If you operate a cybercrime business that relies on disseminating malicious software, you probably also spend a good deal of time trying to disguise or “crypt” your malware so that it appears benign to antivirus and security products. In fact, the process of “crypting” malware is sufficiently complex and time-consuming that most serious cybercrooks will outsource this critical function to a handful of trusted third parties. This story explores the history and identity behind Cryptor[.]biz, a long-running crypting service that is trusted by some of the biggest names in cybercrime.

Virtually all malware that is deployed for use in data stealing at some point needs to be crypted. This highly technical, laborious process involves iteratively altering the appearance and behavior of a malicious file until it no longer sets off alarm bells when scanned by different antivirus tools.

Experienced malware purveyors understand that if they’re not continuously crypting their malware before sending it out, then a lot more of whatever digital disease they are trying to spread is going to get flagged by security tools. In short, if you are running a cybercrime enterprise and you’re not equipped to handle this crypting process yourself, you probably need to pay someone else to do it for you.

Thanks to the high demand for reliable crypting services, there are countless cybercriminals who’ve hung out their shingles as crypting service providers. However, most of these people do not appear to be very good at what they do, because most are soon out of business.

One standout is Cryptor[.]biz. This service is actually recommended by the purveyors of the RedLine information stealer malware, which is a popular and powerful malware kit that specializes in stealing victim data and is often used to lay the groundwork for ransomware attacks. Cryptor[.]biz also has been recommended to customers of the Predator information stealer malware family (via the malware’s Telegram support channels).

WHO RUNS CRYPTOR[.]BIZ?

As good as Cryptor[.]biz may be at obfuscating malware, its proprietor does not appear to have done a great job covering his own tracks. The registration records for the website Cryptor[.]biz are hidden behind privacy protection services, but the site’s homepage says potential customers should register by visiting the domain crypt[.]guru, or by sending a Jabber instant message to the address “masscrypt@exploit.im.”

Crypt[.]guru’s registration records also are hidden, yet passive domain name system (DNS) records for both cryptor[.]biz and crypt[.]guru show that in 2018 the domains were forwarding incoming email to the address obelisk57@gmail.com.

Cyber intelligence firm Intel 471 reports that obelisk57@gmail.com was used to register an account on the forum Blacksoftware under the nickname “Kerens.” Meanwhile, the Jabber address masscrypt@exploit.im has been associated with the user Kerens on the Russian hacking forum Exploit from 2011 to the present day.

The very first post by Kerens on Exploit in 2011 was a negative review of a popular crypting service that predated Cryptor[.]biz called VIP Crypt, which Kerens accused of being “shitty” and unreliable. But Intel 471 finds that after his critical review of VIP Crypt, Kerens did not post publicly on Exploit again for another four years until October 2016, when they suddenly began advertising Cryptor[.]biz.

Intel 471 found that Kerens used the email address pepyak@gmail.com, which also was used to register Kerens accounts on the Russian language hacking forums Verified and Damagelab.

Ironically, Verified has itself been hacked multiple times over the years, with its private messages and user registration details leaked online. Those records indicate the user Kerens registered on Verified in March 2009 from an Internet address in Novosibirsk, a city in the southern Siberian region of Russia.

In 2010, someone with the username Pepyak on the Russian language affiliate forum GoFuckBiz[.]com shared that they typically split their time during the year between living in Siberia (during the milder months) and Thailand (when Novosibirsk is typically -15 °C/°5F).

For example, in one conversation about the best car to buy for navigating shoddy roads, Pepyak declared, “We have shitty roads in Siberia.” In January 2010, Pepyak asked the GoFuckBiz community where one might find a good USB-based modem in Phuket, Thailand.

DomainTools.com says the email address pepyak@gmail.com was used to register 28 domain names over the years, including a now-defunct Russian automobile sales website called “autodoska[.]biz.” DomainTools shows this website was registered in 2008 to a Yuri Churnov from Sevastpol, Crimea (prior to Russia’s annexation of Crimea in 2014, the peninsula was part of Ukraine).

The WHOIS records for autodoska[.]biz were changed in 2010 to Sergey Purtov (pepyak@gmail.com) from Yurga, a town in Russia’s Kemerovo Oblast, which is a relatively populous area in Western Siberia that is adjacent to Novosibirsk.

Many of the 28 domains registered to pepyak@gmail.com have another email address in their registration records: unforgiven57@mail.ru. According to DomainTools, the Unforgiven email address was used to register roughly a dozen domains, including three that were originally registered to Keren’s email address — pepyak@gmail.com (e.g., antivirusxp09[.]com).

One of the domains registered in 2006 to the address unforgiven57@mail.ru was thelib[.]ru, which for many years was a place to download pirated e-books. DomainTools says thelib[.]ru was originally registered to a Sergey U Purtov.

Most of the two-dozen domains registered to pepyak@gmail.com shared a server at one point with a small number of other domains, including mobile-soft[.]su, which was registered to the email address spurtov@gmail.com.

CDEK, an express delivery company based in Novosibirsk, was apparently hacked at some point because cyber intelligence firm Constella Intelligence found that its database shows the email address spurtov@gmail.com was assigned to a Sergey Yurievich Purtov (Сергей Юрьевич Пуртов).

DomainTools says the same phone number in the registration records for autodoska[.]biz (+7.9235059268) was used to secure two other domains — bile[.]ru and thelibrary[.]ru, both of which were registered to a Sergey Y Purtov.

A search on the phone number 79235059268 in Skype reveals these digits belong to a “Sergey” from Novosibirsk with the now-familiar username  — Pepyak.

Bringing things full circle, Constella Intelligence shows that various online accounts tied to the email address unforgiven57@mail.ru frequently relied on the somewhat unique password, “plk139t51z.” Constella says that same password was used for just a handful of other email addresses, including gumboldt@gmail.com.

Hacked customer records from CDEK show gumboldt@gmail.com was tied to a customer named Sergey Yurievich Purtov. DomainTools found that virtually all of the 15 domain names registered to gumboldt@gmail.com (including the aforementioned mobile-soft[.]su) were at one point registered to spurtov@gmail.com.

Intel 471 reports that gumboldt@gmail.com was used in 2009 to register a user by the nickname “Kolumb” on the Russian hacking forum Antichat. From Kolumb’s posts on Antichat, it seems this user was mostly interested in buying access to compromised computers inside of Russia.

Then in December 2009, Kolumb said they were in desperate need of a reliable crypting service or full-time cryptor.

“We need a person who will crypt software every day, sometimes even a couple of times a day,” Kolumb wrote on Antichat.

Mr. Purtov did not respond to requests for comment sent to any of the email addresses referenced in this report. Mail.ru responded that the email address spurtov@mail.ru is no longer active.

ANALYSIS

As KrebsOnSecurity opined on Mastodon earlier this week, it makes a lot of sense for cybersecurity researchers and law enforcement alike to focus attention on the top players in the crypting space — for several reasons. Most critically, the cybercriminals offering time-tested crypting services also tend to be among the most experienced and connected malicious coders on the planet.

Think of it this way: By definition, a crypting service scans and examines all types of malware before those new nasties are first set loose in the wild. This fact alone should make these criminal enterprises a primary target of cybersecurity firms looking to gain more timely intelligence about new malware.

Also, a review of countless posts and private messages from Pepyak and other crypting providers shows that a successful crypting service will have direct and frequent contact with some of the world’s most advanced malware authors.

In short, infiltrating or disrupting a trusted crypting service can be an excellent way to slow down or even sideline a large number of cybercrime operations all at once.

Further reading on the crypting industry:

This Service Helps Malware Authors Fix Flaws in Their Code
Antivirus is Dead: Long Live Antivirus!

The U.S. government agency in charge of improving the nation’s cybersecurity posture is ordering all federal agencies to take new measures to restrict access to Internet-exposed networking equipment. The directive comes amid a surge in attacks targeting previously unknown vulnerabilities in widely used security and networking appliances.

Under a new order from the Cybersecurity and Infrastructure Security Agency (CISA), federal agencies will have 14 days to respond to any reports from CISA about misconfigured or Internet-exposed networking equipment. The directive applies to any networking devices — such as firewalls, routers and load balancers — that allow remote authentication or administration.

The order requires federal departments to limit access so that only authorized users on an agency’s local or internal network can reach the management interfaces of these devices. CISA’s mandate follows a slew of recent attacks wherein attackers exploited zero-day flaws in popular networking products to conduct ransomware and cyber espionage attacks on victim organizations.

Earlier today, incident response firm Mandiant revealed that since at least October 2022, Chinese cyber spies have been exploiting a zero-day vulnerability in many email security gateway (ESG) appliances sold by California-based Barracuda Networks to hoover up email from organizations using these devices.

Barracuda was alerted to the exploitation of a zero-day in its products in mid-May, and two days later the company pushed a security update to address the flaw in all affected devices. But last week, Barracuda took the highly unusual step of offering to replace compromised ESGs, evidently in response to malware that altered the systems in such a fundamental way that they could no longer be secured remotely with software updates.

According to Mandiant, a previously unidentified Chinese hacking group was responsible for exploiting the Barracuda flaw, and appeared to be searching through victim organization email records for accounts “belonging to individuals working for a government with political or strategic interest to [China] while this victim government was participating in high-level, diplomatic meetings with other countries.”

When security experts began raising the alarm about a possible zero-day in Barracuda’s products, the Chinese hacking group altered their tactics, techniques and procedures (TTPs) in response to Barracuda’s efforts to contain and remediate the incident, Mandiant found.

Mandiant said the attackers will continue to change their tactics and malware, “especially as network defenders continue to take action against this adversary and their activity is further exposed by the infosec community.”

Meanwhile, this week we learned more details about the ongoing exploitation of a zero-day flaw in a broad range of virtual private networking (VPN) products made by Fortinet — devices many organizations rely on to facilitate remote network access for employees.

On June 11, Fortinet released a half-dozen security updates for its FortiOS firmware, including a weakness that researchers said allows an attacker to run malware on virtually any Fortinet SSL VPN appliance. The researchers found that just being able to reach the management interface for a vulnerable Fortinet SSL VPN appliance was enough to completely compromise the devices.

“This is reachable pre-authentication, on every SSL VPN appliance,” French vulnerability researcher Charles Fol tweeted. “Patch your #Fortigate.”

In details published on June 12, Fortinet confirmed that one of the vulnerabilities (CVE-2023-27997) is being actively exploited. The company said it discovered the weakness in an internal code audit that began in January 2023 — when it learned that Chinese hackers were exploiting a different zero-day flaw in its products.

Shodan.io, the search engine made for finding Internet of Things devices, reports that there are currently more than a half-million vulnerable Fortinet devices reachable via the public Internet.

The new cybersecurity directive from CISA orders agencies to remove any networking device management interfaces from the internet by making them only accessible from an internal enterprise network (CISA recommends an isolated management network). CISA also says agencies should “deploy capabilities, as part of a Zero Trust Architecture, that enforce access control to the interface through a policy enforcement point separate from the interface itself (preferred action).”

Security experts say CISA’s directive highlights the reality that cyberspies and ransomware gangs are making it increasingly risky for organizations to expose any devices to the public Internet, because these groups have strong incentives to probe such devices for previously unknown security vulnerabilities.

The most glaring example of this dynamic can be seen in the frequency with which ransomware groups have discovered and pounced on zero-day flaws in widely-used file-transfer protocol (FTP) applications. One ransomware gang in particular — Cl0p — has repeatedly exploited zero day bugs in various FTP appliances to extort tens of millions of dollars from hundreds of ransomware victims.

On February 2, KrebsOnSecurity broke the news that attackers were exploiting a zero-day vulnerability in the GoAnywhere FTP appliance by Fortra. By the time security updates were available to fix the vulnerability, Cl0p had already used it to steal data from more than a hundred organizations running Fortra’s FTP appliance.

According to CISA, on May 27, Cl0p began exploiting a previously unknown flaw in MOVEit Transfer, a popular Internet-facing file transfer application. MOVEit parent Progress Software has since released security updates to address the weakness, but Cl0p claims to have already used it to compromise hundreds of victim organizations. TechCrunch has been tracking the fallout from victim organizations, which range from banks and insurance providers to universities and healthcare entities.

The always on-point weekly security news podcast Risky Business has recently been urging organizations to jettison any and all FTP appliances, noting that Cl0p (or another crime gang) is likely to visit the same treatment on other FTP appliance vendors.

But that sound advice doesn’t exactly scale for mid-tier networking devices like Barracuda ESGs or Fortinet SSL VPNs, which are particularly prominent in small to mid-sized organizations.

“It’s not like FTP services, you can’t tell an enterprise [to] turn off the VPN [because] the productivity hit of disconnecting the VPN is terminal, it’s a non-starter,” Risky Business co-host Adam Boileau said on this week’s show. “So how to mitigate the impact of having to use a domain-joined network appliance at the edge of your network that is going to get zero-day in it? There’s no good answer.”

Risky Business founder Patrick Gray said the COVID-19 pandemic breathed new life into entire classes of networking appliances that rely on code which was never designed with today’s threat models in mind.

“In the years leading up to the pandemic, the push towards identity-aware proxies and zero trust everything and moving away from this type of equipment was gradual, but it was happening,” Gray said. “And then COVID-19 hit and everybody had to go work from home, and there really was one option to get going quickly — which was to deploy VPN concentrators with enterprise features.”

Gray said the security industry had been focused on building the next generation of remote access tools that are more security-hardened, but when the pandemic hit organizations scrambled to cobble together whatever they could.

“The only stuff available in the market was all this old crap that is not QA’d properly, and every time you shake them CVEs fall out,” Gray remarked, calling the pandemic, “a shot in the arm” to companies like Fortinet and Barracuda.

“They sold so many VPNs through the pandemic and this is the hangover,” Gray said. “COVID-19 extended the life of these companies and technologies, and that’s unfortunate.”

Microsoft Corp. today released software updates to fix dozens of security vulnerabilities in its Windows operating systems and other software. This month’s relatively light patch load has another added bonus for system administrators everywhere: It appears to be the first Patch Tuesday since March 2022 that isn’t marred by the active exploitation of a zero-day vulnerability in Microsoft’s products.

June’s Patch Tuesday features updates to plug at least 70 security holes, and while none of these are reported by Microsoft as exploited in-the-wild yet, Redmond has flagged several in particular as “more likely to be exploited.”

Top of the list on that front is CVE-2023-29357, which is a “critical” bug in Microsoft SharePoint Server that can be exploited by an unauthenticated attacker on the same network. This SharePoint flaw earned a CVSS rating of 9.8 (10.0 is the most dangerous).

“An attacker able to gain admin access to an internal SharePoint server could do a lot of harm to an organization,” said Kevin Breen, director of cyber threat research at Immersive Labs. “Gaining access to sensitive and privileged documents, stealing and deleting documents as part of a ransomware attack or replacing real documents with malicious copies to further infect users in the organization.”

There are at least three other vulnerabilities fixed this month that earned a collective 9.8 CVSS score, and they all concern a widely-deployed component called the Windows Pragmatic General Multicast (PGM), which is used for delivering multicast data — such as video streaming or online gaming.

Security firm Action1 says all three bugs (CVE-2023-32015, CVE-2023-32014, and CVE-2023-29363) can be exploited over the network without requiring any privileges or user interaction, and affected systems include all versions of Windows Server 2008 and later, as well as Windows 10 and later.

It wouldn’t be a proper Patch Tuesday if we also didn’t also have scary security updates for organizations still using Microsoft Exchange for email. Breen said this month’s Exchange bugs (CVE-2023-32031 and CVE-2023-28310) closely mirror the vulnerabilities identified as part of ProxyNotShell exploits, where an authenticated user in the network could exploit a vulnerability in the Exchange to gain code execution on the server.

Breen said while Microsoft’s patch notes indicate that an attacker must already have gained access to a vulnerable host in the network, this is typically achieved through social engineering attacks with spear phishing to gain initial access to a host before searching for other internal targets.

“Just because your Exchange server doesn’t have internet-facing authentication doesn’t mean it’s protected,” Breen said, noting that Microsoft says the Exchange flaws are not difficult for attackers to exploit.

For a closer look at the patches released by Microsoft today and indexed by severity and other metrics, check out the always-useful Patch Tuesday roundup from the SANS Internet Storm Center. And it’s not a bad idea to hold off updating for a few days until Microsoft works out any kinks in the updates: AskWoody.com usually has the lowdown on any patches that may be causing problems for Windows users.

As always, please consider backing up your system or at least your important documents and data before applying system updates. And if you run into any problems with these updates, please drop a note about it here in the comments.

It’s not often that a zero-day vulnerability causes a network security vendor to urge customers to physically remove and decommission an entire line of affected hardware — as opposed to just applying software updates. But experts say that is exactly what transpired this week with Barracuda Networks, as the company struggled to combat a sprawling malware threat which appears to have undermined its email security appliances in such a fundamental way that they can no longer be safely updated with software fixes.

Campbell, Calif. based Barracuda said it hired incident response firm Mandiant on May 18 after receiving reports about unusual traffic originating from its Email Security Gateway (ESG) devices, which are designed to sit at the edge of an organization’s network and scan all incoming and outgoing email for malware.

On May 19, Barracuda identified that the malicious traffic was taking advantage of a previously unknown vulnerability in its ESG appliances, and on May 20 the company pushed a patch for the flaw to all affected appliances (CVE-2023-2868).

In its security advisory, Barracuda said the vulnerability existed in the Barracuda software component responsible for screening attachments for malware. More alarmingly, the company said it appears attackers first started exploiting the flaw in October 2022.

But on June 6, Barracuda suddenly began urging its ESG customers to wholesale rip out and replace — not patch — affected appliances.

“Impacted ESG appliances must be immediately replaced regardless of patch version level,” the company’s advisory warned. “Barracuda’s recommendation at this time is full replacement of the impacted ESG.”

Rapid7‘s Caitlin Condon called this remarkable turn of events “fairly stunning,” and said there appear to be roughly 11,000 vulnerable ESG devices still connected to the Internet worldwide.

“The pivot from patch to total replacement of affected devices is fairly stunning and implies the malware the threat actors deployed somehow achieves persistence at a low enough level that even wiping the device wouldn’t eradicate attacker access,” Condon wrote.

Barracuda said the malware was identified on a subset of appliances that allowed the attackers persistent backdoor access to the devices, and that evidence of data exfiltration was identified on some systems.

Rapid7 said it has seen no evidence that attackers are using the flaw to move laterally within victim networks. But that may be small consolation for Barracuda customers now coming to terms with the notion that foreign cyberspies probably have been hoovering up all their email for months.

Nicholas Weaver, a researcher at University of California, Berkeley’s International Computer Science Institute (ICSI), said it is likely that the malware was able to corrupt the underlying firmware that powers the ESG devices in some irreparable way.

“One of the goals of malware is to be hard to remove, and this suggests the malware compromised the firmware itself to make it really hard to remove and really stealthy,” Weaver said. “That’s not a ransomware actor, that’s a state actor. Why? Because a ransomware actor doesn’t care about that level of access. They don’t need it. If they’re going for data extortion, it’s more like a smash-and-grab. If they’re going for data ransoming, they’re encrypting the data itself — not the machines.”

In addition to replacing devices, Barracuda says ESG customers should also rotate any credentials connected to the appliance(s), and check for signs of compromise dating back to at least October 2022 using the network and endpoint indicators the company has released publicly.

One of the most expensive aspects of any cybercriminal operation is the time and effort it takes to constantly create large numbers of new throwaway email accounts. Now a new service offers to help dramatically cut costs associated with large-scale spam and account creation campaigns, by paying people to sell their email account credentials and letting customers temporarily rent access to a vast pool of established accounts at major providers.

The service in question — kopeechka[.]store — is perhaps best described as a kind of unidirectional email confirmation-as-a-service that promises to “save your time and money for successfully registering multiple accounts.”

“Are you working on large volumes and are costs constantly growing?” Kopeechka’s website asks. “Our service will solve all your problems.”

As a customer of this service, you don’t get full access to the email inboxes you are renting. Rather, you configure your botnet or spam machine to make an automated application programming interface (API) call to the Kopeechka service, which responds with a working email address at an email provider of your choosing.

Once you’ve entered the supplied email address into the new account registration page at some website or service, you tell Kopeechka which service or website you’re expecting an account confirmation link from, and they will then forward any new messages matching that description to your Kopeechka account panel.

Ensuring that customers cannot control inboxes rented through the service means that Kopeechka can rent the same email address to multiple customers (at least until that email address has been used to register accounts at most of the major online services).

Kopeechka also has multiple affiliate programs, including one that pays app developers for embedding Kopeechka’s API in their software. However, far more interesting is their program for rewarding people who choose to sell Kopeechka usernames and passwords for working email addresses.

Kopeechka means “penny” in Russian, which is generous verbiage (and coinage) for a service that charges a tiny fraction of a penny for access to account confirmation links. Their pricing fluctuates slightly based on which email provider you choose, but a form on the service’s homepage says a single confirmation message from apple.com to outlook.com costs .07 rubles, which is currently equal to about $0.00087 dollars.

“Emails can be uploaded to us for sale, and you will receive a percentage of purchases %,” the service explains. “You upload 1 mailbox of a certain domain, discuss percentage with our technical support (it depends on the liquidity of the domain and the number of downloaded emails).”

We don’t have to look very far for examples of Kopeechka in action. In May, KrebsOnSecurity interviewed a Russian spammer named “Quotpw“ who was mass-registering accounts on the social media network Mastodon in order to conduct a series of huge spam campaigns advertising scam cryptocurrency investment platforms.

Much of the fodder for that story came from Renaud Chaput, a freelance programmer working on modernizing and scaling the Mastodon project infrastructure — including joinmastodon.org, mastodon.online, and mastodon.social. Chaput told KrebsOnSecurity that his team was forced to temporarily halt all new registrations for these communities last month after the number of new registrations from Quotpw’s spam campaign started to overwhelm their systems.

“We suddenly went from like three registrations per minute to 900 a minute,” Chaput said. “There was nothing in the Mastodon software to detect that activity, and the protocol is not designed to handle this.”

After that story ran, Chaput said he discovered that the computer code powering Quotpw’s spam botnet (which has since been released as open source) contained an API call to Kopeechka’s service.

“It allows them to pool many bot-created or compromised emails at various providers and offer them to cyber criminals,” Chaput said of Kopeechka. “This is what they used to create thousands of valid Hotmail (and other) addresses when spamming on Mastodon. If you look at the code, it’s really well done with a nice API that forwards you the confirmation link that you can then fake click with your botnet.”

It’s doubtful anyone will make serious money selling email accounts to Kopeechka, unless of course that person already happens to run a botnet and has access to ridiculous numbers of email credentials. And in that sense, this service is genius: It essentially offers scammers a new way to wring extra income from resources that are already plentiful for them.

One final note about Quotpw and the spam botnet that ravaged Chaput’s Mastodon servers last month: Trend Micro just published a report saying Quotpw was spamming to earn money for a Russian-language affiliate program called “Impulse Team,” which pays people to promote cryptocurrency scams.

Launched in 2020, websites under the banner of the Impulse Scam Crypto Project are all essentially “advanced fee” scams that tell people they have earned a cryptocurrency investment credit. Upon registering at the site, visitors are told they need to make a minimum deposit on the service to collect the award. However, those who make the initial investment never hear from the site again, and their money is gone.

Interestingly, Trend Micro says the scammers behind the Impulse Team also appear to be operating a fake reputation service called Scam-Doc[.]com, a website that mimics the legitimate Scamdoc.com site for measuring the trustworthiness and authenticity of various sites. Trend Notes that the phony reputation site routinely gave high trust ratings to a variety of cryptocurrency scam and casino websites.

“We can only suppose that either the same cybercriminals run operations involving both or that several different cybercriminals share the scam-doc[.]com site,” the Trend researchers wrote.

According to the FBI, financial losses from cryptocurrency investment scams dwarfed losses for all other types of cybercrime in 2022, rising from $907 million in 2021 to $2.57 billion last year.