We learned some remarkable new details this week about the recent supply-chain attack on VoIP software provider 3CX. The lengthy, complex intrusion has all the makings of a cyberpunk spy novel: North Korean hackers using legions of fake executive accounts on LinkedIn to lure people into opening malware disguised as a job offer; malware targeting Mac and Linux users working at defense and cryptocurrency firms; and software supply-chain attacks nested within earlier supply chain attacks.
Researchers at ESET say this job offer from a phony HSBC recruiter on LinkedIn was North Korean malware masquerading as a PDF file.
In late March 2023, 3CX disclosed that its desktop applications for both Windows and macOS were compromised with malicious code that gave attackers the ability to download and run code on all machines where the app was installed. 3CX says it has more than 600,000 customers and 12 million users in a broad range of industries, including aerospace, healthcare and hospitality.
3CX hired incident response firm Mandiant, which released a report on Wednesday that said the compromise began in 2022 when a 3CX employee installed a malware-laced software package distributed via an earlier software supply chain compromise that began with a tampered installer for X_TRADER, a software package provided by Trading Technologies.
“This is the first time Mandiant has seen a software supply chain attack lead to another software supply chain attack,” reads the April 20 Mandiant report.
Mandiant found the earliest evidence of compromise uncovered within 3CX’s network was through the VPN using the employee’s corporate credentials, two days after the employee’s personal computer was compromised.
“Eventually, the threat actor was able to compromise both the Windows and macOS build environments,” 3CX said in an April 20 update on their blog.
Mandiant concluded that the 3CX attack was orchestrated by the North Korean state-sponsored hacking group known as Lazarus, a determination that was independently reached earlier by researchers at Kaspersky Lab and Elastic Security.
Mandiant found the compromised 3CX software would download malware that sought out new instructions by consulting encrypted icon files hosted on GitHub. The decrypted icon files revealed the location of the malware’s control server, which was then queried for a third stage of the malware compromise — a password stealing program dubbed ICONICSTEALER.
The double supply chain compromise that led to malware being pushed out to some 3CX customers. Image: Mandiant.
Meanwhile, the security firm ESET today published research showing remarkable similarities between the malware used in the 3CX supply chain attack and Linux-based malware that was recently deployed via fake job offers from phony executive profiles on LinkedIn. The researchers said this was the first time Lazarus had been spotted deploying malware aimed at Linux users.
As reported in a series last summer here, LinkedIn has been inundated this past year by fake executive profiles for people supposedly employed at a range of technology, defense, energy and financial companies. In many cases, the phony profiles spoofed chief information security officers at major corporations, and some attracted quite a few connections before their accounts were terminated.
Mandiant, Proofpoint and other experts say Lazarus has long used these bogus LinkedIn profiles to lure targets into opening a malware-laced document that is often disguised as a job offer. This ongoing North Korean espionage campaign using LinkedIn was first documented in August 2020 by ClearSky Security, which said the Lazarus group operates dozens of researchers and intelligence personnel to maintain the campaign globally.
Microsoft Corp., which owns LinkedIn, said in September 2022 that it had detected a wide range of social engineering campaigns using a proliferation of phony LinkedIn accounts. Microsoft said the accounts were used to impersonate recruiters at technology, defense and media companies, and to entice people into opening a malicious file. Microsoft found the attackers often disguised their malware as legitimate open-source software like Sumatra PDF and the SSH client Putty.
Microsoft attributed those attacks to North Korea’s Lazarus hacking group, although they’ve traditionally referred to this group as “ZINC“. That is, until earlier this month, when Redmond completely revamped the way it names threat groups; Microsoft now references ZINC as “Diamond Sleet.”
The ESET researchers said they found a new fake job lure tied to an ongoing Lazarus campaign on LinkedIn designed to compromise Linux operating systems. The malware was found inside of a document that offered an employment contract at the multinational bank HSBC.
“A few weeks ago, a native Linux payload was found on VirusTotal with an HSBC-themed PDF lure,” wrote ESET researchers Peter Kalnai and Marc-Etienne M.Leveille. “This completes Lazarus’s ability to target all major desktop operating systems. In this case, we were able to reconstruct the full chain, from the ZIP file that delivers a fake HSBC job offer as a decoy, up until the final payload.”
ESET said the malicious PDF file used in the scheme appeared to have a file extension of “.pdf,” but that this was a ruse. ESET discovered that the dot in the filename wasn’t a normal period but instead a Unicode character (U+2024) representing a “leader dot,” which is often used in tables of contents to connect section headings with the page numbers on which those sections begin.
“The use of the leader dot in the filename was probably an attempt to trick the file manager into treating the file as an executable instead of a PDF,” the researchers continued. “This could cause the file to run when double-clicked instead of opening it with a PDF viewer.”
ESET said anyone who opened the file would see a decoy PDF with a job offer from HSBC, but in the background the executable file would download additional malware payloads. The ESET team also found the malware was able to manipulate the program icon displayed by the malicious PDF, possibly because fiddling with the file extension could cause the user’s system to display a blank icon for the malware lure.
Kim Zetter, a veteran Wired.com reporter and now independent security journalist, interviewed Mandiant researchers who said they expect “many more victims” will be discovered among the customers of Trading Technologies and 3CX now that news of the compromised software programs is public.
“Mandiant informed Trading Technologies on April 11 that its X_Trader software had been compromised, but the software maker says it has not had time to investigate and verify Mandiant’s assertions,” Zetter wrote in her Zero Day newsletter on Substack. For now, it remains unclear whether the compromised X_Trader software was downloaded by people at other software firms.
If there’s a silver lining here, the X_Trader software had been decommissioned in April 2020 — two years before the hackers allegedly embedded malware in it.
“The company hadn’t released new versions of the software since that time and had stopped providing support for the product, making it a less-than-ideal vector for the North Korean hackers to infect customers,” Zetter wrote.
AMLBot, a service that helps businesses avoid transacting with cryptocurrency wallets that have been sanctioned for cybercrime activity, said an investigation published by KrebsOnSecurity last year helped it shut down three dark web services that secretly resold its technology to help cybercrooks avoid detection by anti-money laundering systems.
Antinalysis, as it existed in 2021.
In August 2021, KrebsOnSecurity published “New Anti Anti-Money Laundering Services for Crooks,” which examined Antinalysis, a service marketed on cybercrime forums that purported to offer a glimpse of how one’s payment activity might be flagged by law enforcement agencies and private companies that track and trace cryptocurrency transactions.
“Worried about dirty funds in your BTC address? Come check out Antinalysis, the new address risk analyzer,” read the service’s opening announcement. “This service is dedicated to individuals that have the need to possess complete privacy on the blockchain, offering a perspective from the opponent’s point of view in order for the user to comprehend the possibility of his/her funds getting flagged down under autocratic illegal charges.”
Antinalysis allows free lookups, but anyone wishing to conduct bulk look-ups has to pay at least USD $3, with a minimum $30 purchase. Other plans go for as high as $6,000 for 5,000 requests. Nick Bax, a security researcher who specializes in tracing cryptocurrency transactions, told KrebsOnSecurity at the time that Antinalysis was likely a clone of AMLBot because the two services generated near-identical results.
AMLBot shut down Antinalysis’s access just hours after last year’s story went live. However, Antinalysis[.]org remains online and accepting requests, as does the service’s Tor-based domain, and it is unclear how those services are sourcing their information.
AMLBot spokesperson Polina Smoliar said the company undertook a thorough review after that discovery, and in the process found two other services similar to Antinalysis that were reselling their application programming interface (API) access to cybercrooks.
Smoliar said that following the revelations about Antinalysis, AMLBot audited its entire client base, and implemented the ability to provide APIs only after a contract is signed and the client has been fully audited. AMLBot said it also instituted 24/7 monitoring of all client transactions.
“As a result of these actions, two more services with the name AML (the same as AMLBot has) were found to be involved in fraudulent schemes,” Smoliar said. “Information about the fraudsters was also sent to key market participants, and their transaction data was added to the tracking database to better combat money laundering.”
The Antinalysis homepage and chatter on the cybercrime forums indicates the service was created by a group of coders known as the Incognito Team. Tom Robinson, co-founder of the blockchain intelligence firm Elliptic, said the creator of Antinalysis is also one of the developers of Incognito Market, a darknet marketplace specializing in the sale of narcotics.
“Incognito was launched in late 2020, and accepts payments in both Bitcoin and Monero, a cryptoasset offering heightened anonymity,” Robinson said. “The launch of Antinalysis likely reflects the difficulties faced by the market and its vendors in cashing out their Bitcoin proceeds.”
U.S. state and federal investigators are being inundated with reports from people who’ve lost hundreds of thousands or millions of dollars in connection with a complex investment scam known as “pig butchering,” wherein people are lured by flirtatious strangers online into investing in cryptocurrency trading platforms that eventually seize any funds when victims try to cash out.
The term “pig butchering” refers to a time-tested, heavily scripted, and human-intensive process of using fake profiles on dating apps and social media to lure people into investing in elaborate scams. In a more visceral sense, pig butchering means fattening up a prey before the slaughter.
“The fraud is named for the way scammers feed their victims with promises of romance and riches before cutting them off and taking all their money,” the Federal Bureau of Investigation (FBI) warned in April 2022. “It’s run by a fraud ring of cryptocurrency scammers who mine dating apps and other social media for victims and the scam is becoming alarmingly popular.”
As documented in a series of investigative reports published over the past year across Asia, the people creating these phony profiles are largely men and women from China and neighboring countries who have been kidnapped and trafficked to places like Cambodia, where they are forced to scam complete strangers over the Internet — day after day.
The most prevalent pig butchering scam today involves sophisticated cryptocurrency investment platforms, where investors invariably see fantastic returns on their deposits — until they try to withdraw the funds. At that point, investors are told they owe huge tax bills. But even those who pay the phony levies never see their money again.
The come-ons for these scams are prevalent on dating sites and apps, but they also frequently start with what appears to be a wayward SMS — such as an instant message about an Uber ride that never showed. Or a reminder from a complete stranger about a planned meetup for coffee. In many ways, the content of the message is irrelevant; the initial goal to simply to get the recipient curious enough to respond in some way.
Those who respond are asked to continue the conversation via WhatsApp, where an attractive, friendly profile of the opposite gender will work through a pre-set script that is tailored to their prey’s apparent socioeconomic situation. For example, a divorced, professional female who responds to these scams will be handled with one profile type and script, while other scripts are available to groom a widower, a young professional, or a single mom.
That’s according to Erin West, deputy district attorney for Santa Clara County in Northern California. West said her office has been fielding a large number of pig butchering inquiries from her state, but also from law enforcement entities around the country that are ill-equipped to investigate such fraud.
“The people forced to perpetrate these scams have a guide and a script, where if your victim is divorced say this, or a single mom say this,” West said. “The scale of this is so massive. It’s a major problem with no easy answers, but also with victim volumes I’ve never seen before. With victims who are really losing their minds and in some cases are suicidal.”
West is a key member of REACT, a task force set up to tackle especially complex forms of cyber theft involving virtual currencies. West said the initial complaints from pig butchering victims came early this year.
“I first thought they were one-off cases, and then I realized we were getting these daily,” West said. “A lot of them are being reported to local agencies that don’t know what to do with them, so the cases languish.”
West said pig butchering victims are often quite sophisticated and educated people.
“One woman was a university professor who lost her husband to COVID, got lonely and was chatting online, and eventually ended up giving away her retirement,” West recalled of a recent case. “There are just horrifying stories that run the gamut in terms of victims, from young women early in their careers, to senior citizens and even to people working in the financial services industry.”
In some cases reported to REACT, the victims said they spent days or weeks corresponding with the phony WhatsApp persona before the conversation shifted to investing.
“They’ll say ‘Hey, this is the food I’m eating tonight’ and the picture they share will show a pretty setting with a glass of wine, where they’re showcasing an enviable lifestyle but not really mentioning anything about how they achieved that,” West said. “And then later, maybe a few hours or days into the conversation, they’ll say, ‘You know I made some money recently investing in crypto,’ kind of sliding into the topic as if this wasn’t what they were doing the whole time.”
Curious investors are directed toward elaborate and official-looking online crypto platforms that appear to have thousands of active investors. Many of these platforms include extensive study materials and tutorials on cryptocurrency investing. New users are strongly encouraged to team up with more seasoned investors on the platform, and to make only small investments that they can afford to lose.
The now-defunct homepage of xtb-market[.]com, a scam cryptocurrency platform tied to a pig butchering scheme.
“They’re able to see some value increase, and maybe even be allowed to take out that value increase so that they feel comfortable about the situation,” West said. Some investors then need little encouragement to deposit additional funds, which usually generate increasingly higher “returns.”
West said many crypto trading platforms associated with pig butchering scams appear to have been designed much like a video game, where investor hype is built around upcoming “trading opportunities” that hint at even more fantastic earnings.
“There are bonus levels and VIP levels, and they’ll build hype and a sense of frenzy into the trading,” West said. “There are definitely some psychological mechanisms at work to encourage people to invest more.”
“What’s so devastating about many of the victims is they lose that sense of who they are,” she continued. “They thought they were a savvy, sophisticated person, someone who’s sort of immune to scams. I think the large scale of the trickery and psychological manipulation being used here can’t be understated. It’s like nothing I’ve seen before.”
Courtney Nolan, a divorced mother of three daughters, says she lost more than $5 million to a pig butchering scam. Nolan lives in St. Louis and has a background in investment finance, but only started investing in cryptocurrencies in the past year.
Nolan’s case may be especially bad because she was already interested in crypto investing when the scammer reached out. At the time, Bitcoin was trading at or near all-time highs of nearly $68,000 per coin.
Nolan said her nightmare began in late 2021 with a Twitter direct message from someone who was following many of the same cryptocurrency influencers she followed. Her fellow crypto enthusiast then suggested they continue their discussion on WhatsApp. After much back and forth about his trading strategies, her new friend agreed to mentor her on how to make reliable profits using the crypto trading platform xtb.com.
“I had dabbled in leveraged trading before, but his mentor program gave me over 100 pages of study materials and agreed to walk me through their investment strategies over the course of a year,” Nolan told KrebsOnSecurity.
Nolan’s mentor had her create an account website xtb-market[.]com, which was made to be confusingly similar to XTB’s official platform. The site promoted several different investment packages, including a “starter plan” that involves a $5,250 up-front investment and promises more than 15 percent return across four separate trading bursts.
Platinum plans on xtb-market promised a whopping 45 percent ROI, with a minimum investment of $265,000. The site also offered a generous seven percent commission for referrals, which encouraged new investors to recruit others.
The now-defunct xtb-market[.]com.
While chatting via WhatsApp, Nolan and her mentor would trade side by side in xtb-market, initially with small investments ranging from $500 to $5,000. When those generated hefty returns, Nolan made bigger deposits. On several occasions she was able to withdraw amounts ranging from $10,000 to $30,000.
But after investing more than $4.5 million of her own money over nearly four months, Nolan found her account was suddenly frozen. She was then issued a tax statement saying she owed nearly $500,000 in taxes before she could reactivate her account or access her funds.
Nolan said it seems obvious in hindsight that she should never have paid the tax bill. Because xtb-market and her mentor cut all communications with her after that, and the entire website disappeared just a few weeks later.
Justin Maile, an investigation partner manager at Chainalysis, told Vice News that the tax portion of the pig butchering scam relies on the “sunk costs fallacy,” when people are reluctant to abandon a failing strategy or course of action because they have already invested heavily in it.
“Once the victim starts getting skeptical or tries to withdraw their funds, they are often told that they have to pay tax on the gains before funds can be unlocked,” Maile told Vice News. “The scammers will try to get any last payments out of the victims by exploiting the sunk cost fallacy and dangling huge profits in front of them.”
Vice recently published an in-depth report on pig butchering’s link to organized crime gangs in Asia that lure young job seekers with the promise of customer service jobs in call centers. Instead, those who show up at the appointed place and time are taken on long car rides and/or forced hikes across the borders into Cambodia, where they are pressed into indentured servitude.
Vice found many of the people forced to work in pig-butchering scams are being held in Chinese-owned casinos operating in Cambodia. Many of those casinos were newly built when the Covid pandemic hit. As the new casinos and hotels sat empty, organized crime groups saw an opportunity to use these facilities to generate huge income streams, and many foreign travelers stranded in neighboring countries were eventually trafficked to these scam centers.
Vice reports:
“While figures on the number of people in scam centers in Cambodia is unknown, best estimates pieced together from various sources point to the tens of thousands across scam centers in Sihanoukville, Phnom Penh, and sites in border regions Poipet and Bavet. In April, Thailand’s assistant national police commissioner said 800 Thai citizens had been rescued from scam centers in Cambodia in recent months, with a further 1,000 citizens still trapped across the country. One Vietnamese worker estimated 300 of his compatriots were held on just one floor in a tall office block hosting scam operations.”
“…within Victory Paradise Resort alone there were 7,000 people, the majority from mainland China, but also Indonesians, Singaporeans and Filipinos. According to the Khmer Times, one 10-building complex of high-rises in Sihanoukville, known as The China Project, holds between 8,000 to 10,000 people participating in various scams—a workforce that would generate profits around the $1 billion mark each year at $300 per worker per day.”
REACTs’ West said while there are a large number of pig butchering victims reporting their victimization to the FBI, very few are receiving anything more than instructions about filing a complaint with the FBI’s Internet Crime Complaint Center (IC3), which keeps track of cybercrime losses and victims.
“There’s a huge gap in victims that are seeing any kind of service at all, where they’re reporting to the FBI but not being able to talk to anyone,” she said. “They’re filling out the IC3 form and never hearing back. It sort of feels like the federal government is ignoring this, so people are going to local agencies, which are sending these victims our way.”
For many younger victims of pig butchering, even losses of a few thousand dollars can be financially devastating. KrebsOnSecurity recently heard from two different readers who said they were in their 20s and lost more than $40,000 each when the investment platforms they were trading on vanished with their money.
The FBI can often bundle numerous IC3 complaints involving the same assailants and victims into a single case for federal prosecutors to pursue the guilty, and/or try to recapture what was stolen. In general, however, victims of crypto crimes rarely see that money again, or if they do it can take many years.
“The next piece is what can we actually do with these cases,” West said. “We used to frame success as getting bad people behind bars, but these cases leave us as law enforcement with not a lot of opportunity there.”
West said the good news is U.S. authorities are seeing some success in freezing cryptocurrency wallets suspected of being tied to large-scale cybercriminal operations. Indeed, Nolan told KrebsOnSecurity that her losses were substantial enough to warrant an official investigation by the FBI, which she says has since taken steps to freeze at least some of the assets tied to xtb-market[.]com.
Likewise, West said she was recently able to freeze cryptocurrency funds stolen from some pig butchering victims, and now REACT is focusing on helping state and local authorities learn how to do the same.
“It’s important to be able to mobilize quickly and know how to freeze and seize crypto and get it back to its rightful owner,” West said. “We definitely have made seizures in cases involving pig butchering, but we haven’t gotten that back to the rightful owners yet.”
In April, the FBI warned Internet users to be on guard against pig butchering scams, which it said attracts victims with “promises of romance and riches” before duping them out of their money. The IC3 said it received more than 4,300 complaints related to crypto-romance scams, resulting in losses of more than $429 million.
Here are some common elements of a pig butchering scam:
–Dating apps: Pig-butchering attempts are common on dating apps, but they can begin with almost any type of communication, including SMS text messages.
–WhatsApp: In virtually all documented cases of pig butchering, the target is moved fairly quickly into chatting with the scammer via WhatsApp.
–No video: The scammers will come up with all kinds of excuses not to do a video call. But they will always refuse.
–Investment chit-chat: Your contact (eventually) claims to have inside knowledge about the cryptocurrency market and can help you make money.
The FBI’s tips on avoiding crypto scams:
-Never send money, trade, or invest based on the advice of someone you have only met online.
-Don’t talk about your current financial status to unknown and untrusted people.
-Don’t provide your banking information, Social Security Number, copies of your identification or passport, or any other sensitive information to anyone online or to a site you do not know is legitimate.
-If an online investment or trading site is promoting unbelievable profits, it is most likely that—unbelievable.
-Be cautious of individuals who claim to have exclusive investment opportunities and urge you to act fast.