Fake Lawsuit Threat Exposes Privnote Phishing Sites

A cybercrook who has been setting up websites that mimic the self-destructing message service privnote.com accidentally exposed the breadth of their operations recently when they threatened to sue a software company. The disclosure revealed a profitable network of phishing sites that behave and look like the real Privnote, except that any messages containing cryptocurrency addresses will be automatically altered to include a different payment address controlled by the scammers.

Launched in 2008, privnote.com employs technology that encrypts each message so that even Privnote itself cannot read its contents. And it doesn’t send or receive messages. Creating a message merely generates a link. When that link is clicked or visited, the service warns that the message will be gone forever after it is read.

Privnote’s ease-of-use and popularity among cryptocurrency enthusiasts has made it a perennial target of phishers, who erect Privnote clones that function more or less as advertised but also quietly inject their own cryptocurrency payment addresses when a note is created that contains crypto wallets.

Last month, a new user on GitHub named fory66399 lodged a complaint on the “issues” page for MetaMask, a software cryptocurrency wallet used to interact with the Ethereum blockchain. Fory66399 insisted that their website — privnote[.]co — was being wrongly flagged by MetaMask’s “eth-phishing-detect” list as malicious.

“We filed a lawsuit with a lawyer for dishonestly adding a site to the block list, damaging reputation, as well as ignoring the moderation department and ignoring answers!” fory66399 threatened. “Provide evidence or I will demand compensation!”

MetaMask’s lead product manager Taylor Monahan replied by posting several screenshots of privnote[.]co showing the site did indeed swap out any cryptocurrency addresses.

After being told where they could send a copy of their lawsuit, Fory66399 appeared to become flustered, and proceeded to mention a number of other interesting domain names:

You sent me screenshots from some other site! It’s red!!!!
The tornote.io website has a different color altogether
The privatenote,io website also has a different color! What’s wrong?????

A search at DomainTools.com for privatenote[.]io shows it has been registered to two names over as many years, including Andrey Sokol from Moscow and Alexandr Ermakov from Kiev. There is no indication these are the real names of the phishers, but the names are useful in pointing to other sites targeting Privnote since 2020.

DomainTools says other domains registered to Alexandr Ermakov include pirvnota[.]com, privatemessage[.]net, privatenote[.]io, and tornote[.]io.

The registration records for pirvnota[.]com at one point were updated from Andrey Sokol to “BPW” as the registrant organization, and “Tambov district” in the registrant state/province field. Searching DomainTools for domains that include both of these terms reveals pirwnote[.]com.

Other Privnote phishing domains that also phoned home to the same Internet address as pirwnote[.]com include privnode[.]com, privnate[.]com, and prevnóte[.]com. Pirwnote[.]com is currently selling security cameras made by the Chinese manufacturer Hikvision, via an Internet address based in Hong Kong.

It appears someone has gone to great lengths to make tornote[.]io seem like a legitimate website. For example, this account at Medium has authored more than a dozen blog posts in the past year singing the praises of Tornote as a secure, self-destructing messaging service. However, testing shows tornote[.]io will also replace any cryptocurrency addresses in messages with their own payment address.

These malicious note sites attract visitors by gaming search engine results to make the phishing domains appear prominently in search results for “privnote.” A search in Google for “privnote” currently returns tornote[.]io as the fifth result. Like other phishing sites tied to this network, Tornote will use the same cryptocurrency addresses for roughly 5 days, and then rotate in new payment addresses.

Throughout 2023, Tornote was hosted with the Russian provider DDoS-Guard, at the Internet address 186.2.163[.]216. A review of the passive DNS records tied to this address shows that apart from subdomains dedicated to tornote[.]io, the main other domain at this address was hkleaks[.]ml.

In August 2019, a slew of websites and social media channels dubbed “HKLEAKS” began doxing the identities and personal information of pro-democracy activists in Hong Kong. According to a report (PDF) from Citizen Lab, hkleaks[.]ml was the second domain that appeared as the perpetrators began to expand the list of those doxed.

DomainTools shows there are more than 1,000 other domains whose registration records include the organization name “BPW” and “Tambov District” as the location. Virtually all of those domains were registered through one of two registrars — Hong Kong-based Nicenic and Singapore-based WebCC — and almost all appear to be phishing or pill-spam related.

Among those is rustraitor[.]info, a website erected after Russia invaded Ukraine in early 2022 that doxed Russians perceived to have helped the Ukrainian cause.

In keeping with the overall theme, these phishing domains appear focused on stealing usernames and passwords to some of the cybercrime underground’s busiest shops, including Brian’s Club. What do all the phished sites have in common? They all accept payment via virtual currencies.

It appears MetaMask’s Monahan made the correct decision in forcing these phishers to tip their hand: Among the websites at that DDoS-Guard address are multiple MetaMask phishing domains, including metarrnask[.]com, meternask[.]com, and rnetamask[.]com.

How profitable are these private note phishing sites? Reviewing the four malicious cryptocurrency payment addresses that the attackers swapped into notes passed through privnote[.]co (as pictured in Monahan’s screenshot above) shows that between March 15 and March 19, 2024, those address raked in and transferred out nearly $18,000 in cryptocurrencies. And that’s just one of their phishing websites.

Experts Fear Crooks are Cracking Keys Stolen in LastPass Breach

In November 2022, the password manager service LastPass disclosed a breach in which hackers stole password vaults containing both encrypted and plaintext data for more than 25 million users. Since then, a steady trickle of six-figure cryptocurrency heists targeting security-conscious people throughout the tech industry has led some security experts to conclude that crooks likely have succeeded at cracking open some of the stolen LastPass vaults.

Taylor Monahan is lead product manager of MetaMask, a popular software cryptocurrency wallet used to interact with the Ethereum blockchain. Since late December 2022, Monahan and other researchers have identified a highly reliable set of clues that they say connect recent thefts targeting more than 150 people. Collectively, these individuals have been robbed of more than $35 million worth of crypto.

Monahan said virtually all of the victims she has assisted were longtime cryptocurrency investors, and security-minded individuals. Importantly, none appeared to have suffered the sorts of attacks that typically preface a high-dollar crypto heist, such as the compromise of one’s email and/or mobile phone accounts.

“The victim profile remains the most striking thing,” Monahan wrote. “They truly all are reasonably secure. They are also deeply integrated into this ecosystem, [including] employees of reputable crypto orgs, VCs [venture capitalists], people who built DeFi protocols, deploy contracts, run full nodes.”

Monahan has been documenting the crypto thefts via Twitter/X since March 2023, frequently expressing frustration in the search for a common cause among the victims. Then on Aug. 28, Monahan said she’d concluded that the common thread among nearly every victim was that they’d previously used LastPass to store their “seed phrase,” the private key needed to unlock access to their cryptocurrency investments.

Armed with your secret seed phrase, anyone can instantly access all of the cryptocurrency holdings tied to that cryptographic key, and move the funds to anywhere they like.

Which is why the best practice for many cybersecurity enthusiasts has long been to store their seed phrases either in some type of encrypted container — such as a password manager — or else inside an offline, special-purpose hardware encryption device, such as a Trezor or Ledger wallet.

“The seed phrase is literally the money,” said Nick Bax, director of analytics at Unciphered, a cryptocurrency wallet recovery company. “If you have my seed phrase, you can copy and paste that into your wallet, and then you can see all my accounts. And you can transfer my funds.”

Bax said he closely reviewed the massive trove of cryptocurrency theft data that Taylor Monahan and others have collected and linked together.

“It’s one of the broadest and most complex cryptocurrency investigations I’ve ever seen,” Bax said. “I ran my own analysis on top of their data and reached the same conclusion that Taylor reported. The threat actor moved stolen funds from multiple victims to the same blockchain addresses, making it possible to strongly link those victims.”

Bax, Monahan and others interviewed for this story say they’ve identified a unique signature that links the theft of more than $35 million in crypto from more than 150 confirmed victims, with roughly two to five high-dollar heists happening each month since December 2022.

KrebsOnSecurity has reviewed this signature but is not publishing it at the request of Monahan and other researchers, who say doing so could cause the attackers to alter their operations in ways that make their criminal activity more difficult to track.

But the researchers have published findings about the dramatic similarities in the ways that victim funds were stolen and laundered through specific cryptocurrency exchanges. They also learned the attackers frequently grouped together victims by sending their cryptocurrencies to the same destination crypto wallet.

By identifying points of overlap in these destination addresses, the researchers were then able to track down and interview new victims. For example, the researchers said their methodology identified a recent multi-million dollar crypto heist victim as an employee at Chainalysis, a blockchain analysis firm that works closely with law enforcement agencies to help track down cybercriminals and money launderers.

Chainalysis confirmed that the employee had suffered a high-dollar cryptocurrency heist late last month, but otherwise declined to comment for this story.

Bax said the only obvious commonality between the victims who agreed to be interviewed was that they had stored the seed phrases for their cryptocurrency wallets in LastPass.

“On top of the overlapping indicators of compromise, there are more circumstantial behavioral patterns and tradecraft which are also consistent between different thefts and support the conclusion,” Bax told KrebsOnSecuirty. “I’m confident enough that this is a real problem that I’ve been urging my friends and family who use LastPass to change all of their passwords and migrate any crypto that may have been exposed, despite knowing full well how tedious that is.”

LastPass declined to answer questions about the research highlighted in this story, citing an ongoing law enforcement investigation and pending litigation against the company in response to its 2022 data breach.

“Last year’s incident remains the subject of an ongoing investigation by law enforcement and is also the subject of pending litigation,” LastPass said in a written statement provided to KrebsOnSecurity. “Since last year’s attack on LastPass, we have remained in contact with law enforcement and continue to do so.”

Their statement continues:

“We have shared various technical information, Indicators of Compromise (IOCs), and threat actor tactics, techniques, and procedures (TTPs) with our law enforcement contacts as well as our internal and external threat intelligence and forensic partners in an effort to try and help identify the parties responsible. In the meantime, we encourage any security researchers to share any useful information they believe they may have with our Threat Intelligence team by contacting securitydisclosure@lastpass.com.”

THE LASTPASS BREACH(ES)

On August 25, 2022, LastPass CEO Karim Toubba wrote to users that the company had detected unusual activity in its software development environment, and that the intruders stole some source code and proprietary LastPass technical information. On Sept. 15, 2022, LastPass said an investigation into the August breach determined the attacker did not access any customer data or password vaults.

But on Nov. 30, 2022, LastPass notified customers about another, far more serious security incident that the company said leveraged data stolen in the August breach. LastPass disclosed that criminal hackers had compromised encrypted copies of some password vaults, as well as other personal information.

In February 2023, LastPass disclosed that the intrusion involved a highly complex, targeted attack against a DevOps engineer who was one of only four LastPass employees with access to the corporate vault.

“This was accomplished by targeting the DevOps engineer’s home computer and exploiting a vulnerable third-party media software package, which enabled remote code execution capability and allowed the threat actor to implant keylogger malware,” LastPass officials wrote. “The threat actor was able to capture the employee’s master password as it was entered, after the employee authenticated with MFA, and gain access to the DevOps engineer’s LastPass corporate vault.”

Dan Goodin at Ars Technica reported and then confirmed that the attackers exploited a known vulnerability in a Plex media server that the employee was running on his home network, and succeeded in installing malicious software that stole passwords and other authentication credentials. The vulnerability exploited by the intruders was patched back in 2020, but the employee never updated his Plex software.

As it happens, Plex announced its own data breach one day before LastPass disclosed its initial August intrusion. On August 24, 2022, Plex’s security team urged users to reset their passwords, saying an intruder had accessed customer emails, usernames and encrypted passwords.

OFFLINE ATTACKS

A basic functionality of LastPass is that it will pick and remember lengthy, complex passwords for each of your websites or online services. To automatically populate the appropriate credentials at any website going forward, you simply authenticate to LastPass using your master password.

LastPass has always emphasized that if you lose this master password, that’s too bad because they don’t store it and their encryption is so strong that even they can’t help you recover it.

But experts say all bets are off when cybercrooks can get their hands on the encrypted vault data itself — as opposed to having to interact with LastPass via its website. These so-called “offline” attacks allow the bad guys to conduct unlimited and unfettered “brute force” password cracking attempts against the encrypted data using powerful computers that can each try millions of password guesses per second.

“It does leave things vulnerable to brute force when the vaults are stolen en masse, especially if info about the vault HOLDER is available,” said Nicholas Weaver, a researcher at University of California, Berkeley’s International Computer Science Institute (ICSI) and lecturer at UC Davis. “So you just crunch and crunch and crunch with GPUs, with a priority list of vaults you target.”

How hard would it be for well-resourced criminals to crack the master passwords securing LastPass user vaults? Perhaps the best answer to this question comes from Wladimir Palant, a security researcher and the original developer behind the Adblock Plus browser plugin.

In a December 2022 blog post, Palant explained that the crackability of a LastPass master password depends largely on two things: The complexity of the master password, and the default settings for LastPass users, which appear to have varied quite a bit based on when those users began patronizing the service.

LastPass says that since 2018 it has required a twelve-character minimum for master passwords, which the company said “greatly minimizes the ability for successful brute force password guessing.”

But Palant said while LastPass indeed improved its master password defaults in 2018, it did not force all existing customers who had master passwords of lesser lengths to pick new credentials that would satisfy the 12-character minimum.

“If you are a LastPass customer, chances are that you are completely unaware of this requirement,” Palant wrote. “That’s because LastPass didn’t ask existing customers to change their master password. I had my test account since 2018, and even today I can log in with my eight-character password without any warnings or prompts to change it.”

Palant believes LastPass also failed to upgrade many older, original customers to more secure encryption protections that were offered to newer customers over the years. One important setting in LastPass is the number of “iterations,” or how many times your master password is run through the company’s encryption routines. The more iterations, the longer it takes an offline attacker to crack your master password.

Palant noted last year that for many older LastPass users, the initial default setting for iterations was anywhere from “1” to “500.” By 2013, new LastPass customers were given 5,000 iterations by default. In February 2018, LastPass changed the default to 100,100 iterations. And very recently, it upped that again to 600,000.

Palant said the 2018 change was in response to a security bug report he filed about some users having dangerously low iterations in their LastPass settings.

“Worse yet, for reasons that are beyond me, LastPass didn’t complete this migration,” Palant wrote. “My test account is still at 5,000 iterations, as are the accounts of many other users who checked their LastPass settings. LastPass would know how many users are affected, but they aren’t telling that. In fact, it’s painfully obvious that LastPass never bothered updating users’ security settings. Not when they changed the default from 1 to 500 iterations. Not when they changed it from 500 to 5,000. Only my persistence made them consider it for their latest change. And they still failed implementing it consistently.”

A chart on Palant’s blog post offers an idea of how increasing password iterations dramatically increases the costs and time needed by the attackers to crack someone’s master password. Palant said it would take a single GPU about a year to crack a password of average complexity with 500 iterations, and about 10 years to crack the same password run through 5,000 iterations.

However, these numbers radically come down when a determined adversary also has other large-scale computational assets at their disposal, such as a bitcoin mining operation that can coordinate the password-cracking activity across multiple powerful systems simultaneously.

Weaver said a password or passphrase with average complexity — such as “Correct Horse Battery Staple” is only secure against online attacks, and that its roughly 40 bits of randomness or “entropy” means a graphics card can blow through it in no time.

“An Nvidia 3090 can do roughly 4 million [password guesses] per second with 1000 iterations, but that would go down to 8 thousand per second with 500,000 iterations, which is why iteration count matters so much,” Weaver said. “So a combination of ‘not THAT strong of a password’ and ‘old vault’ and ‘low iteration count’ would make it theoretically crackable but real work, but the work is worth it given the targets.”

Reached by KrebsOnSecurity, Palant said he never received a response from LastPass about why the company apparently failed to migrate some number of customers to more secure account settings.

“I know exactly as much as everyone else,” Palant wrote in reply. “LastPass published some additional information in March. This finally answered the questions about the timeline of their breach – meaning which users are affected. It also made obvious that business customers are very much at risk here, Federated Login Services being highly compromised in this breach (LastPass downplaying as usual of course).”

Palant said upon logging into his LastPass account a few days ago, he found his master password was still set at 5,000 iterations.

INTERVIEW WITH A VICTIM

KrebsOnSecurity interviewed one of the victims tracked down by Monahan, a software engineer and startup founder who recently was robbed of approximately $3.4 million worth of different cryptocurrencies. The victim agreed to tell his story in exchange for anonymity because he is still trying to claw back his losses. We’ll refer to him here as “Connor” (not his real name).

Connor said he began using LastPass roughly a decade ago, and that he also stored the seed phrase for his primary cryptocurrency wallet inside of LastPass. Connor chose to protect his LastPass password vault with an eight character master password that included numbers and symbols (~50 bits of entropy).

“I thought at the time that the bigger risk was losing a piece of paper with my seed phrase on it,” Connor said. “I had it in a bank security deposit box before that, but then I started thinking, ‘Hey, the bank might close or burn down and I could lose my seed phrase.'”

Those seed phrases sat in his LastPass vault for years. Then, early on the morning of Sunday, Aug. 27, 2023, Connor was awoken by a service he’d set up to monitor his cryptocurrency addresses for any unusual activity: Someone was draining funds from his accounts, and fast.

Like other victims interviewed for this story, Connor didn’t suffer the usual indignities that typically presage a cryptocurrency robbery, such as account takeovers of his email inbox or mobile phone number.

Connor said he doesn’t know the number of iterations his master password was given originally, or what it was set at when the LastPass user vault data was stolen last year. But he said he recently logged into his LastPass account and the system forced him to upgrade to the new 600,000 iterations setting.

“Because I set up my LastPass account so early, I’m pretty sure I had whatever weak settings or iterations it originally had,” he said.

Connor said he’s kicking himself because he recently started the process of migrating his cryptocurrency to a new wallet protected by a new seed phrase. But he never finished that migration process. And then he got hacked.

“I’d set up a brand new wallet with new keys,” he said. “I had that ready to go two months ago, but have been procrastinating moving things to the new wallet.”

Connor has been exceedingly lucky in regaining access to some of his stolen millions in cryptocurrency. The Internet is swimming with con artists masquerading as legitimate cryptocurrency recovery experts. To make matters worse, because time is so critical in these crypto heists, many victims turn to the first quasi-believable expert who offers help.

Instead, several friends steered Connor to Flashbots.net, a cryptocurrency recovery firm that employs several custom techniques to help clients claw back stolen funds — particularly those on the Ethereum blockchain.

According to Connor, Flashbots helped rescue approximately $1.5 million worth of the $3.4 million in cryptocurrency value that was suddenly swept out of his account roughly a week ago. Lucky for him, Connor had some of his assets tied up in a type of digital loan that allowed him to borrow against his various cryptocurrency assets.

Without giving away too many details about how they clawed back the funds, here’s a high level summary: When the crooks who stole Connor’s seed phrase sought to extract value from these loans, they were borrowing the maximum amount of credit that he hadn’t already used. But Connor said that left open an avenue for some of that value to be recaptured, basically by repaying the loan in many small, rapid chunks.

WHAT SHOULD LASTPASS USERS DO?

According to MetaMask’s Monahan, users who stored any important passwords with LastPass — particularly those related to cryptocurrency accounts — should change those credentials immediately, and migrate any crypto holdings to new offline hardware wallets.

“Really the ONLY thing you need to read is this,” Monahan pleaded to her 70,000 followers on Twitter/X: “PLEASE DON’T KEEP ALL YOUR ASSETS IN A SINGLE KEY OR SECRET PHRASE FOR YEARS. THE END. Split up your assets. Get a hw [hardware] wallet. Migrate. Now.”

If you also had passwords tied to banking or retirement accounts, or even just important email accounts — now would be a good time to change those credentials as well.

I’ve never been comfortable recommending password managers, because I’ve never seriously used them myself. Something about putting all your eggs in one basket. Heck, I’m so old-fashioned that most of my important passwords are written down and tucked away in safe places.

But I recognize this antiquated approach to password management is not for everyone. Connor says he now uses 1Password, a competing password manager that recently earned the best overall marks from Wired and The New York Times.

1Password says that three things are needed to decrypt your information: The encrypted data itself, your account password, and your Secret Key. Only you know your account password, and your Secret Key is generated locally during setup.

“The two are combined on-device to encrypt your vault data and are never sent to 1Password,” explains a 1Password blog post ‘What If 1Password Gets Hacked?‘ “Only the encrypted vault data lives on our servers, so neither 1Password nor an attacker who somehow manages to guess or steal your account password would be able to access your vaults – or what’s inside them.

Weaver said that Secret Key adds an extra level of randomness to all user master passwords that LastPass didn’t have.

“With LastPass, the idea is the user’s password vault is encrypted with a cryptographic hash (H) of the user’s passphrase,” Weaver said. “The problem is a hash of the user’s passphrase is remarkably weak on older LastPass vaults with master passwords that do not have many iterations. 1Password uses H(random-key||password) to generate the password, and it is why you have the QR code business when adding a new device.”

Weaver said LastPass deserves blame for not having upgraded iteration counts for all users a long time ago, and called the latest forced upgrades “a stunning indictment of the negligence on the part of LastPass.”

“That they never even notified all those with iteration counts of less than 100,000 — who are really vulnerable to brute force even with 8-character random passwords or ‘correct horse battery staple’ type passphrases — is outright negligence,” Weaver said. “I would personally advocate that nobody ever uses LastPass again: Not because they were hacked. Not because they had an architecture (unlike 1Password) that makes such hacking a problem. But because of their consistent refusal to address how they screwed up and take proactive efforts to protect their customers.”

Bax and Monahan both acknowledged that their research alone can probably never conclusively tie dozens of high-dollar crypto heists over the past year to the LastPass breach. But Bax says at this point he doesn’t see any other possible explanation.

“Some might say it’s dangerous to assert a strong connection here, but I’d say it’s dangerous to assert there isn’t one,” he said. “I was arguing with my fiance about this last night. She’s waiting for LastPass to tell her to change everything. Meanwhile, I’m telling her to do it now.”

Glut of Fake LinkedIn Profiles Pits HR Against the Bots

A recent proliferation of phony executive profiles on LinkedIn is creating something of an identity crisis for the business networking site, and for companies that rely on it to hire and screen prospective employees. The fabricated LinkedIn identities — which pair AI-generated profile photos with text lifted from legitimate accounts — are creating major headaches for corporate HR departments and for those managing invite-only LinkedIn groups.

Last week, KrebsOnSecurity examined a flood of inauthentic LinkedIn profiles all claiming Chief Information Security Officer (CISO) roles at various Fortune 500 companies, including Biogen, Chevron, ExxonMobil, and Hewlett Packard.

Since then, the response from LinkedIn users and readers has made clear that these phony profiles are showing up en masse for virtually all executive roles — but particularly for jobs and industries that are adjacent to recent global events and news trends.

Hamish Taylor runs the Sustainability Professionals group on LinkedIn, which has more than 300,000 members. Together with the group’s co-owner, Taylor said they’ve blocked more than 12,700 suspected fake profiles so far this year, including dozens of recent accounts that Taylor describes as “cynical attempts to exploit Humanitarian Relief and Crisis Relief experts.”

“We receive over 500 fake profile requests to join on a weekly basis,” Taylor said. “It’s hit like hell since about January of this year. Prior to that we did not get the swarms of fakes that we now experience.”

Taylor recently posted an entry on LinkedIn titled, “The Fake ID Crisis on LinkedIn,” which lampooned the “60 Least Wanted ‘Crisis Relief Experts’ — fake profiles that claimed to be experts in disaster recovery efforts in the wake of recent hurricanes. The images above and below show just one such swarm of profiles the group flagged as inauthentic. Virtually all of these profiles were removed from LinkedIn after KrebsOnSecurity tweeted about them last week.

Mark Miller is the owner of the DevOps group on LinkedIn, and says he deals with fake profiles on a daily basis — often hundreds per day. What Taylor called “swarms” of fake accounts Miller described instead as “waves” of incoming requests from phony accounts.

“When a bot tries to infiltrate the group, it does so in waves,” Miller said. “We’ll see 20-30 requests come in with the same type of information in the profiles.”

After screenshotting the waves of suspected fake profile requests, Miller started sending the images to LinkedIn’s abuse teams, which told him they would review his request but that he may never be notified of any action taken.

Miller said that after months of complaining and sharing fake profile information with LinkedIn, the social media network appeared to do something which caused the volume of group membership requests from phony accounts to drop precipitously.

“I wrote our LinkedIn rep and said we were considering closing the group down the bots were so bad,” Miller said. “I said, ‘You guys should be doing something on the backend to block this.”

Jason Lathrop is vice president of technology and operations at ISOutsource, a Seattle-based consulting firm with roughly 100 employees. Like Miller, Lathrop’s experience in fighting bot profiles on LinkedIn suggests the social networking giant will eventually respond to complaints about inauthentic accounts. That is, if affected users complain loudly enough (posting about it publicly on LinkedIn seems to help).

Lathrop said that about two months ago his employer noticed waves of new followers, and identified more than 3,000 followers that all shared various elements, such as profile photos or text descriptions.

“Then I noticed that they all claim to work for us at some random title within the organization,” Lathrop said in an interview with KrebsOnSecurity. “When we complained to LinkedIn, they’d tell us these profiles didn’t violate their community guidelines. But like heck they don’t! These people don’t exist, and they’re claiming they work for us!”

Lathrop said that after his company’s third complaint, a LinkedIn representative responded by asking ISOutsource to send a spreadsheet listing every legitimate employee in the company, and their corresponding profile links.

Not long after that, the phony profiles that were not on the company’s list were deleted from LinkedIn. Lathrop said he’s still not sure how they’re going to handle getting new employees allowed into their company on LinkedIn going forward.

It remains unclear why LinkedIn has been flooded with so many fake profiles lately, or how the phony profile photos are sourced. Random testing of the profile photos shows they resemble but do not match other photos posted online. Several readers pointed out one likely source — the website thispersondoesnotexist.com, which makes using artificial intelligence to create unique headshots a point-and-click exercise.

Cybersecurity firm Mandiant (recently acquired by Google) told Bloomberg that hackers working for the North Korean government have been copying resumes and profiles from leading job listing platforms LinkedIn and Indeed, as part of an elaborate scheme to land jobs at cryptocurrency firms.

Fake profiles also may be tied to so-called “pig butchering” scams, 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.

In addition, identity thieves have been known to masquerade on LinkedIn as job recruiters, collecting personal and financial information from people who fall for employment scams.

But the Sustainability Group administrator Taylor said the bots he’s tracked strangely don’t respond to messages, nor do they appear to try to post content.

“Clearly they are not monitored,” Taylor assessed. “Or they’re just created and then left to fester.”

This experience was shared by the DevOp group admin Miller, who said he’s also tried baiting the phony profiles with messages referencing their fakeness. Miller says he’s worried someone is creating a massive social network of bots for some future attack in which the automated accounts may be used to amplify false information online, or at least muddle the truth.

“It’s almost like someone is setting up a huge bot network so that when there’s a big message that needs to go out they can just mass post with all these fake profiles,” Miller said.

In last week’s story on this topic, I suggested LinkedIn could take one simple step that would make it far easier for people to make informed decisions about whether to trust a given profile: Add a “created on” date for every profile. Twitter does this, and it’s enormously helpful for filtering out a great deal of noise and unwanted communications.

Many of our readers on Twitter said LinkedIn needs to give employers more tools — perhaps some kind of application programming interface (API) — that would allow them to quickly remove profiles that falsely claim to be employed at their organizations.

Another reader suggested LinkedIn also could experiment with offering something akin to Twitter’s verified mark to users who chose to validate that they can respond to email at the domain associated with their stated current employer.

In response to questions from KrebsOnSecurity, LinkedIn said it was considering the domain verification idea.

“This is an ongoing challenge and we’re constantly improving our systems to stop fakes before they come online,” LinkedIn said in a written statement. “We do stop the vast majority of fraudulent activity we detect in our community – around 96% of fake accounts and around 99.1% of spam and scams. We’re also exploring new ways to protect our members such as expanding email domain verification. Our community is all about authentic people having meaningful conversations and to always increase the legitimacy and quality of our community.”

In a story published Wednesday, Bloomberg noted that LinkedIn has largely so far avoided the scandals about bots that have plagued networks like Facebook and Twitter. But that shine is starting to come off, as more users are forced to waste more of their time fighting off inauthentic accounts.

“What’s clear is that LinkedIn’s cachet as being the social network for serious professionals makes it the perfect platform for lulling members into a false sense of security,” Bloomberg’s Tim Cuplan wrote. “Exacerbating the security risk is the vast amount of data that LinkedIn collates and publishes, and which underpins its whole business model but which lacks any robust verification mechanisms.”