Microsoft Patch Tuesday, April 2021 Edition

April 13, 2021
30 Comments

Microsoft today released updates to plug at least 110 security holes in its Windows operating systems and other products. The patches include four security fixes for Microsoft Exchange Server — the same systems that have been besieged by attacks on four separate (and zero-day) bugs in the email software over the past month. Redmond also patched a Windows flaw that is actively being exploited in the wild.

Nineteen of the vulnerabilities fixed this month earned Microsoft’s most-dire “Critical” label, meaning they could be used by malware or malcontents to seize remote control over vulnerable Windows systems without any help from users.

Microsoft released updates to fix four more flaws in Exchange Server versions 2013-2019 (CVE-2021-28480, CVE-2021-28481, CVE-2021-28482, CVE-2021-28483). Interestingly, all four were reported by the U.S. National Security Agency, although Microsoft says it also found two of the bugs internally. A Microsoft blog post published along with today’s patches urges Exchange Server users to make patching their systems a top priority.

Satnam Narang, staff research engineer at Tenable, said these vulnerabilities have been rated ‘Exploitation More Likely’ using Microsoft’s Exploitability Index.

“Two of the four vulnerabilities (CVE-2021-28480, CVE-2021-28481) are pre-authentication, meaning an attacker does not need to authenticate to the vulnerable Exchange server to exploit the flaw,” Narang said. “With the intense interest in Exchange Server since last month, it is crucial that organizations apply these Exchange Server patches immediately.”

Also patched today was a vulnerability in Windows (CVE-2021-28310) that’s being exploited in active attacks already. The flaw allows an attacker to elevate their privileges on a target system.

“This does mean that they will either need to log on to a system or trick a legitimate user into running the code on their behalf,” said Dustin Childs of Trend Micro. “Considering who is listed as discovering this bug, it is probably being used in malware. Bugs of this nature are typically combined with other bugs, such as browser bug of PDF exploit, to take over a system.”

In a technical writeup on what they’ve observed since finding and reporting attacks on CVE-2021-28310, researchers at Kaspersky Lab noted the exploit they saw was likely used together with other browser exploits to escape “sandbox” protections of the browser.

“Unfortunately, we weren’t able to capture a full chain, so we don’t know if the exploit is used with another browser zero-day, or coupled with known, patched vulnerabilities,” Kaspersky’s researchers wrote. Continue reading →

ParkMobile Breach Exposes License Plate Data, Mobile Numbers of 21M Users

April 12, 2021
51 Comments

Someone is selling account information for 21 million customers of ParkMobile, a mobile parking app that’s popular in North America. The stolen data includes customer email addresses, dates of birth, phone numbers, license plate numbers, hashed passwords and mailing addresses.

KrebsOnSecurity first heard about the breach from Gemini Advisory, a New York City based threat intelligence firm that keeps a close eye on the cybercrime forums. Gemini shared a new sales thread on a Russian-language crime forum that included my ParkMobile account information in the accompanying screenshot of the stolen data.

Included in the data were my email address and phone number, as well as license plate numbers for four different vehicles we have used over the past decade.

Asked about the sales thread, Atlanta-based ParkMobile said the company published a notification on Mar. 26 about “a cybersecurity incident linked to a vulnerability in a third-party software that we use.”

“In response, we immediately launched an investigation with the assistance of a leading cybersecurity firm to address the incident,” the notice reads. “Out of an abundance of caution, we have also notified the appropriate law enforcement authorities. The investigation is ongoing, and we are limited in the details we can provide at this time.”

The statement continues: “Our investigation indicates that no sensitive data or Payment Card Information, which we encrypt, was affected. Meanwhile, we have taken additional precautionary steps since learning of the incident, including eliminating the third-party vulnerability, maintaining our security, and continuing to monitor our systems.”

Asked for clarification on what the attackers did access, ParkMobile confirmed it included basic account information – license plate numbers, and if provided, email addresses and/or phone numbers, and vehicle nickname.

“In a small percentage of cases, there may be mailing addresses,” spokesman Jeff Perkins said.
Continue reading →

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Are You One of the 533M People Who Got Facebooked?

April 6, 2021
78 Comments

Ne’er-do-wells leaked personal data — including phone numbers — for some 553 million Facebook users this week. Facebook says the data was collected before 2020 when it changed things to prevent such information from being scraped from profiles. To my mind, this just reinforces the need to remove mobile phone numbers from all of your online accounts wherever feasible. Meanwhile, if you’re a Facebook product user and want to learn if your data was leaked, there are easy ways to find out.

The HaveIBeenPwned project, which collects and analyzes hundreds of database dumps containing information about billions of leaked accounts, has incorporated the data into his service. Facebook users can enter the mobile number (in international format) associated with their account and see if those digits were exposed in the new data dump (HIBP doesn’t show you any data, just gives you a yes/no on whether your data shows up).

The phone number associated with my late Facebook account (which I deleted in Jan. 2020) was not in HaveIBeenPwned, but then again Facebook claims to have more than 2.7 billion active monthly users.

It appears much of this database has been kicking around the cybercrime underground in one form or another since last summer at least. According to a Jan. 14, 2021 Twitter post from Under the Breach’s Alon Gal, the 533 million Facebook accounts database was first put up for sale back in June 2020, offering Facebook profile data from 100 countries, including name, mobile number, gender, occupation, city, country, and marital status.

Under The Breach also said back in January that someone had created a Telegram bot allowing users to query the database for a low fee, and enabling people to find the phone numbers linked to a large number of Facebook accounts.

A cybercrime forum ad from June 2020 selling a database of 533 Million Facebook users. Image: @UnderTheBreach

Many people may not consider their mobile phone number to be private information, but there is a world of misery that bad guys, stalkers and creeps can visit on your life just by knowing your mobile number. Sure they could call you and harass you that way, but more likely they will see how many of your other accounts — at major email providers and social networking sites like Facebook, Twitter, Instagram, e.g. — rely on that number for password resets. Continue reading →

Ransom Gangs Emailing Victim Customers for Leverage

April 5, 2021
10 Comments

Some of the top ransomware gangs are deploying a new pressure tactic to push more victim organizations into paying an extortion demand: Emailing the victim’s customers and partners directly, warning that their data will be leaked to the dark web unless they can convince the victim firm to pay up.

This letter is from the Clop ransomware gang, putting pressure on a recent victim named on Clop’s dark web shaming site.

“Good day! If you received this letter, you are a customer, buyer, partner or employee of [victim],” the missive reads. “The company has been hacked, data has been stolen and will soon be released as the company refuses to protect its peoples’ data.”

“We inform you that information about you will be published on the darknet [link to dark web victim shaming page] if the company does not contact us,” the message concludes. “Call or write to this store and ask to protect your privacy!!!!”

The message above was sent to a customer of RaceTrac Petroleum, an Atlanta company that operates more than 650 retail gasoline convenience stores in 12 southeastern states. The person who shared that screenshot above isn’t a distributor or partner of RaceTrac, but they said they are a RaceTrac rewards member, so the company definitely has their email address and other information.

Several gigabytes of the company’s files — including employee tax and financial records — have been posted to the victim shaming site for the Clop ransomware gang.

In response to questions from KrebsOnSecurity, RaceTrac said it was recently impacted by a security incident affecting one of its third-party service providers, Accellion Inc.

For the past few months, attackers have been exploiting a a zero-day vulnerability in Accellion File Transfer Appliance (FTA) software, a flaw that has been seized upon by Clop to break into dozens of other major companies like oil giant Shell and security firm Qualys.

“By exploiting a previously undetected software vulnerability, unauthorized parties were able to access a subset of RaceTrac data stored in the Accellion File Transfer Service, including email addresses and first names of some of our RaceTrac Rewards Loyalty users,” the company wrote. “This incident was limited to the aforementioned Accellion services and did not impact RaceTrac’s corporate network. The systems used for processing guest credit, debit and RaceTrac Rewards transactions were not impacted.”

The same extortion pressure email has been going out to people associated with the University of California, which was one of several large U.S. universities that got hit with Clop ransomware recently. Most of those university ransomware incidents appeared to be tied to attacks on attacks on the same Accellion vulnerability, and the company has acknowledged roughly a third of its customers on that appliance got compromised as a result.

Clop is one of several ransom gangs that will demand two ransoms: One for a digital key needed to unlock computers and data from file encryption, and a second to avoid having stolen data published or sold online. That means even victims who opt not to pay to get their files and servers back still have to decide whether to pay the second ransom to protect the privacy of their customers.

As I noted in Why Paying to Delete Stolen Data is Bonkers, leaving aside the notion that victims might have any real expectation the attackers will actually destroy the stolen data, new research suggests a fair number of victims who do pay up may see some or all of the stolen data published anyway. Continue reading →

New KrebsOnSecurity Mobile-Friendly Site

April 1, 2021
70 Comments

Dear Readers, this has been long overdue, but at last I give you a more responsive, mobile-friendly version of KrebsOnSecurity. We tried to keep the visual changes to a minimum and focus on a simple theme that presents information in a straightforward, easy-to-read format. Please bear with us over the next few days as we hunt down the gremlins in the gears.

We were shooting for responsive (fast) and uncluttered. Hopefully, we achieved that and this new design will render well in whatever device you use to view it. If something looks amiss, please don’t hesitate to drop a note in the comments below.

NB: KrebsOnSecurity has not changed any of its advertising practices: The handful of ads we run are still image-only creatives that are vetted by me and served in-house. If you’re blocking ads on this site, please consider adding an exception here. Thank you!

No, I Did Not Hack Your MS Exchange Server

March 28, 2021
59 Comments

New data suggests someone has compromised more than 21,000 Microsoft Exchange Server email systems worldwide and infected them with malware that invokes both KrebsOnSecurity and Yours Truly by name.

Let’s just get this out of the way right now: It wasn’t me.

The Shadowserver Foundation, a nonprofit that helps network owners identify and fix security threats, says it has found 21,248 different Exchange servers which appear to be compromised by a backdoor and communicating with brian[.]krebsonsecurity[.]top (NOT a safe domain, hence the hobbling).

Shadowserver has been tracking wave after wave of attacks targeting flaws in Exchange that Microsoft addressed earlier this month in an emergency patch release. The group looks for attacks on Exchange systems using a combination of active Internet scans and “honeypots” — systems left vulnerable to attack so that defenders can study what attackers are doing to the devices and how.

David Watson, a longtime member and director of the Shadowserver Foundation Europe, says his group has been keeping a close eye on hundreds of unique variants of backdoors (a.k.a. “web shells”) that various cybercrime groups worldwide have been using to commandeer any unpatched Exchange servers. These backdoors give an attacker complete, remote control over the Exchange server (including any of the server’s emails).

On Mar. 26, Shadowserver saw an attempt to install a new type of backdoor in compromised Exchange Servers, and with each hacked host it installed the backdoor in the same place: “/owa/auth/babydraco.aspx.”

“The web shell path that was dropped was new to us,” said Watson said. “We have been testing 367 known web shell paths via scanning of Exchange servers.”

OWA refers to Outlook Web Access, the Web-facing portion of on-premises Exchange servers. Shadowserver’s honeypots saw multiple hosts with the Babydraco backdoor doing the same thing: Running a Microsoft Powershell script that fetches the file “krebsonsecurity.exe” from the Internet address 159.65.136[.]128. Oddly, none of the several dozen antivirus tools available to scan the file at Virustotal.com currently detect it as malicious.

The Krebsonsecurity file also installs a root certificate, modifies the system registry, and tells Windows Defender not to scan the file. Watson said the Krebsonsecurity file will attempt to open up an encrypted connection between the Exchange server and the above-mentioned IP address, and send a small amount of traffic to it each minute. Continue reading →

Phish Leads to Breach at Calif. State Controller

March 23, 2021
35 Comments

A phishing attack last week gave attackers access to email and files at the California State Controller’s Office (SCO), an agency responsible for handling more than $100 billion in public funds each year. The phishers had access for more than 24 hours, and sources tell KrebsOnSecurity the intruders used that time to steal Social Security numbers and sensitive files on thousands of state workers, and to send targeted phishing messages to at least 9,000 other workers and their contacts.

A notice of breach posted by the California State Controller’s Office.

In a “Notice of Data Breach” message posted on Saturday, Mar. 20, the Controller’s Office said that for more than 24 hours starting on the afternoon of March 18 attackers had access to the email records of an employee in its Unclaimed Property Division after the employee clicked a phishing link and then entered their email ID and password.

“The SCO has reason to believe the compromised email account had personal identifying information contained in Unclaimed Property Holder Reports,” the agency said, urging state employees contacted by the agency to place fraud alerts on their credit files with the major consumer bureaus.  “The unauthorized user also sent potentially malicious emails to some of the SCO employee’s contacts.”

The SCO responded in an email that no state employee data was compromised.

“A single employee email account was briefly compromised by a spear phishing attack and promptly disabled,” SCO spokesperson Jennifer Hanson said. “SCO has notified the employee’s contacts who may have received a potentially malicious email from the unauthorized user. SCO team members have identified all personal information included in the compromised email account and begun the process of notifying affected parties. The Controller is going over and beyond the notification requirements in law by providing both actual mailed notification and substitute notification in an effort to ensure the broadest possible notification.”

A source in an adjacent California state agency who’s been tracking the incident internally with other employees says the SCO forgot to mention the intruders also had access to the phished employee’s Microsoft Office 365 files — and potentially any files shared with that account across the state network.

“This isn’t even the full extent of the breach,” said the California state employee, who spoke on condition of anonymity. Continue reading →

RedTorch Formed from Ashes of Norse Corp.

March 22, 2021
26 Comments

Remember Norse Corp., the company behind the interactive “pew-pew” cyber attack map shown in the image below? Norse imploded rather suddenly in 2016 following a series of managerial missteps and funding debacles. Now, the founders of Norse have launched a new company with a somewhat different vision: RedTorch, which for the past two years has marketed a mix of services to high end celebrity clients, including spying and anti-spying tools and services.

A snapshot of Norse’s semi-live attack map, circa Jan. 2016.

Norse’s attack map was everywhere for several years, and even became a common sight in the “brains” of corporate security operations centers worldwide. Even if the data that fueled the maps was not particularly useful, the images never failed to enthrall visitors viewing them on room-sized screens.

“In the tech-heavy, geek-speak world of cybersecurity, these sorts of infographics and maps are popular because they promise to make complicated and boring subjects accessible and sexy,” I wrote in a January 2016 story about Norse’s implosion. “And Norse’s much-vaunted interactive attack map was indeed some serious eye candy: It purported to track the source and destination of countless Internet attacks in near real-time, and showed what appeared to be multicolored fireballs continuously arcing across the globe.”

That story showed the core Norse team had a history of ambitious but ultimately failed or re-branded companies. One company proclaimed it was poised to spawn a network of cyber-related firms, but instead ended up selling cigarettes online. That company, which later came under investigation by state regulators concerned about underage smokers, later rebranded to another start-up that tried to be an online copyright cop.

Flushed with venture capital funding in 2012, Norse’s founders started hiring dozens of talented cybersecurity professionals. By 2014 it was throwing lavish parties at top  Internet security conferences. It spent quite a bit of money on marketing gimmicks and costly advertising stunts, burning through millions in investment funding. In 2016, financial reality once again would catch up with the company’s leadership when Norse abruptly ceased operations and was forced to lay off most of its staff.

Now the top executives behind Norse Corp. are working on a new venture: A corporate security and investigations company called RedTorch that’s based in Woodland Hills, Calif, the home of many Hollywood celebrities.

RedTorch’s website currently displays a “We’re coming soon” placeholder page. But a version of the site that ran for two years beginning in 2018 explained what clients can expect from the company’s services:

  • “Frigg Mobile Intelligence,” for helping celebrities and other wealthy clients do background checks on the people in their lives;
  • “Cheetah Counter Surveillance” tools/services to help deter others from being able to spy on clients electronically;
  • A “Centurion Research” tool for documenting said snooping on others.

An ad for RedTorch’s “Cheetah” counter-surveillance tech. The Guy Fawkes mask/Anonymous threat featured prominently and often on RedTorch’s website.

The closest thing to eye candy for RedTorch is its Cheetah Counter Surveillance product line, a suite of hardware and software meant to be integrated into other security products which — according to RedTorch — constantly sweeps the client’s network and physical office space with proprietary technology designed to detect remote listening bugs and other spying devices.

Frigg, another core RedTorch offering, is…well, friggin’ spooky:

“Frigg is the easiest way to do a full background check and behavioral analysis on people,” the product pitch reads. “Frigg not only shows background checks, but social profiles and a person’s entire internet footprint, too. This allows one to evaluate a person’s moral fiber and ethics. Frigg employs machine learning and analytics on all known data from a subject’s footprint, delivering instant insight so you can make safer decisions, instantly.”

The background checking service from RedTorch, called Frigg, says it’s building “one of the world’s largest facial recognition databases and a very accurate facial recognition match standard.”

Frigg promises to include “elements that stems [sic] from major data hacks of known systems like Ashley Madison, LinkedIn, Dropbox, Fling.com, AdultFriendFinder and hundreds more. Victims of those breaches lost a lot of private data including passwords, and Frigg will help them secure their private data in the future. The matching that is shown will use email, phone and full name correlation.”

From the rest of Frigg:

Frigg references sanction lists such as OFAC, INTERPOL wanted persons, and many more international and domestic lists. Known locations results are based on social media profiles and metadata where, for example, there was an image posted that showed GPS location, or the profile mentions locations among its comments.

Frigg provides the option of continuous monitoring on searched background reports. Notification will be sent or shown once an important update or change has been detected

The flagship version of Frigg will allow a user to upload a picture of a face and get a full background check instantly. RedTorch is working to develop one of the world’s largest facial recognition databases and a very accurate facial recognition match standard.

WHO IS REDTORCH?

The co-founders of Norse Networks, “Mr. White” (left) Norse Corp. co-founder and RedTorch CEO Henry Marx;, and “Mr. Grey,” CTO and Norse Corp. co-founder Tommy Stiansen.

RedTorch claims it is building a huge facial recognition database, so it’s perhaps no surprise that its founders prefer to obscure theirs. The contact email on RedTorch says henry @redtorch dot com. That address belongs to RedTorch Inc. CEO Henry Marx, a former music industry executive and co-founder of Norse Networks.

Marx did not respond to requests for comment. Nor did any of the other former Norse Corp. executives mentioned throughout this story. So I should emphasize that it’s not even clear whether the above-mentioned products and services from RedTorch actually exist.

One executive at Red Torch told this author privately that the company had plenty of high-paying clients, although that person declined to be more specific about what RedTorch might do for those clients or why the company’s site was currently in transition.

Now a cadre of former Norse Corp. employees who have been tracking the company’s past executives say they’ve peered through the playful subterfuge in the anonymous corporate identities on the archived RedTorch website.

Marx appears to be the “Mr. White” referenced in the screenshot above, taken from an archived Aug. 2020 version of RedTorch.com. He is wearing a Guy Fawkes mask, a symbol favored by the Anonymous hacker collective, the doomed man behind the failed Gunpowder plot of 1604 in England, and by possibly the most annoying costumes that darken your front door each Halloween.

Mr. White says he has “over 30 years in the entertainment industry; built numerous brands and controlled several areas of the entertainment business side,” and that he’s “accomplished over 200 million sold artist performances.”

Pictured beside Mr. White is RedTorch’s co-founder, “Mr. Grey.” Norse watchers say that would be Tommy Stiansen, the Norwegian former co-founder of Norse Corp. whose LinkedIn profile says is now chief technology officer at RedTorch. One of his earliest companies provided “operational billing solutions for telecom networks.”

“Extensive experience from Telecom industry as executive and engineer,” reads Mr. Grey’s profile at RedTorch. “Decades of Cyber security experience, entrepreneurship and growing companies; from single employee to hundreds of employees. Been active on computers since 7 years old, back in mid-80’s and have pioneered many facets of the internet and cyber security market we know today. Extensive government work experience from working with federal governments.” Continue reading →

Fintech Giant Fiserv Used Unclaimed Domain

March 17, 2021
77 Comments

If you sell Web-based software for a living and ship code that references an unregistered domain name, you are asking for trouble. But when the same mistake is made by a Fortune 500 company, the results can range from costly to disastrous. Here’s the story of one such goof committed by Fiserv [NASDAQ:FISV], a $15 billion firm that provides online banking software and other technology solutions to thousands of financial institutions.

In November 2020, KrebsOnSecurity heard from security researcher Abraham Vegh, who noticed something odd while inspecting an email from his financial institution.

Vegh could see the message from his bank referenced a curious domain: defaultinstitution.com. A quick search of WHOIS registration records showed the domain was unregistered. Wondering whether he might receive email communications to that address if he registered the domain, Vegh snapped it up for a few dollars, set up a catch-all email account for it, and waited.

“It appears that the domain is provided as a default, and customer bank IT departments are either assuming they don’t need to change it, or are not aware that they could/should,” Vegh said, noting that a malicious person who stumbled on his discovery earlier could have had a powerful, trusted domain from which to launch email phishing attacks.

At first, only a few wayward emails arrived. Ironically enough, one was from a “quality assurance” manager at Fiserv. The automatic reply message stated that the employee was out of the office “on R&R” and would be back to work on Dec. 14.

Many other emails poured in, including numerous “bounced” messages delivered in reply to missives from Cashedge.com, a money transfer service that Fiserv acquired in 2011.

Emails get bounced — or returned to the sender — when they are sent to an address that doesn’t exist or that is no longer active. The messages had been sent to an email address for a former client solutions director at Fiserv; the “reply-to:” address in those missives was “donotreply@defaultinstitution.com”.

The messages were informing customers of CashEdge’s main service Popmoney — which lets users send, request and receive money directly from bank accounts — that Popmoney was being replaced with Zelle, a more modern bank-to-bank transfer service.

Each CashEdge missive included information about recurring transfers that were being canceled, such as the plan ID, send date, amount to be transferred, the name and last four digits of the account number the money was coming from, and the email address of the recipient account.

Incredibly, at the bottom of every message to CashEdge/Popmoney customers was a boilerplate text: “This email was sent to [recipient name here]. If you have received this email in error, please send an e-mail to customersupport@defaultinstitution.com.”

Continue reading →

Can We Stop Pretending SMS Is Secure Now?

March 16, 2021
58 Comments

SMS text messages were already the weakest link securing just about anything online, mainly because there are tens of thousands of employees at mobile stores who can be tricked or bribed into swapping control over a mobile phone number to someone else. Now we’re learning about an entire ecosystem of companies that anyone could use to silently intercept text messages intended for other mobile users.

Security researcher “Lucky225” worked with Vice.com’s Joseph Cox to intercept Cox’s incoming text messages with his permission. Lucky225 showed how anyone could do the same after creating an account at a service called Sakari, a company that helps celebrities and businesses do SMS marketing and mass messaging.

The “how they did it” was sickeningly simple. It cost just $16, and there was precious little to prevent someone from stealing your text messages without your knowledge. Cox writes:

Sakari offers a free trial to anyone wishing to see what the company’s dashboard looks like. The cheapest plan, which allows customers to add a phone number they want to send and receive texts as, is where the $16 goes. Lucky225 provided Motherboard with screenshots of Sakari’s interface, which show a red “+” symbol where users can add a number.

While adding a number, Sakari provides the Letter of Authorization for the user to sign. Sakari’s LOA says that the user should not conduct any unlawful, harassing, or inappropriate behavior with the text messaging service and phone number.

But as Lucky225 showed, a user can just sign up with someone else’s number and receive their text messages instead.

Lucky225, who is chief information officer for Okey Systems, told KrebsOnSecurity that Sakari has since taken steps to block its service for being used with mobile telephone numbers. He said Sakari is just one part of a much larger, unregulated industry that can be used to hijack SMS messages for many phone numbers.

“It’s not a Sakari thing,” Lucky225 replied when first approached for more details. “It’s an industry-wide thing. There are many of these ‘SMS enablement’ providers.”

The most common way thieves hijack SMS messages these days involves “sim swapping,” a crime that entails bribing or tricking employees at wireless phone companies into modifying customer account information.

In a SIM swap, the attackers redirect the target’s phone number to a device they control, and then can intercept the target’s incoming SMS messages and phone calls. From there, the attacker can reset the password of any account which uses that phone number for password reset links.

But the attacks Lucky225 has been demonstrating merely require customers of any number of firms to sign a sworn “letter of authorization” or LOA stating that they indeed do have the authority to act on behalf of the owner of the targeted number.

Allison Nixon is chief research officer at Unit221B, a New York City-based cyber investigations firm. An expert on SIM-swapping attacks who’s been quoted quite a bit on this blog, Nixon said she also had Lucky225 test his interception tricks on her mobile phone, only to watch her incoming SMS messages show up on his burner phone.

“This basically means the only thing standing between anyone and the equivalent of a SIM swap is a forged LOA,” Nixon said. “And the ‘fix’ put in seems to be temporary in nature.”

The interception method that Lucky225 described is still dangerously exposed by a number of systemic weaknesses in the global SMS network, he said.

Most large and legacy telecommunications providers validate transfer requests related to their customers by consulting NPAC, or the Number Portability Administration Center. When customers want to move their phone numbers — mobile or otherwise — that request is routed through NPAC to the customer’s carrier.

That change request carries what’s known as an ALT-SPID, which is a four-digit number that enables NPAC to identify the telecommunications company currently providing service to the customer. More importantly, as part of this process no changes can happen unless the customer’s carrier has verified the changes with the existing customer.

But Lucky225 said the class of SMS interception he’s been testing targets a series of authentication weaknesses tied to a system developed by NetNumber, a private company in Lowell, Mass. NetNumber developed its own proprietary system for mapping telecommunications providers that is used by Sakari and an entire industry of similar firms.

NetNumber developed its six-digit ALT SPIDs (NetNumber IDs) to better organize and track communications service providers that were all using other numbering systems (and differing numbers of digits). But NetNumber also works directly with dozens of voice-over-IP or Internet-based phone companies which do not play by the same regulatory rules that apply to legacy telecommunications providers.

“There are many VoIP providers that offer ‘off net’ ‘text enablement’,” Lucky225 explained. “Companies such as ZipWhip that promise to let you ‘Text enable your existing business phone number’ so that customers can text your main business line whether it be VoIP, toll-free or a landline number.”

As Lucky225 wrote in his comprehensive Medium article, there are a plethora of wholesale VoIP providers that let you become a reseller with little to no verification, many of them allow blanket Letters of Authorization (LOAs), where you as the reseller promise that you have an LOA on file for any number you want to text enable for your resellers or end-users.

“In essence, once you have a reseller account with these VoIP wholesalers you can change the Net Number ID of any phone number to your wholesale provider’s NNID and begin receiving SMS text messages with virtually no authentication whatsoever. No SIM Swap, SS7 attacks, or port outs needed — just type the target’s phone number in a text box and hit submit and within minutes you can start receiving SMS text messages for them. They won’t even be alerted that anything has happened as their voice & data services will continue to work as usual. Surprisingly, despite the fact that I publicly disclosed this in 2018, nothing has been done to stop this relatively unsophisticated attack.”

Continue reading →