Login
Several Apple customers recently reported being targeted in elaborate phishing attacks that involve what appears to be a bug in Apple’s password reset feature. In this scenario, a target’s Apple devices are forced to display dozens of system-level prompts that prevent the devices from being used until the recipient responds “Allow” or “Don’t Allow” to each prompt. Assuming the user manages not to fat-finger the wrong button on the umpteenth password reset request, the scammers will then call the victim while spoofing Apple support in the caller ID, saying the user’s account is under attack and that Apple support needs to “verify” a one-time code.
Some of the many notifications Patel says he received from Apple all at once.
Parth Patel is an entrepreneur who is trying to build a startup in the conversational AI space. On March 23, Patel documented on Twitter/X a recent phishing campaign targeting him that involved what’s known as a “push bombing” or “MFA fatigue” attack, wherein the phishers abuse a feature or weakness of a multi-factor authentication (MFA) system in a way that inundates the target’s device(s) with alerts to approve a password change or login.
“All of my devices started blowing up, my watch, laptop and phone,” Patel told KrebsOnSecurity. “It was like this system notification from Apple to approve [a reset of the account password], but I couldn’t do anything else with my phone. I had to go through and decline like 100-plus notifications.”
Some people confronted with such a deluge may eventually click “Allow” to the incessant password reset prompts — just so they can use their phone again. Others may inadvertently approve one of these prompts, which will also appear on a user’s Apple watch if they have one.
But the attackers in this campaign had an ace up their sleeves: Patel said after denying all of the password reset prompts from Apple, he received a call on his iPhone that said it was from Apple Support (the number displayed was 1-800-275-2273, Apple’s real customer support line).
“I pick up the phone and I’m super suspicious,” Patel recalled. “So I ask them if they can verify some information about me, and after hearing some aggressive typing on his end he gives me all this information about me and it’s totally accurate.”
All of it, that is, except his real name. Patel said when he asked the fake Apple support rep to validate the name they had on file for the Apple account, the caller gave a name that was not his but rather one that Patel has only seen in background reports about him that are for sale at a people-search website called PeopleDataLabs.
Patel said he has worked fairly hard to remove his information from multiple people-search websites, and he found PeopleDataLabs uniquely and consistently listed this inaccurate name as an alias on his consumer profile.
“For some reason, PeopleDataLabs has three profiles that come up when you search for my info, and two of them are mine but one is an elementary school teacher from the midwest,” Patel said. “I asked them to verify my name and they said Anthony.”
Patel said the goal of the voice phishers is to trigger an Apple ID reset code to be sent to the user’s device, which is a text message that includes a one-time password. If the user supplies that one-time code, the attackers can then reset the password on the account and lock the user out. They can also then remotely wipe all of the user’s Apple devices.
Chris is a cryptocurrency hedge fund owner who asked that only his first name be used so as not to paint a bigger target on himself. Chris told KrebsOnSecurity he experienced a remarkably similar phishing attempt in late February.
“The first alert I got I hit ‘Don’t Allow’, but then right after that I got like 30 more notifications in a row,” Chris said. “I figured maybe I sat on my phone weird, or was accidentally pushing some button that was causing these, and so I just denied them all.”
Chris says the attackers persisted hitting his devices with the reset notifications for several days after that, and at one point he received a call on his iPhone that said it was from Apple support.
“I said I would call them back and hung up,” Chris said, demonstrating the proper response to such unbidden solicitations. “When I called back to the real Apple, they couldn’t say whether anyone had been in a support call with me just then. They just said Apple states very clearly that it will never initiate outbound calls to customers — unless the customer requests to be contacted.”
Massively freaking out that someone was trying to hijack his digital life, Chris said he changed his passwords and then went to an Apple store and bought a new iPhone. From there, he created a new Apple iCloud account using a brand new email address.
Chris said he then proceeded to get even more system alerts on his new iPhone and iCloud account — all the while still sitting at the local Apple Genius Bar.
Chris told KrebsOnSecurity his Genius Bar tech was mystified about the source of the alerts, but Chris said he suspects that whatever the phishers are abusing to rapidly generate these Apple system alerts requires knowing the phone number on file for the target’s Apple account. After all, that was the only aspect of Chris’s new iPhone and iCloud account that hadn’t changed.
“Ken” is a security industry veteran who spoke on condition of anonymity. Ken said he first began receiving these unsolicited system alerts on his Apple devices earlier this year, but that he has not received any phony Apple support calls as others have reported.
“This recently happened to me in the middle of the night at 12:30 a.m.,” Ken said. “And even though I have my Apple watch set to remain quiet during the time I’m usually sleeping at night, it woke me up with one of these alerts. Thank god I didn’t press ‘Allow,’ which was the first option shown on my watch. I had to scroll watch the wheel to see and press the ‘Don’t Allow’ button.”
Ken shared this photo he took of an alert on his watch that woke him up at 12:30 a.m. Ken said he had to scroll on the watch face to see the “Don’t Allow” button.
Ken didn’t know it when all this was happening (and it’s not at all obvious from the Apple prompts), but clicking “Allow” would not have allowed the attackers to change Ken’s password. Rather, clicking “Allow” displays a six digit PIN that must be entered on Ken’s device — allowing Ken to change his password. It appears that these rapid password reset prompts are being used to make a subsequent inbound phone call spoofing Apple more believable.
Ken said he contacted the real Apple support and was eventually escalated to a senior Apple engineer. The engineer assured Ken that turning on an Apple Recovery Key for his account would stop the notifications once and for all.
A recovery key is an optional security feature that Apple says “helps improve the security of your Apple ID account.” It is a randomly generated 28-character code, and when you enable a recovery key it is supposed to disable Apple’s standard account recovery process. The thing is, enabling it is not a simple process, and if you ever lose that code in addition to all of your Apple devices you will be permanently locked out.
Ken said he enabled a recovery key for his account as instructed, but that it hasn’t stopped the unbidden system alerts from appearing on all of his devices every few days.
KrebsOnSecurity tested Ken’s experience, and can confirm that enabling a recovery key does nothing to stop a password reset prompt from being sent to associated Apple devices. Visiting Apple’s “forgot password” page — https://iforgot.apple.com — asks for an email address and for the visitor to solve a CAPTCHA.
After that, the page will display the last two digits of the phone number tied to the Apple account. Filling in the missing digits and hitting submit on that form will send a system alert, whether or not the user has enabled an Apple Recovery Key.
The password reset page at iforgot.apple.com.
What sanely designed authentication system would send dozens of requests for a password change in the span of a few moments, when the first requests haven’t even been acted on by the user? Could this be the result of a bug in Apple’s systems?
Apple has not yet responded to requests for comment.
Throughout 2022, a criminal hacking group known as LAPSUS$ used MFA bombing to great effect in intrusions at Cisco, Microsoft and Uber. In response, Microsoft began enforcing “MFA number matching,” a feature that displays a series of numbers to a user attempting to log in with their credentials. These numbers must then be entered into the account owner’s Microsoft authenticator app on their mobile device to verify they are logging into the account.
Kishan Bagaria is a hobbyist security researcher and engineer who founded the website texts.com (now owned by Automattic), and he’s convinced Apple has a problem on its end. In August 2019, Bagaria reported to Apple a bug that allowed an exploit he dubbed “AirDoS” because it could be used to let an attacker infinitely spam all nearby iOS devices with a system-level prompt to share a file via AirDrop — a file-sharing capability built into Apple products.
Apple fixed that bug nearly four months later in December 2019, thanking Bagaria in the associated security bulletin. Bagaria said Apple’s fix was to add stricter rate limiting on AirDrop requests, and he suspects that someone has figured out a way to bypass Apple’s rate limit on how many of these password reset requests can be sent in a given timeframe.
“I think this could be a legit Apple rate limit bug that should be reported,” Bagaria said.
Apple seems requires a phone number to be on file for your account, but after you’ve set up the account it doesn’t have to be a mobile phone number. KrebsOnSecurity’s testing shows Apple will accept a VOIP number (like Google Voice). So, changing your account phone number to a VOIP number that isn’t widely known would be one mitigation here.
One caveat with the VOIP number idea: Unless you include a real mobile number, Apple’s iMessage and Facetime applications will be disabled for that device. This might a bonus for those concerned about reducing the overall attack surface of their Apple devices, since zero-click zero-days in these applications have repeatedly been used by spyware purveyors.
Also, it appears Apple’s password reset system will accept and respect email aliases. Adding a “+” character after the username portion of your email address — followed by a notation specific to the site you’re signing up at — lets you create an infinite number of unique email addresses tied to the same account.
For instance, if I were signing up at example.com, I might give my email address as krebsonsecurity+example@gmail.com. Then, I simply go back to my inbox and create a corresponding folder called “Example,” along with a new filter that sends any email addressed to that alias to the Example folder. In this case, however, perhaps a less obvious alias than “+apple” would be advisable.
Update, March 27, 5:06 p.m. ET: Added perspective on Ken’s experience. Also included a What Can You Do? section.
Countless smartphones seized in arrests and searches by police forces across the United States are being auctioned online without first having the data on them erased, a practice that can lead to crime victims being re-victimized, a new study found. In response, the largest online marketplace for items seized in U.S. law enforcement investigations says it now ensures that all phones sold through its platform will be data-wiped prior to auction.
Researchers at the University of Maryland last year purchased 228 smartphones sold “as-is” from PropertyRoom.com, which bills itself as the largest auction house for police departments in the United States. Of phones they won at auction (at an average of $18 per phone), the researchers found 49 had no PIN or passcode; they were able to guess an additional 11 of the PINs by using the top-40 most popular PIN or swipe patterns.
Phones may end up in police custody for any number of reasons — such as its owner was involved in identity theft — and in these cases the phone itself was used as a tool to commit the crime.
“We initially expected that police would never auction these phones, as they would enable the buyer to recommit the same crimes as the previous owner,” the researchers explained in a paper released this month. “Unfortunately, that expectation has proven false in practice.”
The researchers said while they could have employed more aggressive technological measures to work out more of the PINs for the remaining phones they bought, they concluded based on the sample that a great many of the devices they won at auction had probably not been data-wiped and were protected only by a PIN.
Beyond what you would expect from unwiped second hand phones — every text message, picture, email, browser history, location history, etc. — the 61 phones they were able to access also contained significant amounts of data pertaining to crime — including victims’ data — the researchers found.
Some readers may be wondering at this point, “Why should we care about what happens to a criminal’s phone?” First off, it’s not entirely clear how these phones ended up for sale on PropertyRoom.
“Some folks are like, ‘Yeah, whatever, these are criminal phones,’ but are they?” said Dave Levin, an assistant professor of computer science at University of Maryland.
“We started looking at state laws around what they’re supposed to do with lost or stolen property, and we found that most of it ends up going the same route as civil asset forfeiture,” Levin continued. “Meaning, if they can’t find out who owns something, it eventually becomes the property of the state and gets shipped out to these resellers.”
Also, the researchers found that many of the phones clearly had personal information on them regarding previous or intended targets of crime: A dozen of the phones had photographs of government-issued IDs. Three of those were on phones that apparently belonged to sex workers; their phones contained communications with clients.
An overview of the phone functionality and data accessibility for phones purchased by the researchers.
One phone had full credit files for eight different people on it. On another device they found a screenshot including 11 stolen credit cards that were apparently purchased from an online carding shop. On yet another, the former owner had apparently been active in a Telegram group chat that sold tutorials on how to run identity theft scams.
The most interesting phone from the batches they bought at auction was one with a sticky note attached that included the device’s PIN and the notation “Gry Keyed,” no doubt a reference to the Graykey software that is often used by law enforcement agencies to brute-force a mobile device PIN.
“That one had the PIN on the back,” Levin said. “The message chain on that phone had 24 Experian and TransUnion credit histories”.
The University of Maryland team said they took care in their research not to further the victimization of people whose information was on the devices they purchased from PropertyRoom.com. That involved ensuring that none of the devices could connect to the Internet when powered on, and scanning all images on the devices against known hashes for child sexual abuse material.
It is common to find phones and other electronics for sale on auction platforms like eBay that have not been wiped of sensitive data, but in those cases eBay doesn’t possess the items being sold. In contrast, platforms like PropertyRoom obtain devices and resell them at auction directly.
PropertyRoom did not respond to multiple requests for comment. But the researchers said sometime in the past few months PropertyRoom began posting a notice stating that all mobile devices would be wiped of their data before being sold at auction.
“We informed them of our research in October 2022, and they responded that they would review our findings internally,” Levin said. “They stopped selling them for a while, but then it slowly came back, and then we made sure we won every auction. And all of the ones we got from that were indeed wiped, except there were four devices that had external SD [storage] cards in them that weren’t wiped.”
A copy of the University of Maryland study is here (PDF).
Image: Shutterstock.com
Three different cybercriminal groups claimed access to internal networks at communications giant T-Mobile in more than 100 separate incidents throughout 2022, new data suggests. In each case, the goal of the attackers was the same: Phish T-Mobile employees for access to internal company tools, and then convert that access into a cybercrime service that could be hired to divert any T-Mobile user’s text messages and phone calls to another device.
The conclusions above are based on an extensive analysis of Telegram chat logs from three distinct cybercrime groups or actors that have been identified by security researchers as particularly active in and effective at “SIM-swapping,” which involves temporarily seizing control over a target’s mobile phone number.
Countless websites and online services use SMS text messages for both password resets and multi-factor authentication. This means that stealing someone’s phone number often can let cybercriminals hijack the target’s entire digital life in short order — including access to any financial, email and social media accounts tied to that phone number.
All three SIM-swapping entities that were tracked for this story remain active in 2023, and they all conduct business in open channels on the instant messaging platform Telegram. KrebsOnSecurity is not naming those channels or groups here because they will simply migrate to more private servers if exposed publicly, and for now those servers remain a useful source of intelligence about their activities.
Each advertises their claimed access to T-Mobile systems in a similar way. At a minimum, every SIM-swapping opportunity is announced with a brief “Tmobile up!” or “Tmo up!” message to channel participants. Other information in the announcements includes the price for a single SIM-swap request, and the handle of the person who takes the payment and information about the targeted subscriber.
The information required from the customer of the SIM-swapping service includes the target’s phone number, and the serial number tied to the new SIM card that will be used to receive text messages and phone calls from the hijacked phone number.
Initially, the goal of this project was to count how many times each entity claimed access to T-Mobile throughout 2022, by cataloging the various “Tmo up!” posts from each day and working backwards from Dec. 31, 2022.
But by the time we got to claims made in the middle of May 2022, completing the rest of the year’s timeline seemed unnecessary. The tally shows that in the last seven-and-a-half months of 2022, these groups collectively made SIM-swapping claims against T-Mobile on 104 separate days — often with multiple groups claiming access on the same days.
The 104 days in the latter half of 2022 in which different known SIM-swapping groups claimed access to T-Mobile employee tools.
KrebsOnSecurity shared a large amount of data gathered for this story with T-Mobile. The company declined to confirm or deny any of these claimed intrusions. But in a written statement, T-Mobile said this type of activity affects the entire wireless industry.
“And we are constantly working to fight against it,” the statement reads. “We have continued to drive enhancements that further protect against unauthorized access, including enhancing multi-factor authentication controls, hardening environments, limiting access to data, apps or services, and more. We are also focused on gathering threat intelligence data, like what you have shared, to help further strengthen these ongoing efforts.”
While it is true that each of these cybercriminal actors periodically offer SIM-swapping services for other mobile phone providers — including AT&T, Verizon and smaller carriers — those solicitations appear far less frequently in these group chats than T-Mobile swap offers. And when those offers do materialize, they are considerably more expensive.
The prices advertised for a SIM-swap against T-Mobile customers in the latter half of 2022 ranged between USD $1,000 and $1,500, while SIM-swaps offered against AT&T and Verizon customers often cost well more than twice that amount.
To be clear, KrebsOnSecurity is not aware of specific SIM-swapping incidents tied to any of these breach claims. However, the vast majority of advertisements for SIM-swapping claims against T-Mobile tracked in this story had two things in common that set them apart from random SIM-swapping ads on Telegram.
First, they included an offer to use a mutually trusted “middleman” or escrow provider for the transaction (to protect either party from getting scammed). More importantly, the cybercriminal handles that were posting ads for SIM-swapping opportunities from these groups generally did so on a daily or near-daily basis — often teasing their upcoming swap events in the hours before posting a “Tmo up!” message announcement.
In other words, if the crooks offering these SIM-swapping services were ripping off their customers or claiming to have access that they didn’t, this would be almost immediately obvious from the responses of the more seasoned and serious cybercriminals in the same chat channel.
There are plenty of people on Telegram claiming to have SIM-swap access at major telecommunications firms, but a great many such offers are simply four-figure scams, and any pretenders on this front are soon identified and banned (if not worse).
One of the groups that reliably posted “Tmo up!” messages to announce SIM-swap availability against T-Mobile customers also reliably posted “Tmo down!” follow-up messages announcing exactly when their claimed access to T-Mobile employee tools was discovered and revoked by the mobile giant.
A review of the timestamps associated with this group’s incessant “Tmo up” and “Tmo down” posts indicates that while their claimed access to employee tools usually lasted less than an hour, in some cases that access apparently went undiscovered for several hours or even days.
How could these SIM-swapping groups be gaining access to T-Mobile’s network as frequently as they claim? Peppered throughout the daily chit-chat on their Telegram channels are solicitations for people urgently needed to serve as “callers,” or those who can be hired to social engineer employees over the phone into navigating to a phishing website and entering their employee credentials.
Allison Nixon is chief research officer for the New York City-based cybersecurity firm Unit 221B. Nixon said these SIM-swapping groups will typically call employees on their mobile devices, pretend to be someone from the company’s IT department, and then try to get the person on the other end of the line to visit a phishing website that mimics the company’s employee login page.
Nixon argues that many people in the security community tend to discount the threat from voice phishing attacks as somehow “low tech” and “low probability” threats.
“I see it as not low-tech at all, because there are a lot of moving parts to phishing these days,” Nixon said. “You have the caller who has the employee on the line, and the person operating the phish kit who needs to spin it up and down fast enough so that it doesn’t get flagged by security companies. Then they have to get the employee on that phishing site and steal their credentials.”
In addition, she said, often there will be yet another co-conspirator whose job it is to use the stolen credentials and log into employee tools. That person may also need to figure out how to make their device pass “posture checks,” a form of device authentication that some companies use to verify that each login is coming only from employer-issued phones or laptops.
For aspiring criminals with little experience in scam calling, there are plenty of sample call transcripts available on these Telegram chat channels that walk one through how to impersonate an IT technician at the targeted company — and how to respond to pushback or skepticism from the employee. Here’s a snippet from one such tutorial that appeared recently in one of the SIM-swapping channels:
“Hello this is James calling from Metro IT department, how’s your day today?”
(yea im doing good, how r u)
i’m doing great, thank you for asking
i’m calling in regards to a ticket we got last week from you guys, saying you guys were having issues with the network connectivity which also interfered with [Microsoft] Edge, not letting you sign in or disconnecting you randomly. We haven’t received any updates to this ticket ever since it was created so that’s why I’m calling in just to see if there’s still an issue or not….”
The TMO UP data referenced above, combined with comments from the SIM-swappers themselves, indicate that while many of their claimed accesses to T-Mobile tools in the middle of 2022 lasted hours on end, both the frequency and duration of these events began to steadily decrease as the year wore on.
T-Mobile declined to discuss what it may have done to combat these apparent intrusions last year. However, one of the groups began to complain loudly in late October 2022 that T-Mobile must have been doing something that was causing their phished access to employee tools to die very soon after they obtained it.
One group even remarked that they suspected T-Mobile’s security team had begun monitoring their chats.
Indeed, the timestamps associated with one group’s TMO UP/TMO DOWN notices show that their claimed access was often limited to less than 15 minutes throughout November and December of 2022.
Whatever the reason, the calendar graphic above clearly shows that the frequency of claimed access to T-Mobile decreased significantly across all three SIM-swapping groups in the waning weeks of 2022.
T-Mobile US reported revenues of nearly $80 billion last year. It currently employs more than 71,000 people in the United States, any one of whom can be a target for these phishers.
T-Mobile declined to answer questions about what it may be doing to beef up employee authentication. But Nicholas Weaver, a researcher and lecturer at University of California, Berkeley’s International Computer Science Institute, said T-Mobile and all the major wireless providers should be requiring employees to use physical security keys for that second factor when logging into company resources.
A U2F device made by Yubikey.
“These breaches should not happen,” Weaver said. “Because T-Mobile should have long ago issued all employees security keys and switched to security keys for the second factor. And because security keys provably block this style of attack.”
The most commonly used security keys are inexpensive USB-based devices. A security key implements a form of multi-factor authentication known as Universal 2nd Factor (U2F), which allows the user to complete the login process simply by inserting the USB key and pressing a button on the device. The key works without the need for any special software drivers.
The allure of U2F devices for multi-factor authentication is that even if an employee who has enrolled a security key for authentication tries to log in at an impostor site, the company’s systems simply refuse to request the security key if the user isn’t on their employer’s legitimate website, and the login attempt fails. Thus, the second factor cannot be phished, either over the phone or Internet.
Nixon said one confounding aspect of SIM-swapping is that these criminal groups tend to recruit teenagers to do their dirty work.
“A huge reason this problem has been allowed to spiral out of control is because children play such a prominent role in this form of breach,” Nixon said.
Nixon said SIM-swapping groups often advertise low-level jobs on places like Roblox and Minecraft, online games that are extremely popular with young adolescent males.
“Statistically speaking, that kind of recruiting is going to produce a lot of people who are underage,” she said. “They recruit children because they’re naive, you can get more out of them, and they have legal protections that other people over 18 don’t have.”
For example, she said, even when underage SIM-swappers are arrested, the offenders tend to go right back to committing the same crimes as soon as they’re released.
In January 2023, T-Mobile disclosed that a “bad actor” stole records on roughly 37 million current customers, including their name, billing address, email, phone number, date of birth, and T-Mobile account number.
In August 2021, T-Mobile acknowledged that hackers made off with the names, dates of birth, Social Security numbers and driver’s license/ID information on more than 40 million current, former or prospective customers who applied for credit with the company. That breach came to light after a hacker began selling the records on a cybercrime forum.
In the shadow of such mega-breaches, any damage from the continuous attacks by these SIM-swapping groups can seem insignificant by comparison. But Nixon says it’s a mistake to dismiss SIM-swapping as a low volume problem.
“Logistically, you may only be able to get a few dozen or a hundred SIM-swaps in a day, but you can pick any customer you want across their entire customer base,” she said. “Just because a targeted account takeover is low volume doesn’t mean it’s low risk. These guys have crews that go and identify people who are high net worth individuals and who have a lot to lose.”
Nixon said another aspect of SIM-swapping that causes cybersecurity defenders to dismiss the threat from these groups is the perception that they are full of low-skilled “script kiddies,” a derisive term used to describe novice hackers who rely mainly on point-and-click hacking tools.
“They underestimate these actors and say this person isn’t technically sophisticated,” she said. “But if you’re rolling around in millions worth of stolen crypto currency, you can buy that sophistication. I know for a fact some of these compromises were at the hands of these ‘script kiddies,’ but they’re not ripping off other people’s scripts so much as hiring people to make scripts for them. And they don’t care what gets the job done, as long as they get to steal the money.”
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.
Some of more tech-savvy Democrats in the U.S. Senate are asking the Federal Trade Commission (FTC) to investigate identity-proofing company ID.me for “deceptive statements” the company and its founder allegedly made over how they handle facial recognition data collected on behalf of the Internal Revenue Service, which until recently required anyone seeking a new IRS account online to provide a live video selfie to ID.me.
In a letter to FTC Chair Lina Khan, the Senators charge that ID.me’s CEO Blake Hall has offered conflicting statements about how his company uses the facial scan data it collects on behalf of the federal government and many states that use the ID proofing technology to screen applicants for unemployment insurance.
The lawmakers say that in public statements and blog posts, ID.me has frequently emphasized the difference between two types of facial recognition: One-to-one, and one-to-many. In the one-to-one approach, a live video selfie is compared to the image on a driver’s license, for example. One-to-many facial recognition involves comparing a face against a database of other faces to find any potential matches.
Americans have particular reason to be concerned about the difference between these two types of facial recognition, says the letter to the FTC, signed by Sens. Cory Booker (D-N.J.), Edward Markey (D-Mass.), Alex Padilla (D-Calif.), and Ron Wyden (D-Ore.):
“While one-to-one recognition involves a one-time comparison of two images in order to confirm an applicant’s identity, the use of one-to-many recognition means that millions of innocent people will have their photographs endlessly queried as part of a digital ‘line up.’ Not only does this violate individuals’ privacy, but the inevitable false matches associated with one-to-many recognition can result in applicants being wrongly denied desperately-needed services for weeks or even months as they try to get their case reviewed.”
“This risk is especially acute for people of color: NIST’s Facial Recognition Vendor Test found that many facial recognition algorithms have rates of false matches that are as much as 100 times higher for individuals from countries in West Africa, East Africa and East Asia than for individuals from Eastern European countries. This means Black and Asian Americans could be disproportionately likely to be denied benefits due to a false match in a one-to-many facial recognition system.”
The lawmakers say that throughout the latter half of 2021, ID.me published statements and blog posts stating it did not use one-to-many facial recognition and that the approach was “problematic” and “tied to surveillance operations.” But several days after a Jan. 16, 2022 post here about the IRS’s new facial ID requirement went viral and prompted a public backlash, Hall acknowledged in a LinkedIn posting that ID.me does use one-to-many facial recognition.
“Within days, the company edited the numerous blog posts and white papers on its website that previously stated the company did not use one-to-many to reflect the truth,” the letter alleges. “According to media reports, the company’s decision to correct its prior misleading statements came after mounting internal pressure from its employees.”
Cyberscoop’s Tonya Riley published excerpts from internal ID.me employee Slack messages wherein some expressed dread and unease with the company’s equivocation on its use of one-to-many facial recognition.
In February, the IRS announced it would no longer require facial scans or other biometric data from taxpayers seeking to create an account at the agency’s website. The agency also pledged that any biometric data shared with ID.me would be permanently deleted.
But the IRS still requires new account applicants to sign up with either ID.me or Login.gov, a single sign-on solution already used to access 200 websites run by 28 federal agencies. It also still offers the option of providing a live selfie for verification purposes, although the IRS says this data will be deleted automatically.
Asked to respond to concerns raised in the letter from Senate lawmakers, ID.me instead touted its successes in stopping fraud.
“Five state workforce agencies have publicly credited ID.me with helping to prevent $238 billion dollars in fraud,” the statement reads. “Conditions were so bad during the pandemic that the deputy assistant director of the FBI called the fraud ‘an economic attack on the United States.’ ID.me played a critical role in stopping that attack in more than 20 states where the service was rapidly adopted for its equally important ability to increase equity and verify individuals left behind by traditional options. We look forward to cooperating with all relevant government bodies to clear up any misunderstandings.”
As Cyberscoop reported on Apr. 14, the House Oversight and Reform Committee last month began an investigation into ID.me’s practices, with committee chairwoman Carolyn Maloney (D-N.Y.) saying the committee’s questions to the company would help shape policy on how the government wields facial recognition technology.
A copy of the letter the senators sent to the FTC is here (PDF).
FreshRSS 