Phishers Spoof USPS, 12 Other Natl’ Postal Services

Recent weeks have seen a sizable uptick in the number of phishing scams targeting U.S. Postal Service (USPS) customers. Here’s a look at an extensive SMS phishing operation that tries to steal personal and financial data by spoofing the USPS, as well as postal services in at least a dozen other countries.

KrebsOnSecurity recently heard from a reader who received an SMS purporting to have been sent by the USPS, saying there was a problem with a package destined for the reader’s address. Clicking the link in the text message brings one to the domain usps.informedtrck[.]com.

The landing page generated by the phishing link includes the USPS logo, and says “Your package is on hold for an invalid recipient address. Fill in the correct address info by the link.” Below that message is a “Click update” button that takes the visitor to a page that asks for more information.

The remaining buttons on the phishing page all link to the real USPS.com website. After collecting your address information, the fake USPS site goes on to request additional personal and financial data.

This phishing domain was recently registered and its WHOIS ownership records are basically nonexistent. However, we can find some compelling clues about the extent of this operation by loading the phishing page in Developer Tools, a set of debugging features built into Firefox, Chrome and Safari that allow one to closely inspect a webpage’s code and operations.

Check out the bottom portion of the screenshot below, and you’ll notice that this phishing site fails to load some external resources, including an image from a link called fly.linkcdn[.]to.

A search on this domain at the always-useful URLscan.io shows that fly.linkcdn[.]to is tied to a slew of USPS-themed phishing domains. Here are just a few of those domains (links defanged to prevent accidental clicking):

usps.receivepost[.]com
usps.informedtrck[.]com
usps.trckspost[.]com
postreceive[.]com
usps.trckpackages[.]com
usps.infortrck[.]com
usps.quicktpos[.]com
usps.postreceive].]com
usps.revepost[.]com
trackingusps.infortrck[.]com
usps.receivepost[.]com
usps.trckmybusi[.]com
postreceive[.]com
tackingpos[.]com
usps.trckstamp[.]com
usa-usps[.]shop
usps.infortrck[.]com
unlistedstampreceive[.]com
usps.stampreceive[.]com
usps.stamppos[.]com
usps.stampspos[.]com
usps.trckmypost[.]com
usps.trckintern[.]com
usps.tackingpos[.]com
usps.posinformed[.]com

As we can see in the screenshot below, the developer tools console for informedtrck[.]com complains that the site is unable to load a Google Analytics code — UA-80133954-3 — which apparently was rejected for pointing to an invalid domain.

The valid domain for that Google Analytics code is the official usps.com website. According to dnslytics.com, that same analytics code has shown up on at least six other nearly identical USPS phishing pages dating back nearly as many years, including onlineuspsexpress[.]com, which DomainTools.com says was registered way back in September 2018 to an individual in Nigeria.

A different domain with that same Google Analytics code that was registered in 2021 is peraltansepeda[.]com, which archive.org shows was running a similar set of phishing pages targeting USPS users. DomainTools.com indicates this website name was registered by phishers based in Indonesia.

DomainTools says the above-mentioned USPS phishing domain stamppos[.]com was registered in 2022 via Singapore-based Alibaba.com, but the registrant city and state listed for that domain says “Georgia, AL,” which is not a real location.

Alas, running a search for domains registered through Alibaba to anyone claiming to reside in Georgia, AL reveals nearly 300 recent postal phishing domains ending in “.top.” These domains are either administrative domains obscured by a password-protected login page, or are .top domains phishing customers of the USPS as well as postal services serving other countries.

Those other nations include the Australia Post, An Post (Ireland), Correos.es (Spain), the Costa Rican post, the Chilean Post, the Mexican Postal Service, Poste Italiane (Italy), PostNL (Netherlands), PostNord (Denmark, Norway and Sweden), and Posti (Finland). A complete list of these domains is available here (PDF).

The Georgia, AL domains at Alibaba also encompass several that spoof sites claiming to collect outstanding road toll fees and fines on behalf of the governments of Australia, New Zealand and Singapore.

An anonymous reader wrote in to say they submitted fake information to the above-mentioned phishing site usps.receivepost[.]com via the malware sandbox any.run. A video recording of that analysis shows that the site sends any submitted data via an automated bot on the Telegram instant messaging service.

The traffic analysis just below the any.run video shows that any data collected by the phishing site is being sent to the Telegram user @chenlun, who offers to sell customized source code for phishing pages. From a review of @chenlun’s other Telegram channels, it appears this account is being massively spammed at the moment — possibly thanks to public attention brought by this story.

Meanwhile, researchers at DomainTools recently published a report on an apparently unrelated but equally sprawling SMS-based phishing campaign targeting USPS customers that appears to be the work of cybercriminals based in Iran.

Phishers tend to cast a wide net and often spoof entities that are broadly used by the local population, and few brands are going to have more household reach than domestic mail services. In June, the United Parcel Service (UPS) disclosed that fraudsters were abusing an online shipment tracking tool in Canada to send highly targeted SMS phishing messages that spoofed the UPS and other brands.

With the holiday shopping season nearly upon us, now is a great time to remind family and friends about the best advice to sidestep phishing scams: Avoid clicking on links or attachments that arrive unbidden in emails, text messages and other mediums. Most phishing scams invoke a temporal element that warns of negative consequences should you fail to respond or act quickly.

If you’re unsure whether the message is legitimate, take a deep breath and visit the site or service in question manually — ideally, using a browser bookmark so as to avoid potential typosquatting sites.

Update: Added information about the Telegram bot and any.run analysis.

‘Snatch’ Ransom Group Exposes Visitor IP Addresses

The victim shaming site operated by the Snatch ransomware group is leaking data about its true online location and internal operations, as well as the Internet addresses of its visitors, KrebsOnSecurity has found. The leaked data suggest that Snatch is one of several ransomware groups using paid ads on Google.com to trick people into installing malware disguised as popular free software, such as Microsoft Teams, Adobe Reader, Mozilla Thunderbird, and Discord.

First spotted in 2018, the Snatch ransomware group has published data stolen from hundreds of organizations that refused to pay a ransom demand. Snatch publishes its stolen data at a website on the open Internet, and that content is mirrored on the Snatch team’s darknet site, which is only reachable using the global anonymity network Tor.

KrebsOnSecurity has learned that Snatch’s darknet site exposes its “server status” page, which includes information about the true Internet addresses of users accessing the website.

Refreshing this page every few seconds shows that the Snatch darknet site generates a decent amount of traffic, often attracting thousands of visitors each day. But by far the most frequent repeat visitors are coming from Internet addresses in Russia that either currently host Snatch’s clear web domain names or recently did.

Probably the most active Internet address accessing Snatch’s darknet site is 193.108.114[.]41, which is a server in Yekaterinburg, Russia that hosts several Snatch domains, including snatchteam[.]top, sntech2ch[.]top, dwhyj2[.]top and sn76930193ch[.]top. It could well be that this Internet address is showing up frequently because Snatch’s clear-web site features a toggle button at the top that lets visitors switch over to accessing the site via Tor.

Another Internet address that showed up frequently in the Snatch server status page was 194.168.175[.]226, currently assigned to Matrix Telekom in Russia. According to DomainTools.com, this address also hosts or else recently hosted the usual coterie of Snatch domains, as well as quite a few domains phishing known brands such as Amazon and Cashapp.

The Moscow Internet address 80.66.64[.]15 accessed the Snatch darknet site all day long, and that address also housed the appropriate Snatch clear-web domains. More interestingly, that address is home to multiple recent domains that appear confusingly similar to known software companies, including libreoff1ce[.]com and www-discord[.]com.

This is interesting because the phishing domains associated with the Snatch ransomware gang were all registered to the same Russian name — Mihail Kolesnikov, a name that is somewhat synonymous with recent phishing domains tied to malicious Google ads.

Kolesnikov could be a nod to a Russian general made famous during Boris Yeltsin’s reign. Either way, it’s clearly a pseudonym, but there are some other commonalities among these domains that may provide insight into how Snatch and other ransomware groups are sourcing their victims.

DomainTools says there are more than 1,300 current and former domain names registered to Mihail Kolesnikov between 2013 and July 2023. About half of the domains appear to be older websites advertising female escort services in major cities around the United States (e.g. the now-defunct pittsburghcitygirls[.]com).

The other half of the Kolesnikov websites are far more recent phishing domains mostly ending in “.top” and “.app” that appear designed to mimic the domains of major software companies, including www-citrix[.]top, www-microsofteams[.]top, www-fortinet[.]top, ibreoffice[.]top, www-docker[.]top, www-basecamp[.]top, ccleaner-cdn[.]top, adobeusa[.]top, and www.real-vnc[.]top.

In August 2023, researchers with Trustwave Spiderlabs said they encountered domains registered to Mihail Kolesnikov being used to disseminate the Rilide information stealer trojan.

But it appears multiple crime groups may be using these domains to phish people and disseminate all kinds of information-stealing malware. In February 2023, Spamhaus warned of a huge surge in malicious ads that were hijacking search results in Google.com, and being used to distribute at least five different families of information stealing trojans, including AuroraStealer, IcedID/Bokbot, Meta Stealer, RedLine Stealer and Vidar.

For example, Spamhaus said victims of these malicious ads would search for Microsoft Teams in Google.com, and the search engine would often return a paid ad spoofing Microsoft or Microsoft Teams as the first result — above all other results. The malicious ad would include a logo for Microsoft and at first glance appear to be a safe and trusted place to download the Microsoft Teams client.

However, anyone who clicked on the result was whisked away instead to mlcrosofteams-us[.]top — yet another malicious domain registered to Mr. Kolesnikov. And while visitors to this website may believe they are only downloading the Microsoft Teams client, the installer file includes a copy of the IcedID malware, which is really good at stealing passwords and authentication tokens from the victim’s web browser.

The founder of the Swiss anti-abuse website abuse.ch told Spamhaus it is likely that some cybercriminals have started to sell “malvertising as a service” on the dark web, and that there is a great deal of demand for this service.

In other words, someone appears to have built a very profitable business churning out and promoting new software-themed phishing domains and selling that as a service to other cybercriminals. Or perhaps they are simply selling any stolen data (and any corporate access) to active and hungry ransomware group affiliates.

The tip about the exposed “server status” page on the Snatch darkweb site came from @htmalgae, the same security researcher who alerted KrebsOnSecurity earlier this month that the darknet victim shaming site run by the 8Base ransomware gang was inadvertently left in development mode.

That oversight revealed not only the true Internet address of the hidden 8Base site (in Russia, naturally), but also the identity of a programmer in Moldova who apparently helped to develop the 8Base code.

@htmalgae said the idea of a ransomware group’s victim shaming site leaking data that they did not intend to expose is deliciously ironic.

“This is a criminal group that shames others for not protecting user data,” @htmalgae said. “And here they are leaking their user data.”

All of the malware mentioned in this story is designed to run on Microsoft Windows devices. But Malwarebytes recently covered the emergence of a Mac-based information stealer trojan called AtomicStealer that was being advertised through malicious Google ads and domains that were confusingly similar to software brands.

Please be extra careful when you are searching online for popular software titles. Cracked, pirated copies of major software titles are a frequent source of infostealer infections, as are these rogue ads masquerading as search results. Make sure to double-check you are actually at the domain you believe you’re visiting *before* you download and install anything.

Stay tuned for Part II of this post, which includes a closer look at the Snatch ransomware group and their founder.

Further reading:

@HTMalgae’s list of the top Internet addresses seen accessing Snatch’s darknet site

Ars Technica: Until Further Notice Think Twice Before Using Google to Download Software

Bleeping Computer: Hackers Abuse Google Ads to Spread Malware in Legit Software

Promising Jobs at the U.S. Postal Service, ‘US Job Services’ Leaks Customer Data

A sprawling online company based in Georgia that has made tens of millions of dollars purporting to sell access to jobs at the United States Postal Service (USPS) has exposed its internal IT operations and database of nearly 900,000 customers. The leaked records indicate the network’s chief technology officer in Pakistan has been hacked for the past year, and that the entire operation was created by the principals of a Tennessee-based telemarketing firm that has promoted USPS employment websites since 2016.

KrebsOnSecurity was recently contacted by a security researcher who said he found a huge tranche of full credit card records exposed online, and that at first glance the domain names involved appeared to be affiliated with the USPS.

Further investigation revealed a long-running international operation that has been emailing and text messaging people for years to sign up at a slew of websites that all promise they can help visitors secure employment at the USPS.

Sites like FederalJobsCenter[.]com also show up prominently in Google search results for USPS employment, and steer applicants toward making credit card “registration deposits” to ensure that one’s application for employment is reviewed. These sites also sell training, supposedly to help ace an interview with USPS human resources.

FederalJobsCenter’s website is full of content that makes it appear the site is affiliated with the USPS, although its “terms and conditions” state that it is not. Rather, the terms state that FederalJobsCenter is affiliated with an entity called US Job Services, which says it is based in Lawrenceville, Ga.

“US Job Services provides guidance, coaching, and live assistance to postal job candidates to help them perform better in each of the steps,” the website explains.

The site says applicants need to make a credit card deposit to register, and that this amount is refundable if the applicant is not offered a USPS job within 30 days after the interview process.

But a review of the public feedback on US Job Services and dozens of similar names connected to this entity over the years shows a pattern of activity: Applicants pay between $39.99 and $100 for USPS job coaching services, and receive little if anything in return. Some reported being charged the same amount monthly.

The U.S. Federal Trade Commission (FTC) has sued several times over the years to disrupt various schemes offering to help people get jobs at the Postal Service. Way back in 1998, the FTC and the USPS took action against several organizations that were selling test or interview preparation services for potential USPS employees.

“Companies promising jobs with the U.S. Postal Service are breaking federal law,” the joint USPS-FTC statement said.

In that 1998 case, the defendants behind the scheme were taking out classified ads in newspapers. Ditto for a case the FTC brought in 2005. By 2008, the USPS job exam preppers had shifted to advertising their schemes mostly online. And in 2013, the FTC won a nearly $5 million judgment against a Kentucky company purporting to offer such services.

Tim McKinlay authored a report last year at Affiliateunguru.com on whether the US Job Services website job-postal[.]com was legitimate or a scam. He concluded it was a scam based on several factors, including that the website listed multiple other names (suggesting it had recently switched names), and that he got nothing from the transaction with the job site.

“They openly admit they’re not affiliated with the US Postal Service, but claim to be experts in the field, and that, just by following the steps on their site, you easily pass the postal exams and get a job in no time,” McKinlay wrote. “But it’s really just a smoke and mirrors game. The site’s true purpose is to collect $46.95 from as many people as possible. And considering how popular this job is, they’re probably making a killing.”

US JOB SERVICES

KrebsOnSecurity was alerted to the data exposure by Patrick Barry, chief information officer at Charlotte, NC based Rebyc Security. Barry said he found that not only was US Job Services leaking its customer payment records in real-time and going back to 2016, but its website also leaked a log file from 2019 containing the site administrator’s contact information and credentials to the site’s back-end database.

Barry shared screenshots of that back-end database, which show the email address for the administrator of US Job Services is tab.webcoder@gmail.com. According to cyber intelligence platform Constella Intelligence, that email address is tied to the LinkedIn profile for a developer in Karachi, Pakistan named Muhammed Tabish Mirza.

A search on tab.webcoder@gmail.com at DomainTools.com reveals that email address was used to register several USPS-themed domains, including postal2017[.]com, postaljobscenter[.]com and usps-jobs[.]com.

Mr. Mirza declined to respond to questions, but the exposed database information was removed from the Internet almost immediately after KrebsOnSecurity shared the offending links.

A “Campaigns” tab on that web panel listed several advertising initiatives tied to US Job Services websites, with names like “walmart drip campaign,” “hiring activity due to virus,” “opt-in job alert SMS,” and “postal job opening.”

Another page on the US Job Services panel included a script for upselling people who call in response to email and text message solicitations, with an add-on program that normally sells for $1,200 but is being “practically given away” for a limited time, for just $49.

“There’s something else we have you can take advantage of that can help you make more money,” the script volunteers. “It’s an easy to use 12-month career development plan and program to follow that will result in you getting any job you want, not just at the post office….anywhere…and then getting promoted rapidly.”

It’s bad enough that US Job Services was leaking customer data: Constella Intelligence says the email address tied to Mr. Mirza shows up in more than a year’s worth of “bot logs” created by a malware infection from the Redline infostealer.

Constella reports that for roughly a year between 2021 and 2022, a Microsoft Windows device regularly used by Mr. Mirza and his colleagues was actively uploading all of the device’s usernames, passwords and authentication cookies to cybercriminals based in Russia.

NEXT LEVEL SUPPORT

The web-based backend for US Job Services lists more than 160 people under its “Users & Teams” tab. This page indicates that access to the consumer and payment data collected by US Job Services is currently granted to several other coders who work with Mr. Mirza in Pakistan, and to multiple executives, contractors and employees working for a call center in Murfreesboro, Tennessee.

The call center — which operates as Nextlevelsupportcenters[.]com and thenextlevelsupport[.]com — curiously has several key associates with a history of registering USPS jobs-related domain names.

The website for NextLevelSupport says it was founded in 2017 by a Gary Plott, whose LinkedIn profile describes him as a seasoned telecommunications industry expert. The leaked backend database for US Job Services says Plott is a current administrator on the system, along with several other Nextlevel founders listed on the company’s site.

Reached via telephone, Plott initially said his company was merely a “white label” call center that multiple clients use to interact with customers, and that the content their call center is responsible for selling on behalf of US Job Services was not produced by NextLevelSupport.

“A few years ago, we started providing support for this postal product,” Plott said. “We didn’t develop the content but agreed we would support it.”

Interestingly, DomainTools says the Gmail address used by Plott in the US Jobs system was also used to register multiple USPS job-related domains, including postaljobssite[.]com, postalwebsite[.]com, usps-nlf[.]com, usps-nla[.]com.

Asked to reconcile this with his previous statement, Plott said he never did anything with those sites but acknowledged that his company did decide to focus on the US Postal jobs market from the very beginning.

Plott said his company never refuses to issue a money-back request from a customer, because doing so would result in costly chargebacks for NextLevel (and presumably for the many credit card merchant accounts apparently set up by Mr. Mirza).

“We’ve never been deceptive,” Plott said, noting that customers of the US Job Services product receive a digital download with tips on how to handle a USPS interview, as well as unlimited free telephone support if they need it.

“We’ve never told anyone we were the US Postal Service,” Plott continued. “We make sure people fully understand that they are not required to buy this product, but we think we can help you and we have testimonials from people we have helped. But ultimately you as the customer make that decision.”

An email address in the US Job Services teams page for another user — Stephanie Dayton — was used to register the domains postalhiringreview[.]com, and postalhiringreviewboard[.]org back in 2014. Reached for comment, Ms. Dayton said she has provided assistance to Next Level Support Centers with their training and advertising, but never in the capacity as an employee.

Perhaps the most central NextLevel associate who had access to US Job Services was Russell Ramage, a telemarketer from Warner Robins, Georgia. Ramage is listed in South Carolina incorporation records as the owner of a now-defunct call center service called Smart Logistics, a company whose name appears in the website registration records for several early and long-running US Job Services sites.

The leaked records show the email address used by Ramage also registered multiple USPS jobs-related domains, including postalhiringcenter[.]com, postalhiringreviews[.]com, postaljobs-email[.]com, and postaljobssupport1[.]com.

A review of business incorporation records in Georgia indicate Ramage was the registered agent for at least three USPS-related companies over the years, including Postal Career Placement LLC, Postal Job Services Inc., and Postal Operations Inc. All three companies were founded in 2015, and are now dissolved.

An obituary dated February 2023 says Russell Ramage recently passed away at the age of 41. No cause of death was stated, but the obituary goes on to say that Russ “Rusty” Ramage was “preceded in death by his mother, Anita Lord Ramage, pets, Raine and Nola and close friends, Nicole Reeves and Ryan Rawls.”

In 2014, then 33-year-old Ryan “Jootgater” Rawls of Alpharetta, Georgia pleaded guilty to conspiring to distribute controlled substances. Rawls also grew up in Warner Robins, and was one of eight suspects charged with operating a secret darknet narcotics ring called the Farmer’s Market, which federal prosecutors said trafficked in millions of dollars worth of controlled substances.

Reuters reported that an eighth suspect in that case had died by the time of Rawls’ 2014 guilty plea, although prosecutors declined to offer further details about that. According to his obituary, Ryan Christopher Rawls died at the age of 38 on Jan. 28, 2019.

In a comment on Ramage’s memorial wall, Stephanie Dayton said she began working with Ramage in 2006.

“Our friendship far surpassed a working one, we had a very close bond and became like brother and sister,” Dayton wrote. “I loved Russ deeply and he was like family. He was truly one of the best human beings I have ever known. He was kind and sweet and truly cared about others. Never met anyone like him. He will be truly missed. RIP brother.”

The FTC and USPS note that while applicants for many entry-level postal jobs are required to take a free postal exam, the tests are usually offered only every few years in any particular district, and there are no job placement guarantees based on score.

“If applicants pass the test by scoring at least 70 out of 100, they are placed on a register, ranked by their score,” the FTC explained. “When a position becomes open, the local post office looks to the applicable register for that geographic location and calls the top three applicants. The score is only one of many criteria taken into account for employment. The exams test general aptitude, something that cannot necessarily be increased by studying.”

The FTC says anyone interested in a job at the USPS should inquire at their local postal office, where applicants generally receive a free packet of information about required exams. More information about job opportunities at the postal service is available at the USPS’s careers website.

Michael Martel, spokesperson for the United States Postal Inspection Service, said in a written statement that the USPS has no affiliation with the websites or companies named in this story.

“To learn more about employment with USPS, visit USPS.com/careers,” Martel wrote. “If you are the victim of a crime online report it to the FBI’s Internet Crime Complaint Center (IC3) at www.ic3.gov. To report fraud committed through or toward the USPS, its employees, or customers, report it to the United States Postal Inspection Service (USPIS) at www.uspis.gov/report.”

According to the leaked back-end server for US Job Services, here is a list of the current sites selling this product:

usjobshelpcenter[.]com
usjobhelpcenter[.]com
job-postal[.]com
localpostalhiring[.]com
uspostalrecruitment[.]com
postalworkerjob[.]com
next-level-now[.]com
postalhiringcenters[.]com
postofficehiring[.]com
postaljobsplacement[.]com
postal-placement[.]com
postofficejobopenings[.]com
postalexamprep[.]com
postaljobssite[.]com
postalwebsite[.]com
postalcareerscenters[.]com
postal-hiring[.]com
postal-careers[.]com
postal-guide[.]com
postal-hiring-guide[.]com
postal-openings[.]com
postal-placement[.]com
postofficeplacements[.]com
postalplacementservices[.]com
postaljobs20[.]com
postal-jobs-placement[.]com
postaljobopenings[.]com
postalemployment[.]com
postaljobcenters[.]com
postalmilitarycareers[.]com
epostaljobs[.]com
postal-job-center[.]com
postalcareercenter[.]com
postalhiringcenters[.]com
postal-job-center[.]com
postalcareercenter[.]com
postalexamprep[.]com
postalplacementcenters[.]com
postalplacementservice[.]com
postalemploymentservices[.]com
uspostalhiring[.]com

3CX Breach Was a Double Supply Chain Compromise

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.

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.

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.