Twitter’s Clumsy Pivot to X.com Is a Gift to Phishers

On April 9, Twitter/X began automatically modifying links that mention “twitter.com” to read “x.com” instead. But over the past 48 hours, dozens of new domain names have been registered that demonstrate how this change could be used to craft convincing phishing links — such as fedetwitter[.]com, which until very recently rendered as fedex.com in tweets.

A search at DomainTools.com shows at least 60 domain names have been registered over the past two days for domains ending in “twitter.com,” although research so far shows the majority of these domains have been registered “defensively” by private individuals to prevent the domains from being purchased by scammers.

Those include carfatwitter.com, which Twitter/X truncated to carfax.com when the domain appeared in user messages or tweets. Visiting this domain currently displays a message that begins, “Are you serious, X Corp?”

Update: It appears Twitter/X has corrected its mistake, and no longer truncates any domain ending in “twitter.com” to “x.com.”

Original story:

The same message is on other newly registered domains, including goodrtwitter.com (goodrx.com), neobutwitter.com (neobux.com), roblotwitter.com (roblox.com), square-enitwitter.com (square-enix.com) and yandetwitter.com (yandex.com). The message left on these domains indicates they were defensively registered by a user on Mastodon whose bio says they are a systems admin/engineer. That profile has not responded to requests for comment.

A number of these new domains including “twitter.com” appear to be registered defensively by Twitter/X users in Japan. The domain netflitwitter.com (netflix.com, to Twitter/X users) now displays a message saying it was “acquired to prevent its use for malicious purposes,” along with a Twitter/X username.

The domain mentioned at the beginning of this story — fedetwitter.com — redirects users to the blog of a Japanese technology enthusiast. A user with the handle “amplest0e” appears to have registered space-twitter.com, which Twitter/X users would see as the CEO’s “space-x.com.” The domain “ametwitter.com” already redirects to the real americanexpress.com.

Some of the domains registered recently and ending in “twitter.com” currently do not resolve and contain no useful contact information in their registration records. Those include firefotwitter[.]com (firefox.com), ngintwitter[.]com (nginx.com), and webetwitter[.]com (webex.com).

Sean McNee, vice president of research and data at DomainTools, told KrebsOnSecurity it appears Twitter/X did not properly limit its redirection efforts.

“Bad actors could register domains as a way to divert traffic from legitimate sites or brands given the opportunity — many such brands in the top million domains end in x, such as webex, hbomax, xerox, xbox, and more,” McNee said. “It is also notable that several other globally popular brands, such as Rolex and Linux, were also on the list of registered domains.”

The apparent oversight by Twitter/X was cause for amusement and amazement from many former users who have migrated to other social media platforms since the new CEO took over. Matthew Garrett, a lecturer at U.C. Berkeley’s School of Information, summed up the Schadenfreude thusly:

“Twitter just doing a ‘redirect links in tweets that go to x.com to twitter.com instead but accidentally do so for all domains that end x.com like eg spacex.com going to spacetwitter.com’ is not absolutely the funniest thing I could imagine but it’s high up there.”

U.K. Cyber Thug “PlugwalkJoe” Gets 5 Years in Prison

Joseph James “PlugwalkJoe” O’Connor, a 24-year-old from the United Kingdom who earned his 15 minutes of fame by participating in the July 2020 hack of Twitter, has been sentenced to five years in a U.S. prison. That may seem like harsh punishment for a brief and very public cyber joy ride. But O’Connor also pleaded guilty in a separate investigation involving a years-long spree of cyberstalking and cryptocurrency theft enabled by “SIM swapping,” a crime wherein fraudsters trick a mobile provider into diverting a customer’s phone calls and text messages to a device they control.

On July 16, 2020 — the day after some of Twitter’s most recognizable and popular users had their accounts hacked and used to tweet out a bitcoin scam —  KrebsOnSecurity observed that several social media accounts tied to O’Connor appeared to have inside knowledge of the intrusion. That story also noted that thanks to COVID-19 lockdowns at the time, O’Connor was stuck on an indefinite vacation at a popular resort in Spain.

Not long after the Twitter hack, O’Connor was quoted in The New York Times denying any involvement. “I don’t care,” O’Connor told The Times. “They can come arrest me. I would laugh at them. I haven’t done anything.”

Speaking with KrebsOnSecurity via Instagram instant message just days after the Twitter hack, PlugwalkJoe demanded that his real name be kept out of future blog posts here. After he was told that couldn’t be promised, he remarked that some people in his circle of friends had been known to hire others to deliver physical beatings on people they didn’t like.

O’Connor was still in Spain a year later when prosecutors in the Northern District of California charged him with conspiring to hack Twitter. At the same time, prosecutors in the Southern District of New York charged O’Connor with an impressive array of cyber offenses involving the exploitation of social media accounts, online extortion, cyberstalking, and the theft of cryptocurrency then valued at nearly USD $800,000.

In late April 2023, O’Connor was extradited from Spain to face charges in the United States. Two weeks later, he entered guilty pleas in both California and New York, admitting to all ten criminal charges levied against him. On June 23, O’Connor was sentenced to five years in prison.

PlugwalkJoe was part of a community that specialized in SIM-swapping victims to take over their online identities. Unauthorized SIM swapping is a scheme in which fraudsters trick or bribe employees at wireless phone companies into redirecting the target’s text messages and phone calls to a device they control.

From there, the attackers can reset the password for any of the victim’s online accounts that allow password resets via SMS. SIM swapping also lets attackers intercept one-time passwords needed for SMS-based multi-factor authentication (MFA).

O’Connor admitted to conducting SIM swapping attacks to take control over financial accounts tied to several cryptocurrency executives in May 2019, and to stealing digital currency currently valued at more than $1.6 million.

PlugwalkJoe also copped to SIM-swapping his way into the Snapchat accounts of several female celebrities and threatening to release nude photos found on their phones.

Victims who refused to give up social media accounts or submit to extortion demands were often visited with “swatting attacks,” wherein O’Connor and others would falsely report a shooting or hostage situation in the hopes of tricking police into visiting potentially lethal force on a target’s address.

Prosecutors said O’Connor even swatted and cyberstalked a 16-year-old girl, sending her nude photos and threatening to rape and/or murder her and her family.

In the case of the Twitter hack, O’Connor pleaded guilty to conspiracy to commit computer intrusions, conspiracy to commit wire fraud, and conspiracy to commit money laundering.

To resolve the case against him in New York, O’Connor pleaded guilty to conspiracy to commit computer intrusion, two counts of committing computer intrusions, making extortive communications, two counts of stalking, and making threatening communications.

In addition to the prison term, O’Connor was sentenced to three years of supervised release, and ordered to pay $794,012.64 in forfeiture.

To be clear, the Twitter hack of July 2020 did not involve SIM-swapping. Rather, Twitter said the intruders tricked a Twitter employee over the phone into providing access to internal tools.

Three others were charged along with O’Connor in the Twitter compromise. The alleged mastermind of the hack, then 17-year-old Graham Ivan Clarke from Tampa, Fla., pleaded guilty in 2021 and agreed to serve three years in prison, followed by three years probation.

This story is good reminder about the need to minimize your reliance on the mobile phone companies for securing your online identity. This means reducing the number of ways your life could be turned upside down if someone were to hijack your mobile phone number.

Most online services require users to validate a mobile phone number as part of setting up an account, but some services will let you remove your phone number after the fact. Those services that do you let you remove your phone number or disable SMS/phone calls for account recovery probably also offer more secure multi-factor authentication options, such as app-based one-time passwords and security keys. Check out 2fa.directory for a list of multi-factor options available across hundreds of popular sites and services.

Interview With a Crypto Scam Investment Spammer

Social networks are constantly battling inauthentic bot accounts that send direct messages to users promoting scam cryptocurrency investment platforms. What follows is an interview with a Russian hacker responsible for a series of aggressive crypto spam campaigns that recently prompted several large Mastodon communities to temporarily halt new registrations. According to the hacker, their spam software has been in private use until the last few weeks, when it was released as open source code.

Renaud Chaput is a freelance programmer working on modernizing and scaling the Mastodon project infrastructure — including joinmastodon.org, mastodon.online, and mastodon.social. Chaput said that on May 4, 2023, someone unleashed a spam torrent targeting users on these Mastodon communities via “private mentions,” a kind of direct messaging on the platform.

The messages said recipients had earned an investment credit at a cryptocurrency trading platform called moonxtrade[.]com. Chaput said the spammers used more than 1,500 Internet addresses across 400 providers to register new accounts, which then followed popular accounts on Mastodon and sent private mentions to the followers of those accounts.

Since then, the same spammers have used this method to advertise more than 100 different crypto investment-themed domains. Chaput said that at one point this month the volume of bot accounts being registered for the crypto spam campaign started overwhelming the servers that handle new signups at Mastodon.social.

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

Seeking to gain a temporary handle on the spam wave, Chaput said he briefly disabled new account registrations on mastodon.social and mastondon.online. Shortly after that, those same servers came under a sustained distributed denial-of-service (DDoS) attack.

Chaput said whoever was behind the DDoS was definitely not using point-and-click DDoS tools, like a booter or stresser service.

“This was three hours non-stop, 200,000 to 400,000 requests per second,” Chaput said of the DDoS. “At first, they were targeting one path, and when we blocked that they started to randomize things. Over three hours the attack evolved several times.”

Chaput says the spam waves have died down since they retrofitted mastodon.social with a CAPTCHA, those squiggly letter and number combinations designed to stymie automated account creation tools. But he’s worried that other Mastodon instances may not be as well-staffed and might be easy prey for these spammers.

“We don’t know if this is the work of one person, or if this is [related to] software or services being sold to others,” Chaput told KrebsOnSecurity. “We’re really impressed by the scale of it — using hundreds of domains and thousands of Microsoft email addresses.”

Chaput said a review of their logs indicates many of the newly registered Mastodon spam accounts were registered using the same 0auth credentials, and that a domain common to those credentials was quot[.]pw.

A DIRECT QUOT

The domain quot[.]pw has been registered and abandoned by several parties since 2014, but the most recent registration data available through DomainTools.com shows it was registered in March 2020 to someone in Krasnodar, Russia with the email address edgard011012@gmail.com.

This email address is also connected to accounts on several Russian cybercrime forums, including “__edman__,” who had a history of selling “logs” — large amounts of data stolen from many bot-infected computers — as well as giving away access to hacked Internet of Things (IoT) devices.

In September 2018, a user by the name “ципа” (phonetically “Zipper” in Russian) registered on the Russian hacking forum Lolzteam using the edgard0111012@gmail.com address. In May 2020, Zipper told another Lolzteam member that quot[.]pw was their domain. That user advertised a service called “Quot Project” which said they could be hired to write programming scripts in Python and C++.

“I make Telegram bots and other rubbish cheaply,” reads one February 2020 sales thread from Zipper.

Clicking the “open chat in Telegram” button on Zipper’s Lolzteam profile page launched a Telegram instant message chat window where the user Quotpw responded almost immediately. Asked if they were aware their domain was being used to manage a spam botnet that was pelting Mastodon instances with crypto scam spam, Quotpw confirmed the spam was powered by their software.

“It was made for a limited circle of people,” Quotpw said, noting that they recently released the bot software as open source on GitHub.

Quotpw went on to say the spam botnet was powered by well more than the hundreds of IP addresses tracked by Chaput, and that these systems were mostly residential proxies. A residential proxy generally refers to a computer or mobile device running some type of software that enables the system to be used as a pass-through for Internet traffic from others.

Very often, this proxy software is installed surreptitiously, such as through a “Free VPN” service or mobile app. Residential proxies also can refer to households protected by compromised home routers running factory-default credentials or outdated firmware.

Quotpw maintains they have earned more than $2,000 sending roughly 100,000 private mentions to users of different Mastodon communities over the past few weeks. Quotpw said their conversion rate for the same bot-powered direct message spam on Twitter is usually much higher and more profitable, although they conceded that recent adjustments to Twitter’s anti-bot CAPTCHA have put a crimp in their Twitter earnings.

“My partners (I’m programmer) lost time and money while ArkoseLabs (funcaptcha) introduced new precautions on Twitter,” Quotpw wrote in a Telegram reply. “On Twitter, more spam and crypto scam.”

Asked whether they felt at all conflicted about spamming people with invitations to cryptocurrency scams, Quotpw said in their hometown “they pay more for such work than in ‘white’ jobs” — referring to legitimate programming jobs that don’t involve malware, botnets, spams and scams.

“Consider salaries in Russia,” Quotpw said. “Any spam is made for profit and brings illegal money to spammers.”

THE VIENNA CONNECTION

Shortly after edgard011012@gmail.com registered quot[.]pw, the WHOIS registration records for the domain were changed again, to msr-sergey2015@yandex.ru, and to a phone number in Austria: +43.6607003748.

Constella Intelligence, a company that tracks breached data, finds that the address msr-sergey2015@yandex.ru has been associated with accounts at the mobile app site aptoide.com (user: CoolappsforAndroid) and vimeworld.ru that were created from different Internet addresses in Vienna, Austria.

A search in Skype on that Austrian phone number shows it belongs to a Sergey Proshutinskiy who lists his location as Vienna, Austria. The very first result that comes up when one searches that unusual name in Google is a LinkedIn profile for a Sergey Proshutinskiy from Vienna, Austria.

Proshutinskiy’s LinkedIn profile says he is a Class of 2024 student at TGM, which is a state-owned, technical and engineering school in Austria. His resume also says he is a data science intern at Mondi Group, an Austrian manufacturer of sustainable packaging and paper.

Mr. Proshutinskiy did not respond to requests for comment.

Quotpw denied being Sergey, and said Sergey was a friend who registered the domain as a birthday present and favor last year.

“Initially, I bought it for 300 rubles,” Quotpw explained. “The extension cost 1300 rubles (expensive). I waited until it expired and forgot to buy it. After that, a friend (Sergey) bought [the] domain and transferred access rights to me.”

“He’s not even an information security specialist,” Quotpw said of Sergey. “My friends do not belong to this field. None of my friends are engaged in scams or other black [hat] activities.”

It may seem unlikely that someone would go to all this trouble to spam Mastodon users over several weeks using an impressive number of resources — all for just $2,000 in profit. But it is likely that whoever is actually running the various crypto scam platforms advertised by Quotpw’s spam messages pays handsomely for any investments generated by their spam.

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

Update, May 25, 10:30 a.m.:  Corrected attribution of the Austrian school TGM.

How 1-Time Passcodes Became a Corporate Liability

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.

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.

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.

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.