Business-to-business payments provider Billtrust is still recovering from a ransomware attack that began last week.  The company said it is in the final stages of bringing all of its systems back online from backups.

With more than 550 employees, Lawrence Township, N.J.-based Billtrust is a cloud-based service that lets customers view invoices, pay, or request bills via email or fax. In an email sent to customers today, Billtrust said it was consulting with law enforcement officials and with an outside security firm to determine the extent of the breach.

“Our standard security and back-up procedures have been and remain instrumental in our ability to execute the ongoing restoration of services,” the email reads. “Out of an abundance of caution, we cannot disclose the precise ransomware strains but will do so as soon as prudently possible.

In an interview with KrebsOnSecurity on Monday evening, Billtrust CEO Steven Pinado said the company became aware of a malware intrusion on Thursday, Oct. 17.

“We’re aware of the malware and have been able to stop the activity within our systems,” Pinado said. “We immediately started focusing on control, remediation and protection. The impact of that was several systems were no longer available to our customers. We’ve been fighting the fight, working on restoring services and also digging into the root cause.”

A report from BleepingComputer cites an unnamed source saying the ransomware strain that hit Billtrust was the BitPaymer ransomware, but that information could not be confirmed.

One of Billtrust’s customers has published a day-by-day chronology of the attack and communications from the company here (h/t @gossithedog).

Pinado said Billtrust had restored most of its systems, and that it was in the process now of putting additional security measures in place. He declined to discuss anything related to the ransomware attack, such as whether the company paid a ransom demand in exchange for a key to unlock files scrambled by the malware, although he allowed Billtrust does have cybersecurity insurance for just such occasions.

Billtrust recently teamed up with Visa to launch the Billtrust Business Payments Network, an effort to digitize payments between businesses.

Cloud service providers are a favorite target of attackers who deal in ransomware. In August, Wisconsin-based PerCSoft paid a hefty ransom to get out from beneath an attack that separated hundreds of dental offices from their patient records.

In July, attackers hit QuickBooks cloud hosting firm iNSYNQ, holding data hostage for many of the company’s clients. In February, cloud payroll data provider Apex Human Capital Management was knocked offline for three days following a ransomware infestation.

On Christmas Eve 2018, cloud hosting provider Dataresolution.net took its systems offline in response to a ransomware outbreak on its internal networks. The company was adamant that it would not pay the ransom demand, but it ended up taking several weeks for customers to fully regain access to their data.

Antivirus and security giant Avast and virtual private networking (VPN) software provider NordVPN each today disclosed months-long network intrusions that — while otherwise unrelated — shared a common cause: Forgotten or unknown user accounts that granted remote access to internal systems with little more than a password.

Based in the Czech Republic, Avast bills itself as the most popular antivirus vendor on the market, with over 435 million users. In a blog post today, Avast said it detected and addressed a breach lasting between May and October 2019 that appeared to target users of its CCleaner application, a popular Microsoft Windows cleanup and repair utility.

Avast said it took CCleaner downloads offline in September to check the integrity of the code and ensure it hadn’t been injected with malware. The company also said it invalidated the certificates used to sign previous versions of the software and pushed out a re-signed clean update of the product via automatic update on October 15. It then disabled and reset all internal user credentials.

“Having taken all these precautions, we are confident to say that our CCleaner users are protected and unaffected,” Avast’s Jaya Baloo wrote.

This is not the first so-called “supply chain” attack on Avast: In September 2018, researchers at Cisco Talos and Morphisec disclosed that hackers had compromised the computer cleanup tool for more than a month, leading to some 2.27 million downloads of the corrupt CCleaner version.

Avast said the intrusion began when attackers used stolen credentials for a VPN service that was configured to connect to its internal network, and that the attackers were not challenged with any sort of multi-factor authentication — such as a one-time code generated by a mobile app.

“We found that the internal network was successfully accessed with compromised credentials through a temporary VPN profile that had erroneously been kept enabled and did not require 2FA,” Baloo wrote.

THE NORDVPN BREACH

Separately, NordVPN, a virtual private networking services that promises to “protect your privacy online,” confirmed reports that it had been hacked. Today’s acknowledgment and blog post mortem from Nord comes just hours after it emerged that NordVPN had an expired internal private key exposed, potentially allowing anyone to spin out their own servers imitating NordVPN,” writes Zack Whittaker at TechCrunch.

VPN software creates an encrypted tunnel between your computer and the VPN provider, effectively blocking your ISP or anyone else on the network (aside from you and the VPN provider) from being able to tell which sites you are visiting or viewing the contents of your communications. This can offer a measure of anonymity, but the user also is placing a great deal of trust in that VPN service not to get hacked and expose this sensitive browsing data.

NordVPN’s account seems to downplay the intrusion, saying while the attackers could have used the private keys to intercept and view traffic for some of its customers’ traffic, the attackers would have been limited to eavesdropping on communications routing through just one of the company’s more than 3,000 servers.

“The server itself did not contain any user activity logs; none of our applications send user-created credentials for authentication, so usernames and passwords couldn’t have been intercepted either,” reads the NordVPN blog post. “On the same note, the only possible way to abuse the website traffic was by performing a personalized and complicated man-in-the-middle attack to intercept a single connection that tried to access NordVPN.”

NordVPN said the intrusion happened in March 2018 at one of its datacenters in Finland, noting that “the attacker gained access to the server by exploiting an insecure remote management system left by the datacenter provider while we were unaware that such a system existed.” NordVPN declined to name the datacenter provider, but said the provider removed the remote management account without notifying them on March 20, 2018.

“When we learned about the vulnerability the datacenter had a few months back, we immediately terminated the contract with the server provider and shredded all the servers we had been renting from them,” the company said. “We did not disclose the exploit immediately because we had to make sure that none of our infrastructure could be prone to similar issues. This couldn’t be done quickly due to the huge amount of servers and the complexity of our infrastructure.”

TechCrunch took NordVPN to task on the somewhat dismissive tone of its breach disclosure, noting that the company suffered a significant breach that went undetected for more than a year.

Kenneth White, director of the Open Crypto Audit Project, said on Twitter that based on the dumped Pastebin logs detailing the extent of the intrusion, “the attacker had full remote admin on their Finland node containers.”

“That’s God Mode folks,” White wrote. “And they didn’t log and didn’t detect it. I’d treat all their claims with great skepticism.”

ANALYSIS

Many readers are curious about whether they should enshroud all of their online communications by using a VPN. However, it’s important to understand the limitations of this technology, and to take the time to research providers before entrusting them with virtually all your browsing data — and possibly even compounding your privacy woes in the process. For a breakdown on what you should keep in mind when considering a VPN service, see this post.

Forgotten user accounts that provide remote access to internal systems — such as VPN and Remote Desktop services (RDP) — have been a persistent source of data breaches for years. Thousands of small to mid-sized brick-and-mortar businesses have been relieved of millions of customer payment card records over the years when their hacked IT contractors used the same remote access credentials at each client location.

Almost all of these breaches could have been stopped by requiring a second form of authentication in addition to a password, which can easily be stolen or phished.

The persistent supply chain attack against Avast brings to mind something I was considering the other day about the wisdom of allowing certain software to auto-update itself whenever it pleases. I’d heard from a reader who was lamenting the demise of programs like Secunia’s Personal Software Inspector and FileHippo, which allowed users to automatically download and install available updates for a broad range of third-party Windows programs.

These days, I find myself seeking out and turning off any auto-update functions in software that I install. I’d rather be alerted to new updates when I launch the program and have the ability to review what’s changing and whether anyone has experienced issues with the new version. I guess you could say years of dealing with unexpected surprises on Microsoft Patch Tuesdays has cured me of any sort of affinity I may have once had for auto-update features.

Cybercrime forums have been abuzz this week over news that BriansClub — one of the underground’s largest shops for stolen credit and debit cards — has been hacked, and its inventory of 26 million cards shared with security contacts in the banking industry. Now it appears this brazen heist may have been the result of one of BriansClub’s longtime competitors trying to knock out a rival.

Last month, KrebsOnSecurity was contacted by an anonymous source who said he had the full database of 26M cards stolen from BriansClub, a carding site that has long used this author’s name and likeness in its advertising. The stolen database included cards added to the site between mid-2015 and August 2019.

This was a major event in the underground, as experts estimate the total number of stolen cards leaked from BriansClub represent almost 30 percent of the cards on the black market today.

The purloined database revealed BriansClub sold roughly 9.1 million stolen credit cards, earning the site and its resellers a cool $126 million in sales over four years.

In response to questions from KrebsOnSecurity, the administrator of BriansClub acknowledged that the data center serving his site had been hacked earlier in the year (BriansClub claims this happened in February), but insisted that all of the cards stolen by the hacker had been removed from BriansClub store inventories.

However, as I noted in Tuesday’s story, multiple sources confirmed they were able to find plenty of card data included in the leaked database that was still being offered for sale at BriansClub.

Perhaps inevitably, the admin of BriansClub took to the cybercrime forums this week to defend his business and reputation, re-stating his claim that all cards included in the leaked dump had been cleared from store shelves.

Meanwhile, some of BriansClub’s competitors gloated about the break-in. According to the administrator of Verified, one of the longest running Russian language cybercrime forums, the hack of BriansClub was perpetrated by a fairly established ne’er-do-well who uses the nickname “MrGreen” and runs a competing card shop by the same name.

The Verified site admin said MrGreen had been banned from the forum, and added that “sending anything to Krebs is the lowest of all lows” among accomplished and self-respecting cybercriminals. I’ll take that as a compliment.

This would hardly be the first time some cybercriminal has used me to take down one of his rivals. In most cases, I’m less interested in the drama and more keen on validating the data and getting it into the proper hands to do some good.

That said, if the remainder of BriansClub’s competitors want to use me to take down the rest of the carding market, I’m totally fine with that.

“BriansClub,” one of the largest underground stores for buying stolen credit card data, has itself been hacked. The data stolen from BriansClub encompasses more than 26 million credit and debit card records taken from hacked online and brick-and-mortar retailers over the past four years, including almost eight million records uploaded to the shop in 2019 alone.

Last month, KrebsOnSecurity was contacted by a source who shared a plain text file containing what was claimed to be the full database of cards for sale both currently and historically through BriansClub[.]at, a thriving fraud bazaar named after this author. Imitating my site, likeness and namesake, BriansClub even dubiously claims a copyright with a reference at the bottom of each page: “© 2019 Crabs on Security.”

Multiple people who reviewed the database shared by my source confirmed that the same credit card records also could be found in a more redacted form simply by searching the BriansClub Web site with a valid, properly-funded account.

All of the card data stolen from BriansClub was shared with multiple sources who work closely with financial institutions to identify and monitor or reissue cards that show up for sale in the cybercrime underground.

The leaked data shows that in 2015, BriansClub added just 1.7 million card records for sale. But business would pick up in each of the years that followed: In 2016, BriansClub uploaded 2.89 million stolen cards; 2017 saw some 4.9 million cards added; 2018 brought in 9.2 million more.

Between January and August 2019 (when this database snapshot was apparently taken), BriansClub added roughly 7.6 million cards.

Most of what’s on offer at BriansClub are “dumps,” strings of ones and zeros that — when encoded onto anything with a magnetic stripe the size of a credit card — can be used by thieves to purchase electronics, gift cards and other high-priced items at big box stores.

As shown in the table below (taken from this story), many federal hacking prosecutions involving stolen credit cards will for sentencing purposes value each stolen card record at $500, which is intended to represent the average loss per compromised cardholder.

STOLEN BACK FAIR AND SQUARE

An extensive analysis of the database indicates BriansClub holds approximately $414 million worth of stolen credit cards for sale, based on the pricing tiers listed on the site. That’s according to an analysis by Flashpoint, a security intelligence firm based in New York City.

Allison Nixon, the company’s director of security research, said Flashpoint had help from numerous parties in crunching the numbers from the massive leaked database.

Nixon said the data suggests that between 2015 and August 2019, BriansClub sold roughly 9.1 million stolen credit cards, earning the site $126 million in sales (all sales are transacted in bitcoin).

If we take just the 9.1 million cards that were confirmed sold through BriansClub, we’re talking about $2.27 billion in likely losses at the $500 average loss per card figure from the Justice Department.

Also, it seems likely the total number of stolen credit cards for sale on BriansClub and related sites vastly exceeds the number of criminals who will buy such data. Shame on them for not investing more in marketing!

There’s no easy way to tell how many of the 26 million or so cards for sale at BriansClub are still valid, but the closest approximation of that — how many unsold cards have expiration dates in the future — indicates more than 14 million of them could still be valid.

The archive also reveals the proprietor(s) of BriansClub frequently uploaded new batches of stolen cards — some just a few thousand records, and others tens of thousands.

That’s because like many other carding sites, BriansClub mostly resells cards stolen by other cybercriminals — known as resellers or affiliates — who earn a percentage from each sale. It’s not yet clear how that revenue is shared in this case, but perhaps this information will be revealed in further analysis of the purloined database.

BRIANS CHAT

In a message titled “Your site is hacked,’ KrebsOnSecurity requested comment from BriansClub via the “Support Tickets” page on the carding shop’s site, informing its operators that all of their card data had been shared with the card-issuing banks.

I was surprised and delighted to receive a polite reply a few hours later from the site’s administrator (“admin”):

“No. I’m the real Brian Krebs here

Correct subject would be the data center was hacked.

Will get in touch with you on jabber. Should I mention that all information affected by the data-center breach has been since taken off sales, so no worries about the issuing banks.”

Flashpoint’s Nixon said a spot check comparison between the stolen card database and the card data advertised at BriansClub suggests the administrator is not being truthful in his claims of having removed the leaked stolen card data from his online shop.

The admin hasn’t yet responded to follow-up questions, such as why BriansClub chose to use my name and likeness to peddle millions of stolen credit cards.

Almost certainly, at least part of the appeal is that my surname means “crab” (or cancer), and crab is Russian hacker slang for “carder,” a person who engages in credit card fraud.

HACKING BACK?

Nixon said breaches of criminal website databases often lead not just to prevented cybercrimes, but also to arrests and prosecutions.

“When people talk about ‘hacking back,’ they’re talking about stuff like this,” Nixon said. “As long as our government is hacking into all these foreign government resources, they should be hacking into these carding sites as well. There’s a lot of attention being paid to this data now and people are remediating and working on it.”

By way of example on hacking back, she pointed to the 2016 breach of vDOS — at the time the largest and most powerful service for knocking Web sites offline in large-scale cyberattacks.

Soon after vDOS’s database was stolen and leaked to this author, its two main proprietors were arrested. Also, the database added to evidence of criminal activity for several other individuals who were persons of interest in unrelated cybercrime investigations, Nixon said.

“When vDOS got breached, that basically reopened cases that were cold because [the leak of the vDOS database] supplied the final piece of evidence needed,” she said.

THE TARGET BREACH OF THE UNDERGROUND?

After many hours spent poring over this data, it became clear I needed some perspective on the scope and impact of this breach. As a major event in the cybercrime underground, was it somehow the reverse analog of the Target breach — which negatively impacted tens of millions of consumers and greatly enriched a large number of bad guys? Or was it more prosaic, like a Jimmy Johns-sized debacle?

For that insight, I spoke with Gemini Advisory, a New York-based company that works with financial institutions to monitor dozens of underground markets trafficking in stolen card data.

Andrei Barysevich, co-founder and CEO at Gemini, said the breach at BriansClub is certainly significant, given that Gemini currently tracks a total of 87 million credit and debit card records for sale across the cybercrime underground.

Gemini is monitoring most underground stores that peddle stolen card data — including such heavy hitters as Joker’s Stash, Trump’s Dumps, and BriansDump.

Contrary to popular belief, when these shops sell a stolen credit card record, that record is then removed from the inventory of items for sale. This allows companies like Gemini to determine roughly how many new cards are put up for sale and how many have sold.

Barysevich said the loss of so many valid cards may well impact how other carding stores compete and price their products.

“With over 78% of the illicit trade of stolen cards attributed to only a dozen of dark web markets, a breach of this magnitude will undoubtedly disturb the underground trade in the short term,” he said. “However, since the demand for stolen credit cards is on the rise, other vendors will undoubtedly attempt to capitalize on the disappearance of the top player.”

Liked this story and want to learn more about how carding shops operate? Check out Peek Inside a Professional Carding Shop. Want to help this site continue to produce useful, impactful journalism? Consider donating!

On Tuesday Microsoft issued software updates to fix almost five dozen security problems in Windows and software designed to run on top of it. By most accounts, it’s a relatively light patch batch this month. Here’s a look at the highlights.

Happily, only about 15 percent of the bugs patched this week earned Microsoft’s most dire “critical” rating. Microsoft labels flaws critical when they could be exploited by miscreants or malware to seize control over a vulnerable system without any help from the user.

Also, Adobe has kindly granted us another month’s respite from patching security holes in its Flash Player browser plugin.

Included in this month’s roundup is something Microsoft actually first started shipping in the third week of September, when it released an emergency update to fix a critical Internet Explorer zero-day flaw (CVE-2019-1367) that was being exploited in the wild.

That out-of-band security update for IE caused printer errors for many Microsoft users whose computers applied the emergency update early on, according to Windows update expert Woody Leonhard. Apparently, the fix available through this month’s roundup addresses those issues.

Security firm Ivanti notes that the patch for the IE zero day flaw was released prior to today for Windows 10 through cumulative updates, but that an IE rollup for any pre-Windows 10 systems needs to be manually downloaded and installed.

Once again, Microsoft is fixing dangerous bugs in its Remote Desktop Client, the Windows feature that lets a user interact with a remote desktop as if they were sitting in front of the other PC. On the bright side, this critical bug can only be exploited by tricking a user into connecting to a malicious Remote Desktop server — not exactly the most likely attack scenario.

Other notable vulnerabilities addressed this month include a pair of critical security holes in Microsoft Excel versions 2010-2019 for Mac and Windows, as well as Office 365. These flaws would allow an attacker to install malware just by getting a user to open a booby-trapped Office file.

Windows 10 likes to install patches all in one go and reboot your computer on its own schedule. Microsoft doesn’t make it easy for Windows 10 users to change this setting, but it is possible. For all other Windows OS users, if you’d rather be alerted to new updates when they’re available so you can choose when to install them, there’s a setting for that in Windows Update. To get there, click the Windows key on your keyboard and type “windows update” into the box that pops up.

Staying up-to-date on Windows patches is good. Updating only after you’ve backed up your important data and files is even better. A reliable backup means you’re not pulling your hair out if the odd buggy patch causes problems booting the system. So do yourself a favor and backup your files before installing any patches.

As always, if you experience any problems installing any of the patches this month, please feel free to leave a comment about it below; there’s a decent chance other readers have experienced the same and may even chime in here with some helpful tips.