Posts Tagged: alex holden


10
Oct 20

Report: U.S. Cyber Command Behind Trickbot Tricks

A week ago, KrebsOnSecurity broke the news that someone was attempting to disrupt the Trickbot botnet, a malware crime machine that has infected millions of computers and is often used to spread ransomware. A new report Friday says the coordinated attack was part of an operation carried out by the U.S. military’s Cyber Command.

Image: Shutterstock.

On October 2, KrebsOnSecurity reported that twice in the preceding ten days, an unknown entity that had inside access to the Trickbot botnet sent all infected systems a command telling them to disconnect themselves from the Internet servers the Trickbot overlords used to control compromised Microsoft Windows computers.

On top of that, someone had stuffed millions of bogus records about new victims into the Trickbot database — apparently to confuse or stymie the botnet’s operators.

In a story published Oct. 9, The Washington Post reported that four U.S. officials who spoke on condition of anonymity said the Trickbot disruption was the work of U.S. Cyber Command, a branch of the Department of Defense headed by the director of the National Security Agency (NSA).

The Post report suggested the action was a bid to prevent Trickbot from being used to somehow interfere with the upcoming presidential election, noting that Cyber Command was instrumental in disrupting the Internet access of Russian online troll farms during the 2018 midterm elections.

The Post said U.S. officials recognized their operation would not permanently dismantle Trickbot, describing it rather as “one way to distract them for at least a while as they seek to restore their operations.” Continue reading →


2
Oct 20

Attacks Aimed at Disrupting the Trickbot Botnet

Over the past 10 days, someone has been launching a series of coordinated attacks designed to disrupt Trickbot, an enormous collection of more than two million malware-infected Windows PCs that are constantly being harvested for financial data and are often used as the entry point for deploying ransomware within compromised organizations.

A text snippet from one of the bogus Trickbot configuration updates. Source: Intel 471

On Sept. 22, someone pushed out a new configuration file to Windows computers currently infected with Trickbot. The crooks running the Trickbot botnet typically use these config files to pass new instructions to their fleet of infected PCs, such as the Internet address where hacked systems should download new updates to the malware.

But the new configuration file pushed on Sept. 22 told all systems infected with Trickbot that their new malware control server had the address 127.0.0.1, which is a “localhost” address that is not reachable over the public Internet, according to an analysis by cyber intelligence firm Intel 471.

It’s not known how many Trickbot-infected systems received the phony update, but it seems clear this wasn’t just a mistake by Trickbot’s overlords. Intel 471 found that it happened yet again on Oct. 1, suggesting someone with access to the inner workings of the botnet was trying to disrupt its operations.

“Shortly after the bogus configs were pushed out, all Trickbot controllers stopped responding correctly to bot requests,” Intel 471 wrote in a note to its customers. “This possibly means central Trickbot controller infrastructure was disrupted. The close timing of both events suggested an intentional disruption of Trickbot botnet operations.”

Intel 471 CEO Mark Arena said it’s anyone’s guess at this point who is responsible.

“Obviously, someone is trying to attack Trickbot,” Arena said. “It could be someone in the security research community, a government, a disgruntled insider, or a rival cybercrime group. We just don’t know at this point.

Arena said it’s unclear how successful these bogus configuration file updates will be given that the Trickbot authors built a fail-safe recovery system into their malware. Specifically, Trickbot has a backup control mechanism: A domain name registered on EmerDNS, a decentralized domain name system.

“This domain should still be in control of the Trickbot operators and could potentially be used to recover bots,” Intel 471 wrote.

But whoever is screwing with the Trickbot purveyors appears to have adopted a multi-pronged approach: Around the same time as the second bogus configuration file update was pushed on Oct. 1, someone stuffed the control networks that the Trickbot operators use to keep track of data on infected systems with millions of new records.

Alex Holden is chief technology officer and founder of Hold Security, a Milwaukee-based cyber intelligence firm that helps recover stolen data. Holden said at the end of September Trickbot held passwords and financial data stolen from more than 2.7 million Windows PCs.

By October 1, Holden said, that number had magically grown to more than seven million.

“Someone is flooding the Trickbot system with fake data,” Holden said. “Whoever is doing this is generating records that include machine names indicating these are infected systems in a broad range of organizations, including the Department of Defense, U.S. Bank, JP Morgan Chase, PNC and Citigroup, to name a few.” Continue reading →


27
Jul 20

Business ID Theft Soars Amid COVID Closures

Identity thieves who specialize in running up unauthorized lines of credit in the names of small businesses are having a field day with all of the closures and economic uncertainty wrought by the COVID-19 pandemic, KrebsOnSecurity has learned. This story is about the victims of a particularly aggressive business ID theft ring that’s spent years targeting small businesses across the country and is now pivoting toward using that access for pandemic assistance loans and unemployment benefits.

Most consumers are likely aware of the threat from identity theft, which occurs when crooks apply for new lines of credit in your name. But the same crime can be far more costly and damaging when thieves target small businesses. Unfortunately, far too many entrepreneurs are simply unaware of the threat or don’t know how to be watchful for it.

What’s more, with so many small enterprises going out of business or sitting dormant during the COVID-19 pandemic, organized fraud rings have an unusually rich pool of targets to choose from.

Short Hills, N.J.-based Dun & Bradstreet [NYSE:DNB] is a data analytics company that acts as a kind of de facto credit bureau for companies: When a business owner wants to open a new line of credit, creditors typically check with Dun & Bradstreet to gauge the business’s history and trustworthiness.

In 2019, Dun & Bradstreet saw more than a 100 percent increase in business identity theft. For 2020, the company estimates an overall 258 percent spike in the crime. Dun & Bradstreet said that so far this year it has received over 4,700 tips and leads where business identity theft or malfeasance are suspected.

“The ferocity of cyber criminals to take advantage of COVID-19 uncertainties by preying on small businesses is disturbing,” said Andrew LaMarca, who leads the global high-risk and fraud team at Dun & Bradstreet.

For the past several months, Milwaukee, Wisc. based cyber intelligence firm Hold Security has been monitoring the communications between and among a businesses ID theft gang apparently operating in Georgia and Florida but targeting businesses throughout the United States. That surveillance has helped to paint a detailed picture of how business ID thieves operate, as well as the tricks they use to gain credit in a company’s name.

Hold Security founder Alex Holden said the group appears to target both active and dormant or inactive small businesses. The gang typically will start by looking up the business ownership records at the Secretary of State website that corresponds to the company’s state of incorporation. From there, they identify the officers and owners of the company, acquire their Social Security and Tax ID numbers from the dark web and other sources online.

To prove ownership over the hijacked firms, they hire low-wage image editors online to help fabricate and/or modify a number of official documents tied to the business — including tax records and utility bills.

The scammers frequently then file phony documents with the Secretary of State’s office in the name(s) of the business owners, but include a mailing address that they control. They also create email addresses and domain names that mimic the names of the owners and the company to make future credit applications appear more legitimate, and submit the listings to business search websites, such as yellowpages.com.

For both dormant and existing businesses, the fraudsters attempt to create or modify the target company’s accounts at Dun & Bradstreet. In some cases, the scammers create dashboard accounts in the business’s names at Dun & Bradstreet’s credit builder portal; in others, the bad guys have actually hacked existing business accounts at DNB, requesting a new DUNS numbers for the business (a DUNS number is a unique, nine-digit identifier for businesses).

Finally, after the bogus profiles are approved by Dun & Bradstreet, the gang waits a few weeks or months and then starts applying for new lines of credit in the target business’s name at stores like Home Depot, Office Depot and Staples. Then they go on a buying spree with the cards issued by those stores.

Usually, the first indication a victim has that they’ve been targeted is when the debt collection companies start calling.

“They are using mostly small companies that are still active businesses but currently not operating because of COVID-19,” Holden said. “With this gang, we see four or five people working together. The team leader manages the work between people. One person seems to be in charge of getting stolen cards from the dark web to pay for the reactivation of businesses through the secretary of state sites. Another team member works on revising the business documents and registering them on various sites. The others are busy looking for specific businesses they want to revive.”

Holden said the gang appears to find success in getting new lines of credit with about 20 percent of the businesses they target.

“One’s personal credit is nothing compared to the ability of corporations to borrow money,” he said. “That’s bad because while the credit system may be flawed for individuals, it’s an even worse situation on average when we’re talking about businesses.”

Holden said over the past few months his firm has seen communications between the gang’s members indicating they have temporarily shifted more of their energy and resources to defrauding states and the federal government by filing unemployment insurance claims and apply for pandemic assistance loans with the Small Business Administration.

“It makes sense, because they’ve already got control over all these dormant businesses,” he said. “So they’re now busy trying to get unemployment payments and SBA loans in the names of these companies and their employees.”

PHANTOM OFFICES

Hold Security shared data intercepted from the gang that listed the personal and financial details of dozens of companies targeted for ID theft, including Dun & Bradstreet logins the crooks had created for the hijacked businesses. Dun & Bradstreet declined to comment on the matter, other than to say it was working with federal and state authorities to alert affected businesses and state regulators.

Among those targeted was Environmental Safety Consultants Inc. (ESC), a 37-year-old environmental engineering firm based in Bradenton, Fla. ESC owner Scott Russell estimates his company was initially targeted nearly two years ago, and that he first became aware something wasn’t right when he recently began getting calls from Home Depot’s corporate offices inquiring about the company’s delinquent account.

But Russell said he didn’t quite grasp the enormity of the situation until last year, when he was contacted by the manager of a virtual office space across town who told him about a suspiciously large number of deliveries at an office space that was rented out in his name.

Russell had never rented that particular office. Rather, the thieves had done it for him, using his name and the name of his business. The office manager said the deliveries came virtually non-stop, even though there was apparently no business operating within the rented premises. And in each case, shortly after the shipments arrived someone would show up and cart them away.

“She said we don’t think it’s you,” he recalled. “Turns out, they had paid for a lease in my name with someone else’s credit card. She shared with me a copy of the lease, which included a fraudulent ID and even a vehicle insurance card for a Land Cruiser we got rid of like 15 years ago. The application listed our home address with me and some woman who was not my wife’s name.”

The crates and boxes being delivered to his erstwhile office space were mostly computers and other high-priced items ordered from 10 different Office Depot credit cards that also were not in his name.

“The total value of the electronic equipment that was bought and delivered there was something like $75,000,” Russell said, noting that it took countless hours and phone calls with Office Depot to make it clear they would no longer accept shipments addressed to him or his company. “It was quite spine-tingling to see someone penned a lease in the name of my business and personal identity.”

Even though the virtual office manager had the presence of mind to take photocopies of the driver’s licenses presented by the people arriving to pick up the fraudulent shipments, the local police seemed largely uninterested in pursuing the case, Russell said.

“I went to the local county sheriff’s office and showed them all the documentation I had and the guy just yawned and said he’d get right on it,” he recalled. “The place where the office space was rented was in another county, and the detective I spoke to there about it was interested, but he could never get anyone from my county to follow up.” Continue reading →


9
Jun 20

Florence, Ala. Hit By Ransomware 12 Days After Being Alerted by KrebsOnSecurity

In late May, KrebsOnSecurity alerted numerous officials in Florence, Ala. that their information technology systems had been infiltrated by hackers who specialize in deploying ransomware. Nevertheless, on Friday, June 5, the intruders sprang their attack, deploying ransomware and demanding nearly $300,000 worth of bitcoin. City officials now say they plan to pay the ransom demand, in hopes of keeping the personal data of their citizens off of the Internet.

Nestled in the northwest corner of Alabama, Florence is home to roughly 40,000 residents. It is part of a quad-city metropolitan area perhaps best known for the Muscle Shoals Sound Studio that recorded the dulcet tones of many big-name music acts in the 1960s and 70s.

Image: Florenceal.org

On May 26, acting on a tip from Milwaukee, Wisc.-based cybersecurity firm Hold Security, KrebsOnSecurity contacted the office of Florence’s mayor to alert them that a Windows 10 system in their IT environment had been commandeered by a ransomware gang.

Comparing the information shared by Hold Security dark web specialist Yuliana Bellini with the employee directory on the Florence website indicated the username for the computer that attackers had used to gain a foothold in the network on May 6 belonged to the city’s manager of information systems.

My call was transferred to no fewer than three different people, none of whom seemed eager to act on the information. Eventually, I was routed to the non-emergency line for the Florence police department. When that call went straight to voicemail, I left a message and called the city’s emergency response team.

That last effort prompted a gracious return call the following day from a system administrator for the city, who thanked me for the heads up and said he and his colleagues had isolated the computer and Windows network account Hold Security flagged as hacked.

“I can’t tell you how grateful we are that you helped us dodge this bullet,” the technician said in a voicemail message for this author. “We got everything taken care of now, and some different protocols are in place. Hopefully we won’t have another near scare like we did, and hopefully we won’t have to talk to each other again.”

But on Friday, Florence Mayor Steve Holt confirmed that a cyberattack had shut down the city’s email system. Holt told local news outlets at the time there wasn’t any indication that ransomware was involved.

However, in an interview with KrebsOnSecurity Tuesday, Holt acknowledged the city was being extorted by DoppelPaymer, a ransomware gang with a reputation for negotiating some of the highest extortion payments across dozens of known ransomware families.

The average ransomware payment by ransomware strain. Source: Chainalysis.

Holt said the same gang appears to have simultaneously compromised networks belonging to four other victims within an hour of Florence, including another municipality that he declined to name. Holt said the extortionists initially demanded 39 bitcoin (~USD $378,000), but that an outside security firm hired by the city had negotiated the price down to 30 bitcoin (~USD $291,000).

Like many other cybercrime gangs operating these days, DoppelPaymer will steal reams of data from victims prior to launching the ransomware, and then threaten to publish or sell the data unless a ransom demand is paid.

Holt told KrebsOnSecurity the city can’t afford to see its citizens’ personal and financial data jeopardized by not paying.

“Do they have our stuff? We don’t know, but that’s the roll of the dice,” Holt said. Continue reading →


19
May 20

Ukraine Nabs Suspect in 773M Password ‘Megabreach’

In January 2019, dozens of media outlets raised the alarm about a new “megabreach” involving the release of some 773 million stolen usernames and passwords that was breathlessly labeled “the largest collection of stolen data in history.” A subsequent review by KrebsOnSecurity quickly determined the data was years old and merely a compilation of credentials pilfered from mostly public data breaches. Earlier today, authorities in Ukraine said they’d apprehended a suspect in the case.

The Security Service of Ukraine (SBU) on Tuesday announced the detention of a hacker known as Sanix (a.k.a. “Sanixer“) from the Ivano-Frankivsk region of the country. The SBU said they found on Sanix’s computer records showing he sold databases with “logins and passwords to e-mail boxes, PIN codes for bank cards, e-wallets of cryptocurrencies, PayPal accounts, and information about computers hacked for further use in botnets and for organizing distributed denial-of-service (DDoS) attacks.”

Items SBU authorities seized after raiding Sanix’s residence. Image: SBU.

Sanix became famous last year for posting to hacker forums that he was selling the 87GB password dump, labeled “Collection #1.” Shortly after his sale was first detailed by Troy Hunt, who operates the HaveIBeenPwned breach notification service, KrebsOnSecurity contacted Sanix to find out what all the fuss was about. From that story:

“Sanixer said Collection#1 consists of data pulled from a huge number of hacked sites, and was not exactly his ‘freshest’ offering. Rather, he sort of steered me away from that archive, suggesting that — unlike most of his other wares — Collection #1 was at least 2-3 years old. His other password packages, which he said are not all pictured in the above screen shot and total more than 4 terabytes in size, are less than a year old, Sanixer explained.”

Alex Holden, chief technology officer and founder of Milwaukee-based Hold Security, said Sanixer’s claim to infamy was simply for disclosing the Collection #1 data, which was just one of many credential dumps amalgamated by other cyber criminals.

“Today, it is even a more common occurrence to see mixing new and old breached credentials,” Holden said. “In fact, large aggregations of stolen credentials have been around since 2013-2014. Even the original attempt to sell the Yahoo breach data was a large mix of several previous unrelated breaches. Collection #1 was one of many credentials collections output by various cyber criminals gangs.” Continue reading →


30
Apr 20

How Cybercriminals are Weathering COVID-19

In many ways, the COVID-19 pandemic has been a boon to cybercriminals: With unprecedented numbers of people working from home and anxious for news about the virus outbreak, it’s hard to imagine a more target-rich environment for phishers, scammers and malware purveyors. In addition, many crooks are finding the outbreak has helped them better market their cybercriminal wares and services. But it’s not all good news: The Coronavirus also has driven up costs and disrupted key supply lines for many cybercriminals. Here’s a look at how they’re adjusting to these new realities.

FUELED BY MULES

One of the more common and perennial cybercriminal schemes is “reshipping fraud,” wherein crooks buy pricey consumer goods online using stolen credit card data and then enlist others to help them collect or resell the merchandise.

Most online retailers years ago stopped shipping to regions of the world most frequently associated with credit card fraud, including Eastern Europe, North Africa, and Russia. These restrictions have created a burgeoning underground market for reshipping scams, which rely on willing or unwitting residents in the United States and Europe — derisively referred to as “reshipping mules” — to receive and relay high-dollar stolen goods to crooks living in the embargoed areas.

A screen shot from a user account at “Snowden,” a long-running reshipping mule service.

But apparently a number of criminal reshipping services are reporting difficulties due to the increased wait time when calling FedEx or UPS (to divert carded goods that merchants end up shipping to the cardholder’s address instead of to the mule’s). In response, these operations are raising their prices and warning of longer shipping times, which in turn could hamper the activities of other actors who depend on those services.

That’s according to Intel 471, a cyber intelligence company that closely monitors hundreds of online crime forums. In a report published today, the company said since late March 2020 it has observed several crooks complaining about COVID-19 interfering with the daily activities of their various money mules (people hired to help launder the proceeds of cybercrime).

“One Russian-speaking actor running a fraud network complained about their subordinates (“money mules”) in Italy, Spain and other countries being unable to withdraw funds, since they currently were afraid to leave their homes,” Intel 471 observed. “Also some actors have reported that banks’ customer-support lines are being overloaded, making it difficult for fraudsters to call them for social-engineering activities (such as changing account ownership, raising withdrawal limits, etc).”

Still, every dark cloud has a silver lining: Intel 471 noted many cybercriminals appear optimistic that the impending global economic recession (and resultant unemployment) “will make it easier to recruit low-level accomplices such as money mules.”

Alex Holden, founder and CTO of Hold Security, agreed. He said while the Coronavirus has forced reshipping operators to make painful shifts in several parts of their business, the overall market for available mules has never looked brighter.

“Reshipping is way up right now, but there are some complications,” he said.

For example, reshipping scams have over the years become easier for both reshipping mule operators and the mules themselves. Many reshipping mules are understandably concerned about receiving stolen goods at their home and risking a visit from the local police. But increasingly, mules have been instructed to retrieve carded items from third-party locations.

“The mules don’t have to receive stolen goods directly at home anymore,” Holden said. “They can pick them up at Walgreens, Hotel lobbies, etc. There are a ton of reshipment tricks out there.”

But many of those tricks got broken with the emergence of COVID-19 and social distancing norms. In response, more mule recruiters are asking their hires to do things like reselling goods shipped to their homes on platforms like eBay and Amazon.

“Reshipping definitely has become more complicated,” Holden said. “Not every mule will run 10 times a day to the post office, and some will let the goods sit by the mailbox for days. But on the whole, mules are more compliant these days.”

GIVE AND TAKE

KrebsOnSecurity recently came to a similar conclusion: Last month’s story, “Coronavirus Widens the Money Mule Pool,” looked at one money mule operation that had ensnared dozens of mules with phony job offers in a very short period of time. Incidentally, the fake charity behind that scheme — which promised to raise money for Coronavirus victims — has since closed up shop and apparently re-branded itself as the Tessaris Foundation.

Charitable cybercriminal endeavors were the subject of a report released this week by cyber intel firm Digital Shadows, which looked at various ways computer crooks are promoting themselves and their hacking services using COVID-19 themed discounts and giveaways.

Like many commercials on television these days, such offers obliquely or directly reference the economic hardships wrought by the virus outbreak as a way of connecting on an emotional level with potential customers.

“The illusion of philanthropy recedes further when you consider the benefits to the threat actors giving away goods and services,” the report notes. “These donors receive a massive boost to their reputation on the forum. In the future, they may be perceived as individuals willing to contribute to forum life, and the giveaways help establish a track record of credibility.”

Brian’s Club — one of the underground’s largest bazaars for selling stolen credit card data and one that has misappropriated this author’s likeness and name in its advertising — recently began offering “pandemic support” in the form of discounts for its most loyal customers.

Continue reading →


17
Mar 20

Coronavirus Widens the Money Mule Pool

With many people being laid off or working from home thanks to the Coronavirus pandemic, cybercrooks are almost certain to have more than their usual share of recruitable “money mules” — people who get roped into money laundering schemes under the pretense of a work-at-home job offer. Here’s the story of one upstart mule factory that spoofs a major nonprofit and tells new employees they’ll be collecting and transmitting donations for an international “Coronavirus Relief Fund.”

On the surface, the Web site for the Vasty Health Care Foundation certainly looks legitimate. It includes various sections on funding relief efforts around the globe, explaining that it “connects nonprofits, donors, and companies in nearly every country around the world.” The site says it’s a nonprofit with offices based in Nebraska and Quebec, Canada.

Vasty is a phony charity that pretends to raise money for Coronavirus victims but instead hires people to help launder stolen funds. This and the rest of the content at Vasty’s site was lifted from GlobalGiving, a legitimate charity that is helping people affected by the pandemic.

The “Vasty Health Care Foundation” is one of several fraudulent Web sites that recruit money mules in the name of helping Coronavirus victims. The content on Vasty’s site was lifted almost entirely from globalgiving.org, a legitimate charity that actually is trying to help people affected by the pandemic.

“We have been contacted by job seekers asking if we are related to some of these job opportunities they’ve been finding on Indeed.com and Monster.com,” said Kevin Conroy, chief product officer at GlobalGiving. “And we always tell them no that’s not from us, and not to cash any checks someone may be giving them in relation to those offers.”

The Vasty domain — vastyhealthcarefoundation[.]com — was registered just weeks ago, although the site claims its organization has been around for years.

The crooks behind this scheme also seem to have submitted the Vasty name in custom links at vetting sites like The Better Business Bureau and Guidestar that ultimately take one to a summary of data on GlobalGiving. No doubt this is part of an effort to lend legitimacy to the Vasty name (hovering over the links above reveals the trickery).

What proof is there that Vasty isn’t a legitimate charity? None of the dozens of Canadian mules contacted by this author responded to requests for comment. But KrebsOnSecurity received copious amounts of information about this scam from Milwaukee, Wisc. based Hold Security, which managed to intercept key file exchanges between threat actors through public file sharing services.

Among those files were a set of form letters and boilerplate email messages that describe the ideal candidate for the job at Vasty and welcome new recruits to the Vasty payroll. Here’s a look at part of the job description, which includes (not pictured) a description of the healthcare plans and other benefits allegedly offered to Vasty employees.

After congratulating applicants (everyone who applies is “hired”) on their new positions, Vasty asks the recruits to do some busy work. In this case, new hires are sent to local pharmacies on some bogus errand, such as to inspect the pricing of face masks and hand sanitizer products for price-gouging.

“Now we have the first task for you. You will have to perform a trip within your city. So that we can compensate for transportation costs along with your hourly rate, I ask you to keep receipts confirming your expenses.

LOCATION: Sam’s Geneva Street Pharmacy

ADDRESS:  284 Geneva St, St. Catharines, ON L2N 2E8

I ask you to go to the pharmacy at the specified address. We are increasingly receiving reports of private sellers violating the pricing policy for products such as: aspirin, face masks are loose surgical masks with elastic loops that go around the ears, hand sanitizers.”

New recruits are then asked to assemble and submit a written report of their observations at the store in question.

These types of menial, meaningless tasks are a typical tactic of money mule recruitment schemes and they serve two main purposes: They separate out slackers from people who really need and want a job, and they help the employee feel like he’s doing something useful and legitimate (aside from just moving money around, which if brought up too soon might make him question whether the job is legit). Continue reading →


26
Feb 20

Zyxel 0day Affects its Firewall Products, Too

On Monday, networking hardware maker Zyxel released security updates to plug a critical security hole in its network attached storage (NAS) devices that is being actively exploited by crooks who specialize in deploying ransomware. Today, Zyxel acknowledged the same flaw is present in many of its firewall products.

This week’s story on the Zyxel patch was prompted by the discovery that exploit code for attacking the flaw was being sold in the cybercrime underground for $20,000. Alex Holden, the security expert who first spotted the code for sale, said at the time the vulnerability was so “stupid” and easy to exploit that he wouldn’t be surprised to find other Zyxel products were similarly affected.

Now it appears Holden’s hunch was dead-on.

“We’ve now completed the investigation of all Zyxel products and found that firewall products running specific firmware versions are also vulnerable,” Zyxel wrote in an email to KrebsOnSecurity. “Hotfixes have been released immediately, and the standard firmware patches will be released in March.”

The updated security advisory from Zyxel states the exploit works against its UTM, ATP, and VPN firewalls running firmware version ZLD V4.35 Patch 0 through ZLD V4.35 Patch 2, and that those with firmware versions before ZLD V4.35 Patch 0 are not affected.

Zyxel’s new advisory suggests that some affected firewall product won’t be getting hotfixes or patches for this flaw, noting that the affected products listed in the advisory are only those which are “within their warranty support period.”

Indeed, while the exploit also works against more than a dozen of Zyxel’s NAS product lines, the company only released updates for NAS products that were newer than 2016. Its advice for those still using those unsupported NAS devices? “Do not leave the product directly exposed to the internet. If possible, connect it to a security router or firewall for additional protection.”

Hopefully, your vulnerable, unsupported Zyxel NAS isn’t being protected by a vulnerable, unsupported Zyxel firewall product.

CERT’s advisory on the flaw rate this vulnerability at a “10” — its most severe. My advice? If you can’t patch it, pitch it. The zero-day sales thread first flagged by Holden also hinted at the presence of post-authentication exploits in many Zyxel products, but the company did not address those claims in its security advisories.

Recent activity suggests that attackers known for deploying ransomware have been actively working to test the zero-day for use against targets. Holden said the exploit is now being used by a group of bad guys who are seeking to fold the exploit into Emotet, a powerful malware tool typically disseminated via spam that is frequently used to seed a target with malcode which holds the victim’s files for ransom.

“To me, a 0day exploit in Zyxel is not as scary as who bought it,” he said. “The Emotet guys have been historically targeting PCs, laptops and servers, but their venture now into IoT devices is very disturbing.”


24
Feb 20

Zyxel Fixes 0day in Network Storage Devices

Patch comes amid active exploitation by ransomware gangs

Networking hardware vendor Zyxel today released an update to fix a critical flaw in many of its network attached storage (NAS) devices that can be used to remotely commandeer them. The patch comes 12 days after KrebsOnSecurity alerted the company that precise instructions for exploiting the vulnerability were being sold for $20,000 in the cybercrime underground.

Based in Taiwan, Zyxel Communications Corp. (a.k.a “ZyXEL”) is a maker of networking devices, including Wi-Fi routers, NAS products and hardware firewalls. The company has roughly 1,500 employees and boasts some 100 million devices deployed worldwide. While in many respects the class of vulnerability addressed in this story is depressingly common among Internet of Things (IoT) devices, the flaw is notable because it has attracted the interest of groups specializing in deploying ransomware at scale.

KrebsOnSecurity first learned about the flaw on Feb. 12 from Alex Holden, founder of Milwaukee-based security firm Hold Security. Holden had obtained a copy of the exploit code, which allows an attacker to remotely compromise more than a dozen types of Zyxel NAS products remotely without any help from users.

A snippet from the documentation provided by 500mhz for the Zyxel 0day.

Holden said the seller of the exploit code — a ne’er-do-well who goes by the nickname “500mhz” –is known for being reliable and thorough in his sales of 0day exploits (a.k.a. “zero-days,” these are vulnerabilities in hardware or software products that vendors first learn about when exploit code and/or active exploitation shows up online).

For example, this and previous zero-days for sale by 500mhz came with exhaustive documentation detailing virtually everything about the flaw, including any preconditions needed to exploit it, step-by-step configuration instructions, tips on how to remove traces of exploitation, and example search links that could be used to readily locate thousands of vulnerable devices.

500mhz’s profile on one cybercrime forum states that he is constantly buying, selling and trading various 0day vulnerabilities.

“In some cases, it is possible to exchange your 0day with my existing 0day, or sell mine,” his Russian-language profile reads.

The profile page of 500mhz, translated from Russian to English via Google Chrome.

PARTIAL PATCH

KrebsOnSecurity first contacted Zyxel on Feb. 12, sharing a copy of the exploit code and description of the vulnerability. When four days elapsed without any response from the vendor to notifications sent via multiple methods, this author shared the same information with vulnerability analysts at the U.S. Department of Homeland Security (DHS) and with the CERT Coordination Center (CERT/CC), a partnership between DHS and Carnegie Mellon University.

Less than 24 hours after contacting DHS and CERT/CC, KrebsOnSecurity heard back from Zyxel, which thanked KrebsOnSecurity for the alert without acknowledging its failure to respond until they were sent the same information by others.

“Thanks for flagging,” Zyxel’s team wrote on Feb. 17. “We’ve just received an alert of the same vulnerabilities from US-CERT over the weekend, and we’re now in the process of investigating. Still, we heartily appreciate you bringing it to our attention.”

Earlier today, Zyxel sent a message saying it had published a security advisory and patch for the zero-day exploit in some of its affected products. The vulnerable devices include NAS542, NAS540, NAS520, NAS326, NSA325 v2, NSA325, NSA320S, NSA320, NSA310S, NSA310, NSA221, NSA220+, NSA220, and NSA210. The flaw is designated as CVE-2020-9054.

However, many of these devices are no longer supported by Zyxel and will not be patched. Zyxel’s advice for those users is simply “do not leave the product directly exposed to the internet.”

“If possible, connect it to a security router or firewall for additional protection,” the advisory reads.

Holden said given the simplicity of the exploit — which allows an attacker to seize remote control over an affected device by injecting just two characters to the username field of the login panel for Zyxel NAS devices — it’s likely other Zyxel products may have related vulnerabilities.

“Considering how stupid this exploit is, I’m guessing this is not the only one of its class in their products,” he said.

CERT’s advisory on the flaw rates it at a “10” — its most severe. The advisory includes additional mitigation instructions, including a proof-of-concept exploit that has the ability to power down affected Zyxel devices.

Continue reading →


6
Jan 20

The Hidden Cost of Ransomware: Wholesale Password Theft

Organizations in the throes of cleaning up after a ransomware outbreak typically will change passwords for all user accounts that have access to any email systems, servers and desktop workstations within their network. But all too often, ransomware victims fail to grasp that the crooks behind these attacks can and frequently do siphon every single password stored on each infected endpoint. The result of this oversight may offer attackers a way back into the affected organization, access to financial and healthcare accounts, or — worse yet — key tools for attacking the victim’s various business partners and clients.

In mid-November 2019, Wisconsin-based Virtual Care Provider Inc. (VCPI) was hit by the Ryuk ransomware strain. VCPI manages the IT systems for some 110 clients that serve approximately 2,400 nursing homes in 45 U.S. states. VCPI declined to pay the multi-million dollar ransom demanded by their extortionists, and the attack cut off many of those elder care facilities from their patient records, email and telephone service for days or weeks while VCPI rebuilt its network.

Just hours after that story was published, VCPI chief executive and owner Karen Christianson reached out to say she hoped I would write a follow-up piece about how they recovered from the incident. My reply was that I’d consider doing so if there was something in their experience that I thought others could learn from their handling of the incident.

I had no inkling at the time of how much I would learn in the days ahead.

EERIE EMAILS

On December 3, I contacted Christianson to schedule a follow-up interview for the next day. On the morning of Dec. 4 (less than two hours before my scheduled call with VCPI and more than two weeks after the start of their ransomware attack) I heard via email from someone claiming to be part of the criminal group that launched the Ryuk ransomware inside VCPI.

That email was unsettling because its timing suggested that whoever sent it somehow knew I was going to speak with VCPI later that day. This person said they wanted me to reiterate a message they’d just sent to the owner of VCPI stating that their offer of a greatly reduced price for a digital key needed to unlock servers and workstations seized by the malware would expire soon if the company continued to ignore them.

“Maybe you chat to them lets see if that works,” the email suggested.

The anonymous individual behind that communication declined to provide proof that they were part of the group that held VPCI’s network for ransom, and after an increasingly combative and personally threatening exchange of messages soon stopped responding to requests for more information.

“We were bitten with releasing evidence before hence we have stopped this even in our ransoms,” the anonymous person wrote. “If you want proof we have hacked T-Systems as well. You may confirm this with them. We havent [sic] seen any Media articles on this and as such you should be the first to report it, we are sure they are just keeping it under wraps.” Security news site Bleeping Computer reported on the T-Systems Ryuk ransomware attack on Dec. 3.

In our Dec. 4 interview, VCPI’s acting chief information security officer — Mark Schafer, CISO at Wisconsin-based SVA Consulting — confirmed that the company received a nearly identical message that same morning, and that the wording seemed “very similar” to the original extortion demand the company received.

However, Schafer assured me that VCPI had indeed rebuilt its email network following the intrusion and strictly used a third-party service to discuss remediation efforts and other sensitive topics. Continue reading →