Posts Tagged: T-Mobile


18
May 18

T-Mobile Employee Made Unauthorized ‘SIM Swap’ to Steal Instagram Account

T-Mobile is investigating a retail store employee who allegedly made unauthorized changes to a subscriber’s account in an elaborate scheme to steal the customer’s three-letter Instagram username. The modifications, which could have let the rogue employee empty bank accounts associated with the targeted T-Mobile subscriber, were made even though the victim customer already had taken steps recommended by the mobile carrier to help minimize the risks of account takeover. Here’s what happened, and some tips on how you can protect yourself from a similar fate.

Earlier this month, KrebsOnSecurity heard from Paul Rosenzweig, a 27-year-old T-Mobile customer from Boston who had his wireless account briefly hijacked. Rosenzweig had previously adopted T-Mobile’s advice to customers about blocking mobile number port-out scams, an increasingly common scheme in which identity thieves armed with a fake ID in the name of a targeted customer show up at a retail store run by a different wireless provider and ask that the number to be transferred to the competing mobile company’s network.

So-called “port out” scams allow crooks to intercept your calls and messages while your phone goes dark. Porting a number to a new provider shuts off the phone of the original user, and forwards all calls to the new device. Once in control of the mobile number, thieves who have already stolen a target’s password(s) can request any second factor that is sent to the newly activated device, such as a one-time code sent via text message or or an automated call that reads the one-time code aloud.

In this case, however, the perpetrator didn’t try to port Rosenzweig’s phone number: Instead, the attacker called multiple T-Mobile retail stores within an hour’s drive of Rosenzweig’s home address until he succeeded in convincing a store employee to conduct what’s known as a “SIM swap.”

A SIM swap is a legitimate process by which a customer can request that a new SIM card (the tiny, removable chip in a mobile device that allows it to connect to the provider’s network) be added to the account. Customers can request a SIM swap when their existing SIM card has been damaged, or when they are switching to a different phone that requires a SIM card of another size.

However, thieves and other ne’er-do-wells can abuse this process by posing as a targeted mobile customer or technician and tricking employees at the mobile provider into swapping in a new SIM card for that customer on a device that they control. If successful, the SIM swap accomplishes more or less the same result as a number port out (at least in the short term) — effectively giving the attackers access to any text messages or phone calls that are sent to the target’s mobile account.

Rosenzweig said the first inkling he had that something wasn’t right with his phone was on the evening of May 2, 2018, when he spotted an automated email from Instagram. The message said the email address tied to the three-letter account he’d had on the social media platform for seven years — instagram.com/par — had been changed. He quickly logged in to his Instagram account, changed his password and then reverted the email on the account back to his original address.

By this time, the SIM swap conducted by the attacker had already been carried out, although Rosenzweig said he didn’t notice his phone displaying zero bars and no connection to T-Mobile at the time because he was at home and happily surfing the Web on his device using his own wireless network.

The following morning, Rosenzweig received another notice — this one from Snapchat — stating that the password for his account there (“p9r”) had been changed. He subsequently reset the Instagram password and then enabled two factor authentication on his Snapchat account.

“That was when I realized my phone had no bars,” he recalled. “My phone was dead. I couldn’t even call 611,” [the mobile short number that all major wireless providers make available to reach their customer service departments].”

It appears that the perpetrator of the SIM swap abused not only internal knowledge of T-Mobile’s systems, but also a lax password reset process at Instagram. The social network allows users to enable notifications on their mobile phone when password resets or other changes are requested on the account.

But this isn’t exactly two-factor authentication because it also lets users reset their passwords via their mobile account by requesting a password reset link to be sent to their mobile device. Thus, if someone is in control of your mobile phone account, they can reset your Instagram password (and probably a bunch of other types of accounts).

Rosenzweig said even though he was able to reset his Instagram password and restore his old email address tied to the account, the damage was already done: All of his images and other content he’d shared on Instagram over the years was still tied to his account, but the attacker had succeeded in stealing his “par” username, leaving him with a slightly less sexy “par54384321,” (apparently chosen for him at random by either Instagram or the attacker). Continue reading →


17
May 18

Tracking Firm LocationSmart Leaked Location Data for Customers of All Major U.S. Mobile Carriers Without Consent in Real Time Via Its Web Site

LocationSmart, a U.S. based company that acts as an aggregator of real-time data about the precise location of mobile phone devices, has been leaking this information to anyone via a buggy component of its Web site — without the need for any password or other form of authentication or authorization — KrebsOnSecurity has learned. The company took the vulnerable service offline early this afternoon after being contacted by KrebsOnSecurity, which verified that it could be used to reveal the location of any AT&T, Sprint, T-Mobile or Verizon phone in the United States to an accuracy of within a few hundred yards.

On May 10, The New York Times broke the news that a different cell phone location tracking company called Securus Technologies had been selling or giving away location data on customers of virtually any major mobile network provider to a sheriff’s office in Mississippi County, Mo.

On May 15, ZDnet.com ran a piece saying that Securus was getting its data through an intermediary — Carlsbad, CA-based LocationSmart.

Wednesday afternoon Motherboard published another bombshell: A hacker had broken into the servers of Securus and stolen 2,800 usernames, email addresses, phone numbers and hashed passwords of authorized Securus users. Most of the stolen credentials reportedly belonged to law enforcement officers across the country — stretching from 2011 up to this year.

Several hours before the Motherboard story went live, KrebsOnSecurity heard from Robert Xiao, a security researcher at Carnegie Mellon University who’d read the coverage of Securus and LocationSmart and had been poking around a demo tool that LocationSmart makes available on its Web site for potential customers to try out its mobile location technology.

LocationSmart’s demo is a free service that allows anyone to see the approximate location of their own mobile phone, just by entering their name, email address and phone number into a form on the site. LocationSmart then texts the phone number supplied by the user and requests permission to ping that device’s nearest cellular network tower.

Once that consent is obtained, LocationSmart texts the subscriber their approximate longitude and latitude, plotting the coordinates on a Google Street View map. [It also potentially collects and stores a great deal of technical data about your mobile device. For example, according to their privacy policy that information “may include, but is not limited to, device latitude/longitude, accuracy, heading, speed, and altitude, cell tower, Wi-Fi access point, or IP address information”].

But according to Xiao, a PhD candidate at CMU’s Human-Computer Interaction Institute, this same service failed to perform basic checks to prevent anonymous and unauthorized queries. Translation: Anyone with a modicum of knowledge about how Web sites work could abuse the LocationSmart demo site to figure out how to conduct mobile number location lookups at will, all without ever having to supply a password or other credentials.

“I stumbled upon this almost by accident, and it wasn’t terribly hard to do,” Xiao said. “This is something anyone could discover with minimal effort. And the gist of it is I can track most peoples’ cell phone without their consent.”

Xiao said his tests showed he could reliably query LocationSmart’s service to ping the cell phone tower closest to a subscriber’s mobile device. Xiao said he checked the mobile number of a friend several times over a few minutes while that friend was moving and found he was then able to plug the coordinates into Google Maps and track the friend’s directional movement.

“This is really creepy stuff,” Xiao said, adding that he’d also successfully tested the vulnerable service against one Telus Mobility mobile customer in Canada who volunteered to be found.

Before LocationSmart’s demo was taken offline today, KrebsOnSecurity pinged five different trusted sources, all of whom gave consent to have Xiao determine the whereabouts of their cell phones. Xiao was able to determine within a few seconds of querying the public LocationSmart service the near-exact location of the mobile phone belonging to all five of my sources.

LocationSmart’s demo page.

One of those sources said the longitude and latitude returned by Xiao’s queries came within 100 yards of their then-current location. Another source said the location found by the researcher was 1.5 miles away from his current location. The remaining three sources said the location returned for their phones was between approximately 1/5 to 1/3 of a mile at the time.

Reached for comment via phone, LocationSmart Founder and CEO Mario Proietti said the company was investigating.

“We don’t give away data,” Proietti said. “We make it available for legitimate and authorized purposes. It’s based on legitimate and authorized use of location data that only takes place on consent. We take privacy seriously and we’ll review all facts and look into them.”

LocationSmart’s home page features the corporate logos of all four the major wireless providers, as well as companies like Google, Neustar, ThreatMetrix, and U.S. Cellular. The company says its technologies help businesses keep track of remote employees and corporate assets, and that it helps mobile advertisers and marketers serve consumers with “geo-relevant promotions.”

LocationSmart’s home page lists many partners.

It’s not clear exactly how long LocationSmart has offered its demo service or for how long the service has been so permissive; this link from archive.org suggests it dates back to at least January 2017. This link from The Internet Archive suggests the service may have existed under a different company name — loc-aid.com — since mid-2011, but it’s unclear if that service used the same code. Loc-aid.com is one of four other sites hosted on the same server as locationsmart.com, according to Domaintools.com. Continue reading →


28
Feb 18

How to Fight Mobile Number Port-out Scams

T-Mobile, AT&T and other mobile carriers are reminding customers to take advantage of free services that can block identity thieves from easily “porting” your mobile number out to another provider, which allows crooks to intercept your calls and messages while your phone goes dark. Tips for minimizing the risk of number porting fraud are available below for customers of all four major mobile providers, including Sprint and Verizon.

Unauthorized mobile phone number porting is not a new problem, but T-Mobile said it began alerting customers about it earlier this month because the company has seen a recent uptick in fraudulent requests to have customer phone numbers ported over to another mobile provider’s network.

“We have been alerting customers via SMS that our industry is experiencing a phone number port out scam that could impact them,” T-Mobile said in a written statement. “We have been encouraging them to add a port validation feature, if they’ve not already done so.”

Crooks typically use phony number porting requests when they have already stolen the password for a customer account (either for the mobile provider’s network or for another site), and wish to intercept the one-time password that many companies send to the mobile device to perform two-factor authentication.

Porting a number to a new provider shuts off the phone of the original user, and forwards all calls to the new device. Once in control of the mobile number, thieves can request any second factor that is sent to the newly activated device, such as a one-time code sent via text message or or an automated call that reads the one-time code aloud.

In these cases, the fraudsters can call a customer service specialist at a mobile provider and pose as the target, providing the mark’s static identifiers like name, date of birth, social security number and other information. Often this is enough to have a target’s calls temporarily forwarded to another number, or ported to a different provider’s network.

Port out fraud has been an industry problem for a long time, but recently we’ve seen an uptick in this illegal activity,” T-Mobile said.  “We’re not providing specific metrics, but it’s been enough that we felt it was important to encourage customers to add extra security features to their accounts.”

In a blog post published Tuesday, AT&T said bad guys sometimes use illegal porting to steal your phone number, transfer the number to a device they control and intercept text authentication messages from your bank, credit card issuer or other companies.

“You may not know this has happened until you notice your mobile device has lost service,” reads a post by Brian Rexroad, VP of security relations at AT&T. “Then, you may notice loss of access to important accounts as the attacker changes passwords, steals your money, and gains access to other pieces of your personal information.”

Rexroad says in some cases the thieves just walk into an AT&T store and present a fake ID and your personal information, requesting to switch carriers. Porting allows customers to take their phone number with them when they change phone carriers.

The law requires carriers to provide this number porting feature, but there are ways to reduce the risk of this happening to you. Continue reading →


27
Jul 17

Gas Pump Skimmer Sends Card Data Via Text

Skimming devices that crooks install inside fuel station gas pumps frequently rely on an embedded Bluetooth component allowing thieves to collect stolen credit card data from the pumps wirelessly with any mobile device. The downside of this approach is that Bluetooth-based skimmers can be detected by anyone else with a mobile device. Now, investigators in the New York say they are starting to see pump skimmers that use cannibalized cell phone components to send stolen card data via text message.

Skimmers that transmit stolen card data wirelessly via GSM text messages and other mobile-based communications methods are not new; they have been present — if not prevalent — in ATM skimming devices for ages.

But this is the first instance KrebsOnSecurity is aware of in which such SMS skimmers have been found inside gas pumps, and that matches the experience of several states hardest hit by pump skimming activity.

The beauty of the GSM-based skimmer is that it can transmit stolen card data wirelessly via text message, meaning thieves can receive real-time transmissions of the card data anywhere in the world — never needing to return to the scene of the crime. That data can then be turned into counterfeit physical copies of the cards.

Here’s a look at a new skimmer pulled from compromised gas pumps at three different filling stations in New York this month. Like other pump skimmers, this device was hooked up to the pump’s internal power, allowing it to operate indefinitely without relying on batteries.

A GSM-based card skimmer found embedded in a gas pump in the northeastern United States.

A GSM-based card skimmer found embedded in a gas pump in the northeastern United States.

It may be difficult to see from the picture above, but the skimmer includes a GSM-based device with a SIM card produced by cellular operator T-Mobile. The image below shows the other side of the pump skimmer, with the SIM card visible in the upper right corner of the circuitboard:

The reverse side of this GSM-based pump skimmer shows a SIM card from T-Mobile.

The reverse side of this GSM-based pump skimmer shows a SIM card from T-Mobile.

It’s not clear what type of mobile device was used in this skimmer, and the police officer who shared these images with KrebsOnSecurity said the forensic analysis of the device was ongoing. Continue reading →


18
Jul 11

Is Your Voicemail Wide Open?

The “phone-hacking” scandal that has gripped the U.K. is now making waves on this side of the pond. It stems from an alleged series of intrusions into the wireless voicemail boxes of high profile celebrities and 9/11 victims. The news stories about this scandal make it sound as if the attacks were sophisticated — an investigation into exactly what happened is still pending — but many people would be surprised to learn just how easy it is to “hack” into someone’s voicemail.

For years, it has been a poorly-kept secret that some of the world’s largest wireless providers rely on caller ID information to verify that a call to check voicemail is made from the account holder’s mobile phone. Unfortunately, this means that if you haven’t set up your voicemail account to require a PIN for access, your messages may be vulnerable to snooping by anyone who has access to caller ID “spoofing” technology. Several companies offer caller ID spoofing services, and the tools needed to start your own spoofing operation are freely available online.

I wanted to check whether this is possible with my AT&T account — so I chose my wife’s new iPhone as the target; I was reasonably sure she hadn’t set a PIN on her voicemail. I surfed over to spooftel.com and found that I still had $10 in credits in my account. I instructed Spooftel to call her number, and to use that same number as the caller ID information that gets transmitted to my wife’s phone. Her phone rang 4 times before going to voicemail; I pressed the # sign on my iPhone and was immediately presented with her saved messages. Continue reading →