tool in the arsenal of intelligence and military agencies, it’s getting easier, Kallenberg and Kovah believe. This is in part due to the widespread adoption of UEFI, a framework that makes it easier for the vendors along the manufacturing chain to add modules and tinker with the code. That’s proven useful for the good guys, but also made it simpler for researchers to inspect the BIOS, find holes and create tools that find problems, allowing Kallenberg and Kovah to show off exploits across different PCs. In the demo to FORBES, an HP PC was used to carry out an attack on an ASUS machine. Kovah claimed that in tests across different PCs, he was able to find and exploit BIOS vulnerabilities across 80 per cent of machines he had access to and he could find flaws in the remaining 10 per cent.

“There are protections in place that are supposed to prevent you from flashing the BIOS and we’ve essentially automated a way to find vulnerabilities in this process to allow us to bypass them. It turns out bypassing the protections is pretty easy as well,” added Kallenberg.

The NSA has a term for vulnerabilities it think are exclusive to it: NOBUS, for “nobody but us.” Turns out that NOBUS is a flawed concept. As I keep saying: “Today’s top-secret programs become tomorrow’s PhD theses and the next day’s hacker tools.” By continuing to exploit these vulnerabilities rather than fixing them, the NSA is keeping us all vulnerable.

Two Slashdot threads. Hacker News thread. Reddit thread.

EDITED TO ADD (3/31): Slides from the CanSecWest presentation. The bottom line is that there are some pretty huge BIOS insecurities out there. We as a community and industry need to figure out how to regularly patch our BIOSes.

Posted on March 23, 2015 at 7:07 AMView Comments

Is Antivirus Dead?

Symantec declared anti-virus dead, and Brian Krebs writes a good response.

He’s right: antivirus won’t protect you from the ever-increasing percentage of malware that’s specifically designed to bypass antivirus software, but it will protect you from all the random unsophisticated attacks out there: the “background radiation” of the Internet.

Posted on May 15, 2014 at 1:18 PMView Comments

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Sidebar photo of Bruce Schneier by Joe MacInnis.