New IRS Site Could Make it Easy for Thieves to Intercept Some Stimulus Payments

April 10, 2020
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The U.S. federal government is now in the process of sending Economic Impact Payments by direct deposit to millions of Americans. Most who are eligible for payments can expect to have funds direct-deposited into the same bank accounts listed on previous years’ tax filings sometime next week. Today, the Internal Revenue Service (IRS) stood up a site to collect bank account information from the many Americans who don’t usually file a tax return. The question is, will those non-filers have a chance to claim their payments before fraudsters do?

The IRS says the Economic Impact Payment will be $1,200 for individual or head of household filers, and $2,400 for married filing jointly if they are not a dependent of another taxpayer and have a work eligible Social Security number with adjusted gross income up to:

  • $75,000 for individuals
  • $112,500 for head of household filers and
  • $150,000 for married couples filing joint returns

Taxpayers with higher incomes will receive more modest payments (reduced by $5 for each $100 above the $75,000/$112,500/$150,000 thresholds). Most people who who filed a tax return in 2018 and/or 2019 and provided their bank account information for a debit or credit should soon see an Economic Impact Payment direct-deposited into their bank accounts. Likewise, people drawing Social Security payments from the government will receive stimulus payments the same way.

But there are millions of U.S. residents — including low-income workers and certain veterans and individuals with disabilities — who aren’t required to file a tax return but who are still eligible to receive at least a $1,200 stimulus payment. And earlier today, the IRS unveiled a Web site where it is asking those non-filers to provide their bank account information for direct deposits.

However, the possibility that fraudsters may intercept payments to these individuals seems very real, given the relatively lax identification requirements of this non-filer portal and the high incidence of tax refund fraud in years past. Each year, scam artists file phony tax refund requests on millions of Americans, regardless of whether or not the impersonated taxpayer is actually due a refund. In most cases, the victim only finds out when he or she goes to file their taxes and has the return rejected because it has already been filed by scammers.

In this case, fraudsters would simply need to identify the personal information for a pool of Americans who don’t normally file tax returns, which may well include a large number of people who are disabled, poor or simply do not have easy access to a computer or the Internet. Armed with this information, the scammers need only provide the target’s name, address, date of birth and Social Security number, and then supply their own bank account information to claim at least $1,200 in electronic payments.

Page 1 of 2 in the IRS stimulus payment application page for non-filers.

Unfortunately, SSN and DOB data is not secret, nor is it hard to come by. As noted in countless stories here, there are multiple shops in the cybercrime underground that sell SSN and DOB data on tens of millions of Americans for a few dollars per record.

A review of the Web site set up to accept bank account information for the stimulus payments reveals few other mandatory identity checks to complete the filing process. It appears that all applicants need to provide a mobile phone number and verify they can receive text messages at that number, but beyond that the rest of the identity checks seem to be optional. Continue reading →

Microsoft Buys Corp.com So Bad Guys Can’t

April 7, 2020
65 Comments

In February, KrebsOnSecurity told the story of a private citizen auctioning off the dangerous domain corp.com for the starting price of $1.7 million. Domain experts called corp.com dangerous because years of testing showed whoever wields it would have access to an unending stream of passwords, email and other sensitive data from hundreds of thousands of Microsoft Windows PCs at major companies around the globe. This week, Microsoft Corp. agreed to buy the domain in a bid to keep it out of the hands of those who might abuse its awesome power.

Wisconsin native Mike O’Connor, who bought corp.com 26 years ago but has done very little with it since, said he hoped Microsoft would buy it because hundreds of thousands of confused Windows PCs are constantly trying to share sensitive data with corp.com. Also, early versions of Windows actually encouraged the adoption of insecure settings that made it more likely Windows computers might try to share sensitive data with corp.com.

From February’s piece:

At issue is a problem known as “namespace collision,” a situation where domain names intended to be used exclusively on an internal company network end up overlapping with domains that can resolve normally on the open Internet.

Windows computers on an internal corporate network validate other things on that network using a Microsoft innovation called Active Directory, which is the umbrella term for a broad range of identity-related services in Windows environments. A core part of the way these things find each other involves a Windows feature called “DNS name devolution,” which is a kind of network shorthand that makes it easier to find other computers or servers without having to specify a full, legitimate domain name for those resources.

For instance, if a company runs an internal network with the name internalnetwork.example.com, and an employee on that network wishes to access a shared drive called “drive1,” there’s no need to type “drive1.internalnetwork.example.com” into Windows Explorer; typing “\\drive1\” alone will suffice, and Windows takes care of the rest.

But things can get far trickier with an internal Windows domain that does not map back to a second-level domain the organization actually owns and controls. And unfortunately, in early versions of Windows that supported Active Directory — Windows 2000 Server, for example — the default or example Active Directory path was given as “corp,” and many companies apparently adopted this setting without modifying it to include a domain they controlled.

Compounding things further, some companies then went on to build (and/or assimilate) vast networks of networks on top of this erroneous setting.

Now, none of this was much of a security concern back in the day when it was impractical for employees to lug their bulky desktop computers and monitors outside of the corporate network. But what happens when an employee working at a company with an Active Directory network path called “corp” takes a company laptop to the local Starbucks?

Chances are good that at least some resources on the employee’s laptop will still try to access that internal “corp” domain. And because of the way DNS name devolution works on Windows, that company laptop online via the Starbucks wireless connection is likely to then seek those same resources at “corp.com.”

In practical terms, this means that whoever controls corp.com can passively intercept private communications from hundreds of thousands of computers that end up being taken outside of a corporate environment which uses this “corp” designation for its Active Directory domain.

The story went on to describe how years of testing — some of which was subsidized by grants from the U.S. Department of Homeland Security — showed hundreds of thousands of Windows computers were constantly trying to send this domain information it had no business receiving, including attempts to log in to internal corporate networks and access specific file shares on those networks.

O’Connor told me he was selling the domain after doing basically nothing with it for 26 years because he was getting on in years and didn’t want his kids to inherit this mess. When he put the domain up for sale, I asked if he’d agree to let me know if and when he sold it.

On Monday evening, he wrote to say that Microsoft had agreed to purchase it. O’Connor said he could  not discuss the terms of the deal, nor could he offer further comment beyond acknowledging the sale of corp.com to Microsoft. Continue reading →

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‘War Dialing’ Tool Exposes Zoom’s Password Problems

April 2, 2020
76 Comments

As the Coronavirus pandemic continues to force people to work from home, countless companies are now holding daily meetings using videoconferencing services from Zoom. But without the protection of a password, there’s a decent chance your next Zoom meeting could be “Zoom bombed” — attended or disrupted by someone who doesn’t belong. And according to data gathered by a new automated Zoom meeting discovery tool dubbed “zWarDial,” a crazy number of meetings at major corporations are not being protected by a password.

zWarDial, an automated tool for finding non-password protected Zoom meetings. According to its makers, zWarDial can find on average 110 meetings per hour, and has a success rate of around 14 percent.

Each Zoom conference call is assigned a Meeting ID that consists of 9 to 11 digits. Naturally, hackers have figured out they can simply guess or automate the guessing of random IDs within that space of digits.

Security experts at Check Point Research did exactly that last summer, and found they were able to predict approximately four percent of randomly generated Meeting IDs. The Check Point researchers said enabling passwords on each meeting was the only thing that prevented them from randomly finding a meeting.

Zoom responded by saying it was enabling passwords by default in all future scheduled meetings. Zoom also said it would block repeated attempts to scan for meeting IDs, and that it would no longer automatically indicate if a meeting ID was valid or invalid.

Nevertheless, the incidence of Zoombombing has skyrocketed over the past few weeks, even prompting an alert by the FBI on how to secure meetings against eavesdroppers and mischief-makers. This suggests that many Zoom users have disabled passwords by default and/or that Zoom’s new security feature simply isn’t working as intended for all users.

New data and acknowledgments by Zoom itself suggest the latter may be more likely.

Earlier this week, KrebsOnSecurity heard from Trent Lo, a security professional and co-founder of SecKC, Kansas City’s longest-running monthly security meetup. Lo and fellow SecKC members recently created zWarDial, which borrows part of its name from the old phone-based war dialing programs that called random or sequential numbers in a given telephone number prefix to search for computer modems.

Lo said zWarDial evades Zoom’s attempts to block automated meeting scans by routing the searches through multiple proxies in Tor, a free and open-source software that lets users browse the Web anonymously.

“Zoom recently said they fixed this but I’m using a totally different URL and passing a cookie along with that URL,” Lo said, describing part of how the tool works on the back end. “This gives me the [Zoom meeting] room information without having to log in.”

Lo said a single instance of zWarDial can find approximately 100 meetings per hour, but that multiple instances of the tool running in parallel could probably discover most of the open Zoom meetings on any given day. Each instance, he said, has a success rate of approximately 14 percent, meaning for each random meeting number it tries, the program has a 14 percent chance of finding an open meeting.

Only meetings that are protected by a password are undetectable by zWarDial, Lo said.

“Having a password enabled on the meeting is the only thing that defeats it,” he said.

Lo shared the output of one day’s worth of zWarDial scanning, which revealed information about nearly 2,400 upcoming or recurring Zoom meetings. That information included the link needed to join each meeting; the date and time of the meeting; the name of the meeting organizer; and any information supplied by the meeting organizer about the topic of the meeting.

The results were staggering, and revealed details about Zoom meetings scheduled by some of the world’s largest companies, including major banks, international consulting firms, ride-hailing services, government contractors, and investment ratings firms.

KrebsOnSecurity is not naming the companies involved, but was able to verify dozens of them by matching the name of the meeting organizer with corporate profiles on LinkedIn.

By far the largest group of companies exposing their Zoom meetings are in the technology sector, and include a number of security and cloud technology vendors. These include at least one tech company that’s taken to social media warning people about the need to password protect Zoom meetings!

The distribution of Zoom meetings found by zWarDial, indexed by industry. As depicted above, zWarDial found roughly 2,400 exposed meetings in less than 24 hours. Image: SecKC.

Continue reading →

Phish of GoDaddy Employee Jeopardized Escrow.com, Among Others

March 31, 2020
32 Comments

A spear-phishing attack this week hooked a customer service employee at GoDaddy.com, the world’s largest domain name registrar, KrebsOnSecurity has learned. The incident gave the phisher the ability to view and modify key customer records, access that was used to change domain settings for a half-dozen GoDaddy customers, including transaction brokering site escrow.com.

Escrow.com helps people safely broker all sorts of transactions online (ironically enough, brokering domain sales is a big part of its business). For about two hours starting around 5 p.m. PT Monday evening, Escrow.com’s website looked radically different: Its homepage was replaced with a crude message in plain text:

The profanity-laced message left behind by whoever briefly hijacked the DNS records for escrow.com. Image: Escrow.com

DomainInvesting.com’s Elliot Silver picked up on the change and got a statement from Matt Barrie, the CEO of freelancer.com, which owns escrow.com.

“During the incident, the hackers changed the DNS records for Escrow.com to point to to a third party web server,” Barrie wrote, noting that his security team managed to talk to the hacker responsible for the hijack via telephone.

Barrie said escrow.com would be sharing more details about the incident in the coming days, but he emphasized that no escrow.com systems were compromised, and no customer data, funds or domains were compromised.

KrebsOnSecurity reached out to Barrie and escrow.com with some follow-up questions, and immediately after that pinged Chris Ueland, CEO of SecurityTrails, a company that helps customers keep track of their digital assets.

Ueland said after hearing about the escrow.com hack Monday evening he pulled the domain name system (DNS) records for escrow.com and saw they were pointing to an Internet address in Malaysia — 111.90.149[.]49 (that address is hobbled here because it is currently flagged as hosting a phishing site). The attacker also obtained free encryption certificates for escrow.com from Let’s Encrypt.

Running a reverse DNS lookup on this 111.90.149[.]49 address shows it is tied to fewer than a dozen domains, including a 12-day-old domain that invokes the name of escrow.com’s registrar — servicenow-godaddy[.]com. Sure enough, loading that domain in a browser reveals the same text that appeared Monday night on escrow.com, minus the redaction above.

The message at servicenow-godaddy[.]com was identical to the one displayed by escrow.com while the site’s DNS records were hacked.

It was starting to look like someone had gotten phished. Then I heard back from Matt Barrie, who said it wasn’t anyone at escrow.com that got phished. Barrie said the hacker was able to read messages and notes left on escrow.com’s account at GoDaddy that only GoDaddy employees should have been able to see.

Barrie said one of those notes stated that certain key changes for escrow.com could only be made after calling a specific phone number and receiving verbal authorization. As it happened, the attacker went ahead and called that number, evidently assuming he was calling someone at GoDaddy.

In fact, the name and number belonged to escrow.com’s general manager, who played along for more than an hour talking to the attacker while recording the call and coaxing information out of him.

“This guy had access to the notes, and knew the number to call,” to make changes to the account, Barrie said. “He was literally reading off the tickets to the notes of the admin panel inside GoDaddy.”

A DNS lookup on escrow.com Monday evening via the Windows PowerShell built into Windows 10. Image: SecurityTrails

In a statement shared with KrebsOnSecurity, GoDaddy acknowledged that on March 30 the company was alerted to a security incident involving a customer’s domain name. An investigation revealed a GoDaddy employee had fallen victim to a spear-phishing attack, and that five other customer accounts were “potentially” affected — although GoDaddy wouldn’t say which or how many domains those customer accounts may have with GoDaddy. Continue reading →

Annual Protest to ‘Fight Krebs’ Raises €150K+

March 30, 2020
55 Comments

In 2018, KrebsOnSecurity unmasked the creators of Coinhive — a now-defunct cryptocurrency mining service that was being massively abused by cybercriminals — as the administrators of a popular German language image-hosting forum. In protest of that story, forum members donated hundreds of thousands of euros to nonprofits that combat cancer (Krebs means “cancer” in German). This week, the forum is celebrating its third annual observance of that protest to “fight Krebs,” albeit with a Coronavirus twist.

Images posted to the decidedly not-safe-for-work German-language image forum pr0gramm[.]com. Members have posted a large number of ‘thank you’ receipts from cancer research organizations that benefited from their fight cancer/krebs campaign.

On March 26, 2018, KrebsOnSecurity published Who and What is Coinhive, which showed the founder of Coinhive was the co-creator of the German forum pr0gramm[dot]com (not safe for work).  I undertook the research because Coinhive’s code at the time was found on tens of thousands of hacked Web sites, and Coinhive seemed uninterested in curbing widespread abuse of its platform.

Pr0gramm’s top members accused KrebsOnSecurity of violating their privacy, even though all of the research published about them was publicly available online. In protest, the forum’s leaders urged members to donate money to medical research in a bid to find a cure for Krebs (i.e. “cancer”). They ended up raising more than a quarter-million dollars worth of donations from members.

Last year’s commemoration of the protest fundraiser — dubbed “Krebsaction” by Pr0gramm — raised almost $300,000 for anti-cancer research groups. Interestingly, Coinhive announced it was shutting down around the same time as that second annual fundraiser.

This year’s Krebsaction started roughly three days ago and so far has raised more than 150,000 euros (~$165,000), with many Pr0gramm members posting screenshots of their online donations. The primary beneficiary appears to be DKMS, a German nonprofit that works to combat various blood cancers, such as leukemia and lymphoma.

The pr0gramm post kicking off this year’s “Krebsaction” fundraiser.

This year, however, Pr0gramm’s administrators exhorted forum members to go beyond just merely donating money to a worthy cause, and encouraged them to do something to help those most affected by the COVID-19/Coronavirus pandemic.

“This year pr0gramm-members shall not only donate but do a good act in terms of corona (and prove it), for example bring food to old people, bring proof of volunteering and such stuff,” reads the Pr0gramm image kicking off this year’s Krebsaction.  The message further states, “Posts mit geringem Einsatz können wir nicht akzeptieren,” which translates roughly to “Posts with little effort we cannot accept.”

Russians Shut Down Huge Card Fraud Ring

March 26, 2020
36 Comments

Federal investigators in Russia have charged at least 25 people accused of operating a sprawling international credit card theft ring. Cybersecurity experts say the raid included the charging of a major carding kingpin thought to be tied to dozens of carding shops and to some of the bigger data breaches targeting western retailers over the past decade.

In a statement released this week, the Russian Federal Security Service (FSB) said 25 individuals were charged with circulating illegal means of payment in connection with some 90 websites that sold stolen credit card data.

A still image from a video of the raids released by the Russian FSB this week shows stacks of hundred dollar bills and cash counting machines seized at a residence of one of the accused.

The FSB has not released a list of those apprehended, but the agency’s statement came several days after details of the raids were first leaked on the LiveJournal blog of cybersecurity blogger Andrey Sporov. The post claimed that among those apprehended was the infamous cybercriminal Alexey Stroganov, who goes by the hacker names “Flint” and “Flint24.”

According to cyber intelligence firm Intel 471, Stroganov has been a long-standing member of major underground forums since at least 2001. In 2006, Stroganov and an associate Gerasim Selivanov (a.k.a. “Gabrik“) were sentenced to six years of confinement in Russia, but were set free just two years into their sentence. Intel 471 says Selivanov also was charged along with Stroganov in this past week’s law enforcement action.

“Our continuous monitoring of underground activity revealed despite the conviction, Flint24 never left the cybercrime scene,” reads an analysis penned by Intel 471.

“You can draw your own conclusions [about why he was released early],” Sporaw wrote, suggesting that perhaps the accused bribed someone to get out of jail before his sentence was up.

Flint is among the biggest players in the crowded underground market for stolen credit card data, according to a U.S. law enforcement source who asked to remain anonymous because he was not authorized to speak to the media. The source described Flint’s role as that of a wholesaler of credit card data stolen in some of the biggest breaches at major Western retailers.

“He moved hundreds of millions of dollars through BTC-e,” the source said, referring to a cryptocurrency exchange that was seized by U.S. authorities in 2017. “Flint had a piece of almost every major hack because in many cases it was his guys doing it. Whether or not his marketplaces sold it, his crew had a role in a lot of the big breaches over the last ten years.”

Intel 471’s analysis seemed to support that conclusion, noting that Flint worked closely with other major carding shops that were not his, and that he associated with a number of cybercrooks who regularly bought stolen credit cards in batches of 100,000 pieces at once.

Top denizens of several cybercrime forums who’ve been tracking the raids posited that Stroganov and others were busted because they had a habit of violating the golden rule for criminal hackers residing in Russia or in a former Soviet country: Don’t target your own country’s people and/or banks. Continue reading →

US Government Sites Give Bad Security Advice

March 25, 2020
57 Comments

Many U.S. government Web sites now carry a message prominently at the top of their home pages meant to help visitors better distinguish between official U.S. government properties and phishing pages. Unfortunately, part of that message is misleading and may help perpetuate a popular misunderstanding about Web site security and trust that phishers have been exploiting for years now.

For example, the official U.S. Census Bureau website https://my2020census.gov carries a message that reads, “An official Web site of the United States government. Here’s how you know.” Clicking the last part of that statement brings up a panel with the following information:

A message displayed at the top of many U.S. .gov Web sites.

The text I have a beef with is the bit on the right, beneath the “This site is secure” statement. Specifically, it says, “The https:// ensures that you are connecting to the official website….”

Here’s the deal: The https:// part of an address (also called “Secure Sockets Layer” or SSL) merely signifies the data being transmitted back and forth between your browser and the site is encrypted and cannot be read by third parties.

However, the presence of “https://” or a padlock in the browser address bar does not mean the site is legitimate, nor is it any proof the site has been security-hardened against intrusion from hackers.

In other words, while readers should never transmit sensitive information to a site that does not use https://, the presence of this security feature tells you nothing about the trustworthiness of the site in question.

Here’s a sobering statistic: According to PhishLabs, by the end of 2019 roughly three-quarters (74 percent) of all phishing sites were using SSL certificates. PhishLabs found this percentage increased from 68% in Q3 and 54% in Q2 of 2019. Continue reading →

Who’s Behind the ‘Web Listings’ Mail Scam?

March 23, 2020
33 Comments

In December 2018, KrebsOnSecurity looked at how dozens of U.S. political campaigns, cities and towns had paid a shady company called Web Listings Inc. after receiving what looked like a bill for search engine optimization (SEO) services rendered on behalf of their domain names. The story concluded that this dubious service had been scamming people and companies for more than a decade, and promised a Part II to explore who was behind Web Listings. What follows are some clues that point to a very convincing answer to that question.

Since at least 2007, Web Listings Inc. has been sending snail mail letters to domain registrants around the world. The missives appear to be an $85 bill for an “annual search engine listing” service. The notice does disclose that it is in fact a solicitation and not a bill, but wording of the notice asserts the recipient has already received the services in question.

Image: Better Business Bureau.

The mailer references the domain name web-listings.net, one of several similarly-named domains registered sometime in 2007 or later to a “James Madison,” who lists his address variously as a university in New Britain, Connecticut or a UPS Store mailbox in Niagara Falls, New York.

Some others include: weblistingservices.com, webservicescorp.net, websiteservicescorp.com, web-listingsinc.com, weblistingsinc.net, and weblistingsreports.net. At some point, each of these domains changes the owner’s name from James Madison to “Mark Carter.” As we’ll see, Mark is a name that comes up quite a bit in this investigation.

Image: Better Business Bureau.

A Twitter account for Web Listings Inc. has posts dating back to 2010, and points to even more Web Listings domains, including weblistingsinc.org. Cached versions of weblistingsinc.org at archive.org show logos similar to the one featured on the Web Listings mailer, and early versions of the site reference a number of “business partners” in India that also perform SEO services.

Searching the Internet for some of these Web listing domains mentioned in the company’s Twitter account brings up a series of press releases once issued on behalf of the company. One from May 2011 at onlineprnews.com sings the praises of Weblistingsinc.info, weblistingsinc.org and web-listings.net in the same release, and lists the point of contact simply as “Mark.”

Historic WHOIS registration records from Domaintools [an advertiser on this blog] say Weblistingsinc.org was registered in Nov. 2010 to a Mark Scott in Blairgowrie, Scotland, using the email address clientnews@reputationmanagementfor.com.

Reputationmanagementfor.com bills itself as an online service for “fighting negative and incorrect content on the internet,” which is especially interesting for reasons that should become clearer in a few paragraphs. The site says Mark Scott, 46, is an employee of Reputationmanagementfor.com, and that he is also involved with two other companies:

-GoBananas, a business that sets up group outings, with a focus on bachelor and bachelorette parties;

-HelpMeGo.to, an entity in Scotland that did online marketing and travel tourism both in Scotland (via sites like Scotland.org.uk and marketinghotelsonline.co.uk) and on India’s coastal Kerala state where HelpMeGo.to employed a number of people involved in the SEO business. Helpmego.to now simply redirects to GoBananas.

According to Farsight Security, a company that keeps historic records of which Web sites were hosted at which Internet addresses, Weblistingsinc.org was for a while hosted at the IP address 68.169.45.65 with just six other domains, including travelingalberta.com, which was a blog about traveling and living in Alberta, Canada registered to Mark Scott and the email address management@helpmego.to. Cached versions of this site from 2011 show it naming Web Listings Inc. as a business partner.

That same management@helpmego.to email address is tied to the WHOIS records for markscottblog.com, gobananas.co.uk, gobananas.com. Cached copies of markscottblog.com from 2010 at Archive.org show his profile page on blogger.com links to another blog with much the same content, images and links called internetmadness.blogspot.com.

Among the 2011 entries from the Internetmadness blog is a post promoting the wonders of benefits of Web Listings Inc.

A cached copy of Mark Scott’s blog Internet Madness from 2011 promotes Web Listings Inc.

Continue reading →

Security Breach Disrupts Fintech Firm Finastra

March 20, 2020
33 Comments

Finastra, a company that provides a range of technology solutions to banks worldwide, said today it was shutting down key systems in response to a security breach discovered this morning. The company’s public statement and notice to customers does not mention the cause of the outage, but their response so far is straight out of the playbook for dealing with ransomware attacks.

London-based Finastra has offices in 42 countries and reported more than $2 billion in revenues last year. The company employs more than 10,000 people and has over 9,000 customers across 130 countries — including nearly all of the top 50 banks globally.

Earlier today, sources at two different U.S. financial institutions forwarded a notice they received from Finastra saying the outage was expected to disrupt certain services, particularly for clients in North America.

“We wish to inform our valued customers that we are investigating a potential security breach. At 3:00 a.m. EST on March 20, 2020, we were alerted to anomalous activity on our network which risked the integrity of our data-centers,” reads the notice. “As such, and to protect our customers, we have taken quick and strict remedial action to contain and isolate the incident, while we investigate further.”

Update, 5:21 p.m. ET: Finastra has acknowledged that it is battling ransomware.

“At this time, we strongly believe that the incident was the result of a ransomware attack and do not have any evidence that customer or employee data was accessed or exfiltrated, nor do we believe our clients’ networks were impacted,” the company said in a revised statement.

Continue reading →

Zyxel Flaw Powers New Mirai IoT Botnet Strain

March 20, 2020
7 Comments

In February, hardware maker Zyxel fixed a zero-day vulnerability in its routers and VPN firewall products after KrebsOnSecurity told the company the flaw was being abused by attackers to break into devices. This week, security researchers said they spotted that same vulnerability being exploited by a new variant of Mirai, a malware strain that targets vulnerable Internet of Things (IoT) devices for use in large-scale attacks and as proxies for other cybercrime activity.

Security experts at Palo Alto Networks said Thursday their sensors detected the new Mirai variant — dubbed Mukashi — on Mar. 12. The new Mirai strain targets CVE-2020-9054, a critical flaw that exists in many VPN firewalls and network attached storage (NAS) devices made by Taiwanese vendor Zyxel Communication Corp., which boasts some 100 million devices deployed worldwide.

Like other Mirai variants, Mukashi constantly scans the Internet for vulnerable IoT devices like security cameras and digital video recorders (DVRs), looking for a range of machines protected only by factory-default credentials or commonly-picked passwords.

Palo Alto said IoT systems infected by Mukashi then report back to a control server, which can be used to disseminate new instructions — such as downloading additional software or launching distributed denial of service (DDoS) attacks.

The commands Mukashi botmasters can send to infected devices include scanning for and exploiting other systems, and launching DDoS attacks. Image: Palo Alto Networks.

Zyxel issued a patch for the flaw on Feb. 24, but the update did not fix the problem on many older Zyxel devices which are no longer being supported by the company. For those devices, Zyxel’s advice was not to leave them connected to the Internet.

A joint advisory on CVE-2020-9054 from the U.S. Department of Homeland Security and the CERT Coordination Center rates this vulnerability at a “10” — the most severe kind of flaw. The DHS/CERT advisory also includes sample code to test if a Zyxel product is vulnerable to the flaw.

My advice? If you can’t patch it, pitch it, as Mukashi is not the only thing interested in this Zyxel bug: Recent activity suggests attackers known for deploying ransomware have been actively working to test it for use against targets.