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A number of Discord communities focused on cryptocurrency have been hacked this past month after their administrators were tricked into running malicious Javascript code disguised as a Web browser bookmark.
This attack involves malicious Javascript that is added to one’s browser by dragging a component from a web page to one’s browser bookmarks.
According to interviews with victims, several of the attacks began with an interview request from someone posing as a reporter for a crypto-focused news outlet online. Those who take the bait are sent a link to a Discord server that appears to be the official Discord of the crypto news site, where they are asked to complete a verification step to validate their identity.
As shown in this Youtube video, the verification process involves dragging a button from the phony crypto news Discord server to the bookmarks bar in one’s Web browser. From there, the visitor is instructed to go back to discord.com and then click the new bookmark to complete the verification process.
However, the bookmark is actually a clever snippet of Javascript that quietly grabs the user’s Discord token and sends it to the scammer’s website. The attacker then loads the stolen token into their own browser session and (usually late at night after the admins are asleep) posts an announcement in the targeted Discord about an exclusive “airdrop,” “NFT mint event” or some other potential money making opportunity for the Discord members.
The unsuspecting Discord members click the link provided by the compromised administrator account, and are asked to connect their crypto wallet to the scammer’s site, where it asks for unlimited spend approvals on their tokens, and subsequently drains the balance of any valuable accounts.
Meanwhile, anyone in the compromised Discord channel who notices the scam and replies is banned, and their messages are deleted by the compromised admin account.
Nicholas Scavuzzo is an associate at Ocean Protocol, which describes itself as an “open-source protocol that aims to allow businesses and individuals to exchange and monetize data and data-based services.” On May 22, an administrator for Ocean Protocol’s Discord server clicked a link in a direct message from a community member that prompted them to prove their identity by dragging a link to their bookmarks.
Scavuzzo, who is based in Maine, said the attackers waited until around midnight in his timezone time before using the administrator’s account to send out an unauthorized message about a new Ocean airdrop.
Scavuzzo said the administrator’s account was hijacked even though she had multi-factor authentication turned on.
“A CAPTCHA bot that allows Discord cookies to be accessed by the person hosting the CAPTCHA,” was how Scavuzzo described the attack. “I’ve seen all kinds of crypto scams, but I’ve never seen one like this.”
In this conversation, “Ana | Ocean” is a compromised Discord server administrator account promoting a phony airdrop.
Importantly, the stolen token only works for the attackers as long as its rightful owner doesn’t log out and back in, or else change their credentials.
Assuming the administrator can log in, that is. In Ocean’s case, one of the first things the intruders did once they swiped the administrator’s token was change the server’s access controls and remove all core Ocean team members from the server.
Fortunately for Ocean, Scavuzzo was able to reach the operator of the server that hosts the Discord channel, and have the channel’s settings reverted back to normal.
“Thankfully, we are a globally distributed team, so we have people awake at all hours,” Scavuzzo said, noting that Ocean is not aware of any Discord community members who fell for the phony airdrop offer, which was live for about 30 minutes. “This could have been a lot worse.”
On May 26, Aura Network reported on Twitter that its Discord server was compromised in a phishing attack that resulted in the deletion of Discord channels and the dissemination of fake Aura Network Airdrop Campaign links.
On May 27, Nahmii — a cryptocurrency technology based on the Ethereum blockchain — warned on Twitter that one of its community moderators on Discord was compromised and posting fake airdrop details.
On May 9, MetrixCoin reported that its Discord server was hacked, with fake airdrop details pushed to all users.
KrebsOnSecurity recently heard from a trusted source in the cybersecurity industry who dealt firsthand with one of these attacks and asked to remain anonymous.
“I do pro bono Discord security work for a few Discords, and I was approached by one of these fake journalists,” the source said. “I played along and got the link to their Discord, where they were pretending to be journalists from the Cryptonews website using several accounts.”
The source took note of all the Discord IDs of the admins of the fake Cryptonews Discord, so that he could ensure they were blocked from the Discords he helps to secure.
“Since I’ve been doing this for a while now, I’ve built up a substantial database of Discord users and messages, so often I can see these scammers’ history on Discord,” the source said.
In this case, he noticed a user with the “CEO” role in the fake Cryptonews Discord had been seen previously under another username — “Levatax.” Searching on that Discord ID and username revealed a young Turkish coder named Berk Yilmaz whose Github page linked to the very same Discord ID as the scammer CEO.
Reached via instant message on Telegram, Levatax said he’s had no involvement in such schemes, and that he hasn’t been on Discord since his Microsoft Outlook account was hacked months ago.
“The interesting thing [is] that I didn’t use Discord since few months or even social media because of the political status of Turkey,” Levatax explained, referring to the recent election in his country. “The only thing I confirm is losing my Outlook account which connected to my Discord, and I’m already in touch with Microsoft to recover it.”
The verification method used in the above scam involves a type of bookmark called a “bookmarklet” that stores Javascript code as a clickable link in the bookmarks bar at the top of one’s browser.
While bookmarklets can be useful and harmless, malicious Javascript that is executed in the browser by the user is especially dangerous. So please avoid adding (or dragging) any bookmarks or bookmarklets to your browser unless it was your idea in the first place.
Peter is an IT manager for a technology manufacturer that got hit with a Russian ransomware strain called “Zeppelin” in May 2020. He’d been on the job less than six months, and because of the way his predecessor architected things, the company’s data backups also were encrypted by Zeppelin. After two weeks of stalling their extortionists, Peter’s bosses were ready to capitulate and pay the ransom demand. Then came the unlikely call from an FBI agent. “Don’t pay,” the agent said. “We’ve found someone who can crack the encryption.”
Peter, who spoke candidly about the attack on condition of anonymity, said the FBI told him to contact a cybersecurity consulting firm in New Jersey called Unit 221B, and specifically its founder — Lance James. Zeppelin sprang onto the crimeware scene in December 2019, but it wasn’t long before James discovered multiple vulnerabilities in the malware’s encryption routines that allowed him to brute-force the decryption keys in a matter of hours, using nearly 100 cloud computer servers.
In an interview with KrebsOnSecurity, James said Unit 221B was wary of advertising its ability to crack Zeppelin ransomware keys because it didn’t want to tip its hand to Zeppelin’s creators, who were likely to modify their file encryption approach if they detected it was somehow being bypassed.
This is not an idle concern. There are multiple examples of ransomware groups doing just that after security researchers crowed about finding vulnerabilities in their ransomware code.
“The minute you announce you’ve got a decryptor for some ransomware, they change up the code,” James said.
But he said the Zeppelin group appears to have stopped spreading their ransomware code gradually over the past year, possibly because Unit 221B’s referrals from the FBI let them quietly help nearly two dozen victim organizations recover without paying their extortionists.
In a blog post published today to coincide with a Black Hat talk on their discoveries, James and co-author Joel Lathrop said they were motivated to crack Zeppelin after the ransomware gang started attacking nonprofit and charity organizations.
“What motivated us the most during the leadup to our action was the targeting of homeless shelters, nonprofits and charity organizations,” the two wrote. “These senseless acts of targeting those who are unable to respond are the motivation for this research, analysis, tools, and blog post. A general Unit 221B rule of thumb around our offices is: Don’t [REDACTED] with the homeless or sick! It will simply trigger our ADHD and we will get into that hyper-focus mode that is good if you’re a good guy, but not so great if you are an ***hole.”
The researchers said their break came when they understood that while Zeppelin used three different types of encryption keys to encrypt files, they could undo the whole scheme by factoring or computing just one of them: An ephemeral RSA-512 public key that is randomly generated on each machine it infects.
“If we can recover the RSA-512 Public Key from the registry, we can crack it and get the 256-bit AES Key that encrypts the files!” they wrote. “The challenge was that they delete the [public key] once the files are fully encrypted. Memory analysis gave us about a 5-minute window after files were encrypted to retrieve this public key.”
Unit 221B ultimately built a “Live CD” version of Linux that victims could run on infected systems to extract that RSA-512 key. From there, they would load the keys into a cluster of 800 CPUs donated by hosting giant Digital Ocean that would then start cracking them. The company also used that same donated infrastructure to help victims decrypt their data using the recovered keys.
A typical Zeppelin ransomware note.
Jon is another grateful Zeppelin ransomware victim who was aided by Unit 221B’s decryption efforts. Like Peter, Jon asked that his last name and that of his employer be omitted from the story, but he’s in charge of IT for a mid-sized managed service provider that got hit with Zeppelin in July 2020.
The attackers that savaged Jon’s company managed to phish credentials and a multi-factor authentication token for some tools the company used to support customers, and in short order they’d seized control over the servers and backups for a healthcare provider customer.
Jon said his company was reluctant to pay a ransom in part because it wasn’t clear from the hackers’ demands whether the ransom amount they demanded would provide a key to unlock all systems, and that it would do so safely.
“They want you to unlock your data with their software, but you can’t trust that,” Jon said. “You want to use your own software or someone else who’s trusted to do it.”
In August 2022, the FBI and the Cybersecurity & Infrastructure Security Agency (CISA) issued a joint warning on Zeppelin, saying the FBI had “observed instances where Zeppelin actors executed their malware multiple times within a victim’s network, resulting in the creation of different IDs or file extensions, for each instance of an attack; this results in the victim needing several unique decryption keys.”
The advisory says Zeppelin has attacked “a range of businesses and critical infrastructure organizations, including defense contractors, educational institutions, manufacturers, technology companies, and especially organizations in the healthcare and medical industries. Zeppelin actors have been known to request ransom payments in Bitcoin, with initial amounts ranging from several thousand dollars to over a million dollars.”
The FBI and CISA say the Zeppelin actors gain access to victim networks by exploiting weak Remote Desktop Protocol (RDP) credentials, exploiting SonicWall firewall vulnerabilities, and phishing campaigns. Prior to deploying Zeppelin ransomware, actors spend one to two weeks mapping or enumerating the victim network to identify data enclaves, including cloud storage and network backups, the alert notes.
Jon said he felt so lucky after connecting with James and hearing about their decryption work, that he toyed with the idea of buying a lottery ticket that day.
“This just doesn’t usually happen,” Jon said. “It’s 100 percent like winning the lottery.”
By the time Jon’s company got around to decrypting their data, they were forced by regulators to prove that no patient data had been exfiltrated from their systems. All told, it took his employer two months to fully recover from the attack.
“I definitely feel like I was ill-prepared for this attack,” Jon said. “One of the things I’ve learned from this is the importance of forming your core team and having those people who know what their roles and responsibilities are ahead of time. Also, trying to vet new vendors you’ve never met before and build trust relationships with them is very difficult to do when you have customers down hard now and they’re waiting on you to help them get back up.”
A more technical writeup on Unit 221B’s discoveries (cheekily titled “0XDEAD ZEPPELIN”) is available here.
Phishers are enjoying remarkable success using text messages to steal remote access credentials and one-time passcodes from employees at some of the world’s largest technology companies and customer support firms. A recent spate of SMS phishing attacks from one cybercriminal group has spawned a flurry of breach disclosures from affected companies, which are all struggling to combat the same lingering security threat: The ability of scammers to interact directly with employees through their mobile devices.
In mid-June 2022, a flood of SMS phishing messages began targeting employees at commercial staffing firms that provide customer support and outsourcing to thousands of companies. The missives asked users to click a link and log in at a phishing page that mimicked their employer’s Okta authentication page. Those who submitted credentials were then prompted to provide the one-time password needed for multi-factor authentication.
The phishers behind this scheme used newly-registered domains that often included the name of the target company, and sent text messages urging employees to click on links to these domains to view information about a pending change in their work schedule.
The phishing sites leveraged a Telegram instant message bot to forward any submitted credentials in real-time, allowing the attackers to use the phished username, password and one-time code to log in as that employee at the real employer website. But because of the way the bot was configured, it was possible for security researchers to capture the information being sent by victims to the public Telegram server.
This data trove was first reported by security researchers at Singapore-based Group-IB, which dubbed the campaign “0ktapus” for the attackers targeting organizations using identity management tools from Okta.com.
“This case is of interest because despite using low-skill methods it was able to compromise a large number of well-known organizations,” Group-IB wrote. “Furthermore, once the attackers compromised an organization they were quickly able to pivot and launch subsequent supply chain attacks, indicating that the attack was planned carefully in advance.”
It’s not clear how many of these phishing text messages were sent out, but the Telegram bot data reviewed by KrebsOnSecurity shows they generated nearly 10,000 replies over approximately two months of sporadic SMS phishing attacks targeting more than a hundred companies.
A great many responses came from those who were apparently wise to the scheme, as evidenced by the hundreds of hostile replies that included profanity or insults aimed at the phishers: The very first reply recorded in the Telegram bot data came from one such employee, who responded with the username “havefuninjail.”
Still, thousands replied with what appear to be legitimate credentials — many of them including one-time codes needed for multi-factor authentication. On July 20, the attackers turned their sights on internet infrastructure giant Cloudflare.com, and the intercepted credentials show at least three employees fell for the scam.
Image: Cloudflare.com
In a blog post earlier this month, Cloudflare said it detected the account takeovers and that no Cloudflare systems were compromised. Cloudflare said it does not rely on one-time passcodes as a second factor, so there was nothing to provide to the attackers. But Cloudflare said it wanted to call attention to the phishing attacks because they would probably work against most other companies.
“This was a sophisticated attack targeting employees and systems in such a way that we believe most organizations would be likely to be breached,” Cloudflare CEO Matthew Prince wrote. “On July 20, 2022, the Cloudflare Security team received reports of employees receiving legitimate-looking text messages pointing to what appeared to be a Cloudflare Okta login page. The messages began at 2022-07-20 22:50 UTC. Over the course of less than 1 minute, at least 76 employees received text messages on their personal and work phones. Some messages were also sent to the employees family members.”
On three separate occasions, the phishers targeted employees at Twilio.com, a San Francisco based company that provides services for making and receiving text messages and phone calls. It’s unclear how many Twilio employees received the SMS phishes, but the data suggest at least four Twilio employees responded to a spate of SMS phishing attempts on July 27, Aug. 2, and Aug. 7.
On that last date, Twilio disclosed that on Aug. 4 it became aware of unauthorized access to information related to a limited number of Twilio customer accounts through a sophisticated social engineering attack designed to steal employee credentials.
“This broad based attack against our employee base succeeded in fooling some employees into providing their credentials,” Twilio said. “The attackers then used the stolen credentials to gain access to some of our internal systems, where they were able to access certain customer data.”
That “certain customer data” included information on roughly 1,900 users of the secure messaging app Signal, which relied on Twilio to provide phone number verification services. In its disclosure on the incident, Signal said that with their access to Twilio’s internal tools the attackers were able to re-register those users’ phone numbers to another device.
On Aug. 25, food delivery service DoorDash disclosed that a “sophisticated phishing attack” on a third-party vendor allowed attackers to gain access to some of DoorDash’s internal company tools. DoorDash said intruders stole information on a “small percentage” of users that have since been notified. TechCrunch reported last week that the incident was linked to the same phishing campaign that targeted Twilio.
This phishing gang apparently had great success targeting employees of all the major mobile wireless providers, but most especially T-Mobile. Between July 10 and July 16, dozens of T-Mobile employees fell for the phishing messages and provided their remote access credentials.
“Credential theft continues to be an ongoing issue in our industry as wireless providers are constantly battling bad actors that are focused on finding new ways to pursue illegal activities like this,” T-Mobile said in a statement. “Our tools and teams worked as designed to quickly identify and respond to this large-scale smishing attack earlier this year that targeted many companies. We continue to work to prevent these types of attacks and will continue to evolve and improve our approach.”
This same group saw hundreds of responses from employees at some of the largest customer support and staffing firms, including Teleperformanceusa.com, Sitel.com and Sykes.com. Teleperformance did not respond to requests for comment. KrebsOnSecurity did hear from Christopher Knauer, global chief security officer at Sitel Group, the customer support giant that recently acquired Sykes. Knauer said the attacks leveraged newly-registered domains and asked employees to approve upcoming changes to their work schedules.
Image: Group-IB.
Knauer said the attackers set up the phishing domains just minutes in advance of spamming links to those domains in phony SMS alerts to targeted employees. He said such tactics largely sidestep automated alerts generated by companies that monitor brand names for signs of new phishing domains being registered.
“They were using the domains as soon as they became available,” Knauer said. “The alerting services don’t often let you know until 24 hours after a domain has been registered.”
On July 28 and again on Aug. 7, several employees at email delivery firm Mailchimp provided their remote access credentials to this phishing group. According to an Aug. 12 blog post, the attackers used their access to Mailchimp employee accounts to steal data from 214 customers involved in cryptocurrency and finance.
On Aug. 15, the hosting company DigitalOcean published a blog post saying it had severed ties with MailChimp after its Mailchimp account was compromised. DigitalOcean said the MailChimp incident resulted in a “very small number” of DigitalOcean customers experiencing attempted compromises of their accounts through password resets.
According to interviews with multiple companies hit by the group, the attackers are mostly interested in stealing access to cryptocurrency, and to companies that manage communications with people interested in cryptocurrency investing. In an Aug. 3 blog post from email and SMS marketing firm Klaviyo.com, the company’s CEO recounted how the phishers gained access to the company’s internal tools, and used that to download information on 38 crypto-related accounts.
A flow chart of the attacks by the SMS phishing group known as 0ktapus and ScatterSwine. Image: Amitai Cohen for Wiz.io. twitter.com/amitaico.
The ubiquity of mobile phones became a lifeline for many companies trying to manage their remote employees throughout the Coronavirus pandemic. But these same mobile devices are fast becoming a liability for organizations that use them for phishable forms of multi-factor authentication, such as one-time codes generated by a mobile app or delivered via SMS.
Because as we can see from the success of this phishing group, this type of data extraction is now being massively automated, and employee authentication compromises can quickly lead to security and privacy risks for the employer’s partners or for anyone in their supply chain.
Unfortunately, a great many companies still rely on SMS for employee multi-factor authentication. According to a report this year from Okta, 47 percent of workforce customers deploy SMS and voice factors for multi-factor authentication. That’s down from 53 percent that did so in 2018, Okta found.
Some companies (like Knauer’s Sitel) have taken to requiring that all remote access to internal networks be managed through work-issued laptops and/or mobile devices, which are loaded with custom profiles that can’t be accessed through other devices.
Others are moving away from SMS and one-time code apps and toward requiring employees to use physical FIDO multi-factor authentication devices such as security keys, which can neutralize phishing attacks because any stolen credentials can’t be used unless the phishers also have physical access to the user’s security key or mobile device.
This came in handy for Twitter, which announced last year that it was moving all of its employees to using security keys, and/or biometric authentication via their mobile device. The phishers’ Telegram bot reported that on June 16, 2022, five employees at Twitter gave away their work credentials. In response to questions from KrebsOnSecurity, Twitter confirmed several employees were relieved of their employee usernames and passwords, but that its security key requirement prevented the phishers from abusing that information.
Twitter accelerated its plans to improve employee authentication following the July 2020 security incident, wherein several employees were phished and relieved of credentials for Twitter’s internal tools. In that intrusion, the attackers used Twitter’s tools to hijack accounts for some of the world’s most recognizable public figures, executives and celebrities — forcing those accounts to tweet out links to bitcoin scams.
“Security keys can differentiate legitimate sites from malicious ones and block phishing attempts that SMS 2FA or one-time password (OTP) verification codes would not,” Twitter said in an Oct. 2021 post about the change. “To deploy security keys internally at Twitter, we migrated from a variety of phishable 2FA methods to using security keys as our only supported 2FA method on internal systems.”
Update, 6:02 p.m. ET: Clarified that Cloudflare does not rely on TOTP (one-time multi-factor authentication codes) as a second factor for employee authentication.
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