Posts Tagged: twofactorauth.org


29
Aug 18

Instagram’s New Security Tools are a Welcome Step, But Not Enough

Instagram users should soon have more secure options for protecting their accounts against Internet bad guys.  On Tuesday, the Facebook-owned social network said it is in the process of rolling out support for third-party authentication apps. Unfortunately, this welcome new security offering does nothing to block Instagram account takeovers when thieves manage to hijack a target’s mobile phone number — an increasingly common crime.

New two-factor authentication options Instagram says it is rolling out to users over the next few weeks.

For years, security experts have warned that hackers are exploiting weak authentication at Instagram to commandeer accounts. Instagram has long offered users a security option to have a one-time code sent via text message to a mobile device, but these codes can be intercepted via several methods (more on that in a bit).

The new authentication offering requires users to download a third-party app like Authy, Duo or Google Authenticator, which generates a one-time code that needs to be entered after the user supplies a password.

In a blog post Tuesday, Instagram said support for third-party authenticator apps “has begun to roll out and will be available to the global community in the coming weeks.

Instagram put me on a whitelist of accounts to get an early peek at the new security feature, so these options probably aren’t yet available to most users. But there’s a screenshot below that shows the multi-factor options available in the mobile app. When these options do become more widely available, Instagram says people can use a third-party app to receive a one-time code. To do this:

  1. Go to your Settings.
  2. Scroll down and tap Two-Factor Authentication.
  3. If you haven’t already turned two-factor authentication on, tap Get Started.
  4. Tap next to Authentication App, then follow the on-screen instructions.
  5. Enter the confirmation code from the third party authentication app to complete the process.

Note that if you have previously enabled SMS-based authentication, it is likely still enabled unless and until you disable it. The app also prompts users to save a series of recovery codes, which should be kept in a safe place in case one’s mobile device is ever lost.

WHAT IT DOESN’T FIX

Instagram has received quite a lot of bad press lately from publications reporting numerous people who had their accounts hijacked even though they had Instagram’s SMS authentication turned on. The thing is, many of those stories have been about people having their Instagram accounts hijacked because fraudsters were able to hijack their mobile phone number.

In these cases, the fraudsters were able to hijack the Instagram accounts because Instagram allows users to reset their account passwords with a single factor — using nothing more than a text message sent to a mobile number on fileAnd nothing in these new authentication offerings will change that for people who have shared their mobile number with Instagram.

Criminals can and do exploit SMS-based password reset requests to hijack Instagram accounts by executing unauthorized “SIM swaps,” i.e., tricking the target’s mobile provider into transferring the phone number to a device or account they control and intercepting the password reset link sent via SMS. Once they hijack the target’s mobile number, they can then reset the password for the associated Instagram account.

I asked Instagram if there was any way for people who have supplied the company with their phone number to turn off SMS-based password reset requests. I received this response from their PR folks:

“I can confirm that disabling SMS two factor will not disable the ability to reset a password via SMS,” a spokesperson said via email. “We recommend that the community use a third-party app for authentication, in place of SMS authentication. We’ll continue to iterate and improve on this product to keep people safe on our platform.” Continue reading →


1
Aug 18

Reddit Breach Highlights Limits of SMS-Based Authentication

Reddit.com today disclosed that a data breach exposed some internal data, as well as email addresses and passwords for some Reddit users. As Web site breaches go, this one doesn’t seem too severe. What’s interesting about the incident is that it showcases once again why relying on mobile text messages (SMS) for two-factor authentication (2FA) can lull companies and end users into a false sense of security.

In a post to Reddit, the social news aggregation platform said it learned on June 19 that between June 14 and 18 an attacker compromised a several employee accounts at its cloud and source code hosting providers.

Reddit said the exposed data included internal source code as well as email addresses and obfuscated passwords for all Reddit users who registered accounts on the site prior to May 2007. The incident also exposed the email addresses of some users who had signed up to receive daily email digests of specific discussion threads.

Of particular note is that although the Reddit employee accounts tied to the breach were protected by SMS-based two-factor authentication, the intruder(s) managed to intercept that second factor.

“Already having our primary access points for code and infrastructure behind strong authentication requiring two factor authentication (2FA), we learned that SMS-based authentication is not nearly as secure as we would hope, and the main attack was via SMS intercept,” Reddit disclosed. “We point this out to encourage everyone here to move to token-based 2FA.”

Reddit didn’t specify how the SMS code was stolen, although it did say the intruders did not hack Reddit employees’ phones directly. Nevertheless, there are a variety of well established ways that attackers can intercept one-time codes sent via text message.

In one common scenario, known as a SIM-swap, the attacker masquerading as the target tricks the target’s mobile provider into tying the customer’s service to a new SIM card that the bad guys control. A SIM card is the tiny, removable chip in a mobile device that allows it to connect to the provider’s network. 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.

Another typical scheme involves mobile number port-out scams, wherein the attacker impersonates a customer and requests that the customer’s mobile number be transferred to another mobile network provider. In both port-out and SIM swap schemes, the victim’s phone service gets shut off and any one-time codes delivered by SMS (or automated phone call) get sent to a device that the attackers control. Continue reading →


5
Jun 18

Researcher Finds Credentials for 92 Million Users of DNA Testing Firm MyHeritage

MyHeritage, an Israeli-based genealogy and DNA testing company, disclosed today that a security researcher found on the Internet a file containing the email addresses and hashed passwords of more than 92 million of its users.

MyHeritage says it has no reason to believe other user data was compromised, and it is urging all users to change their passwords. It says sensitive customer DNA data is stored on IT systems that are separate from its user database, and that user passwords were “hashed” — or churned through a mathematical model designed to turn them into unique pieces of gibberish text that is (in theory, at least) difficult to reverse.

MyHeritage did not say in its blog post which method it used to obfuscate user passwords, but suggested that it had added some uniqueness to each password (beyond the hashing) to make them all much harder to crack.

“MyHeritage does not store user passwords, but rather a one-way hash of each password, in which the hash key differs for each customer,” wrote Omer Deutsch, MyHeritage’s chief information security officer. “This means that anyone gaining access to the hashed passwords does not have the actual passwords.”

The company said the security researcher who found the user database reported it on Monday, June 4. The file contained the email addresses and hashed passwords of 92,283,889 users who created accounts at MyHeritage up to and including Oct. 26, 2017, which MyHeritage says was “the date of the breach.”

MyHeritage added that it is expediting work on an upcoming two-factor authentication option that the company plans to make available to all MyHeritage users soon.

“This will allow users interested in taking advantage of it, to authenticate themselves using a mobile device in addition to a password, which will further harden their MyHeritage accounts against illegitimate access,” the blog post concludes.

MyHeritage has not yet responded to requests for comment and clarification on several points. I will update this post if that changes. Continue reading →


18
Dec 17

The Market for Stolen Account Credentials

Past stories here have explored the myriad criminal uses of a hacked computer, the various ways that your inbox can be spliced and diced to help cybercrooks ply their trade, and the value of a hacked company. Today’s post looks at the price of stolen credentials for just about any e-commerce, bank site or popular online service, and provides a glimpse into the fortunes that an enterprising credential thief can earn selling these accounts on consignment.

Not long ago in Internet time, your typical cybercriminal looking for access to a specific password-protected Web site would most likely visit an underground forum and ping one of several miscreants who routinely leased access to their “bot logs.”

These bot log sellers were essentially criminals who ran large botnets (collections of hacked PCs) powered by malware that can snarf any passwords stored in the victim’s Web browser or credentials submitted into a Web-based login form. For a few dollars in virtual currency, a ne’er-do-well could buy access to these logs, or else he and the botmaster would agree in advance upon a price for any specific account credentials sought by the buyer.

Back then, most of the stolen credentials that a botmaster might have in his possession typically went unused or unsold (aside from the occasional bank login that led to a juicy high-value account). Indeed, these plentiful commodities held by the botmaster for the most part were simply not a super profitable line of business and so went largely wasted, like bits of digital detritus left on the cutting room floor.

But oh, how times have changed! With dozens of sites in the underground now competing to purchase and resell credentials for a variety of online locations, it has never been easier for a botmaster to earn a handsome living based solely on the sale of stolen usernames and passwords alone.

If the old adage about a picture being worth a thousand words is true, the one directly below is priceless because it illustrates just how profitable the credential resale business has become.

This screen shot shows the earnings panel of a crook who sells stolen credentials for hundreds of Web sites to a dark web service that resells them. This botmaster only gets paid when someone buys one of his credentials. So far this year, customers of this service have purchased more than 35,000 credentials he’s sold to this service, earning him more than $288,000 in just a few months.

The image shown above is the wholesaler division of “Carder’s Paradise,” a bustling dark web service that sells credentials for hundreds of popular Web destinations. The screen shot above is an earnings panel akin to what you would see if you were a seller of stolen credentials to this service — hence the designation “Seller’s Paradise” in the upper left hand corner of the screen shot.

This screen shot was taken from the logged-in account belonging to one of the more successful vendors at Carder’s Paradise. We can see that in just the first seven months of 2017, this botmaster sold approximately 35,000 credential pairs via the Carder’s Paradise market, earning him more than $288,000. That’s an average of $8.19 for each credential sold through the service.

Bear in mind that this botmaster only makes money based on consignment: Regardless of how much he uploads to Seller’s Paradise, he doesn’t get paid for any of it unless a Carder’s Paradise customer chooses to buy what he’s selling.

Fortunately for this guy, almost 9,000 different customers of Carder’s Paradise chose to purchase one or more of his username and password pairs. It was not possible to tell from this seller’s account how many credential pairs total that he has contributed to this service which went unsold, but it’s a safe bet that it was far more than 35,000.

[A side note is in order here because there is some delicious irony in the backstory behind the screenshot above: The only reason a source of mine was able to share it with me was because this particular seller re-used the same email address and password across multiple unrelated cybercrime services]. Continue reading →


5
Jan 17

Stolen Passwords Fuel Cardless ATM Fraud

Some financial institutions are now offering so-called “cardless ATM” transactions that allow customers to withdraw cash using nothing more than their mobile phones. But as the following story illustrates, this new technology also creates an avenue for thieves to quickly and quietly convert stolen customer bank account usernames and passwords into cold hard cash. Worse still, fraudulent cardless ATM withdrawals may prove more difficult for customers to dispute because they place the victim at the scene of the crime.

A portion of the third rejection letter that Markula received from Chase about her $2,900 fraud claim. The bank ultimately reversed itself and refunded the money after being contacted by KrebsOnsecurity, stating that Markula's account was one of several that were pilfered by a crime gang that has since been arrested by authorities.

A portion of the third rejection letter that Markula received from Chase about her $2,900 fraud claim.

San Francisco resident Kristina Markula told KrebsOnSecurity that it wasn’t until shortly after a vacation in Cancun, Mexico in early November 2016 that she first learned that Chase Bank even offered cardless ATM access. Markula said that while she was still in Mexico she tried to view her bank balance using a Chase app on her smartphone, but that the app blocked her from accessing her account.

Markula said she thought at the time that Chase had blocked her from using the app because the request came from an unusual location. After all, she didn’t have an international calling or data plan and was trying to access the account via Wi-Fi at her hotel in Mexico.

Upon returning to the United States, Markula called the number on the back of her card and was told she needed to visit the nearest Chase bank branch and present two forms of identification. At a Chase branch in San Francisco, she handed the teller a California driver’s license and her passport. The branch manager told her that someone had used her Chase online banking username and password to add a new mobile phone number to her account, and then move $2,900 from her savings to her checking account.

The manager told Markula that whoever made the change then requested that a new mobile device be added to the account, and changed the contact email address for the account. Very soon after, that same new mobile device was used to withdraw $2,900 in cash from her checking account at the Chase Bank ATM in Pembroke Pines, Fla.

A handful of U.S. banks, including Chase, have deployed ATMs that are capable of dispensing cash without requiring an ATM card. In the case of Chase ATMs, the customer approaches the cash machine with a smart phone that is already associated with a Chase account. Associating an account with the mobile app merely requires the customer to supply the app with their online banking username and password.

Users then tell the Chase app how much they want to withdraw, and the app creates a unique 7-digit code that needs to be entered at the Chase ATM (instead of numeric code, some banks offering cardless ATM withdrawals will have the app display a QR code that needs to be read by a scanner on the ATM). Assuming the code checks out, the machine dispenses the requested cash and the transaction is complete. At no time is the Chase customer asked to enter his or her 4-digit ATM card PIN.

Most financial institutions will limit traditional ATM customers to withdrawing $300-$600 per transaction, but some banks have set cardless transaction limits at much higher amounts under certain circumstances. For example, at the time Markula’s fraud occurred, the limit was set at $3,000 for withdrawals during normal bank business hours and made at Chase ATMs located at Chase branches.

Markula said the bank employees helped her close the account and file a claim to dispute the withdrawal. She said the teller and the bank manager reviewed her passport and confirmed that the disputed transaction took place during the time between which her passport was stamped by U.S. and Mexican immigration authorities. However, Markula said Chase repeatedly denied her claims.

“We wanted to thank you for providing your information while we thoroughly researched your dispute,” Chase’s customer claims department wrote in the third rejection letter sent to Markula, dated January 5, 2017. “We confirmed that the disputed charges were correct and we will not be making an adjustment to your account.”

Markula said she was dumbfounded by the rejection letter because the last time she spoke with a fraud claims manager at Chase, the manager told her that the transaction had all of the hallmarks of an account takeover.

“I’m pretty frustrated at the process so far,” said Markula, who shared with this author a detailed timeline of events before and after the disputed transaction. “Not captured in this timeline are the countless phone calls to the fraud department which is routed overseas. The time it takes to reach someone and poor communication seems designed to make one want to give up.”

KrebsOnSecurity contacted Chase today about Markula’s case. Chase spokesman Mike Fusco said Markula’s rejection letter was incorrect, and that further investigation revealed she had been victimized by a group of a half-dozen fraudsters who were caught using the above-described technique to empty out Chase bank accounts.

Fusco forwarded this author a link to a Fox28 story about six men from Miami, Fla. who were arrested late last year in Columbus, Ohio in connection with what authorities there called a “multi-state crime spree” targeting Chase accounts. Continue reading →


7
Sep 16

The Limits of SMS for 2-Factor Authentication

A recent ping from a reader reminded me that I’ve been meaning to blog about the security limitations of using cell phone text messages for two-factor authentication online. The reader’s daughter had received a text message claiming to be from Google, warning that her Gmail account had been locked because someone in India had tried to access her account. The young woman was advised to expect a 6-digit verification code to be sent to her and to reply to the scammer’s message with that code.

2faMark Cobb, a computer technician in Reno, Nev., said had his daughter fallen for the ruse, her Gmail account would indeed have been completely compromised, and she really would have been locked out of her account because the crooks would have changed her password straight away.

Cobb’s daughter received the scam text message because she’d enabled 2-factor authentication on her Gmail account, selecting the option to have Google request that she enter a 6-digit code texted to her cell phone each time it detects a login from an unknown computer or location (in practice, the code is to be entered on the Gmail site, not sent in any kind of texted or emailed reply).

In this case, the thieves already had her password — most likely because she re-used it on some other site that got hacked. Cobb says he and his daughter believe her mobile number and password may have been exposed as part of the 2012 breach at LinkedIn.

In any case, the crooks were priming her to expect a code and to repeat it back to them because that code was the only thing standing in the way of their seizing control over her account. And they could control when Google would send the code to her phone because Google would do this as soon as they tried to log in using her username and password. Indeed, the timing aspect of this attack helps make it more believable to the target.

This is a fairly clever — if not novel — attack, and it’s one I’d wager would likely fool a decent percentage of users who have enabled text messages as a form of two-factor authentication. Certainly, text messaging is far from the strongest form of 2-factor authentication, but it is better than allowing a login with nothing more than a username and password, as this scam illustrates.

Nevertheless, text messaging codes to users isn’t the safest way to do two-factor authentication, even if some entities — like the U.S. Social Security Administration and Sony’s Playstation network — are just getting around to offering two-factor via SMS.

But don’t take my word for it. That’s according to the National Institute of Standards and Technology (NIST), which recently issued new proposed digital authentication guidelines urging organizations to favor other forms of two-factor — such as time-base one-time passwords generated by mobile apps — over text messaging. By the way, NIST is seeking feedback on these recommendations.

If anyone’s interested, Sophos’s Naked Security blog has a very readable breakdown of what’s new in the NIST guidelines. Among my favorite highlights is this broad directive: Favor the user.

“To begin with, make your password policies user friendly and put the burden on the verifier when possible,” Sophos’s Chester Wisniewski writes. “In other words, we need to stop asking users to do things that aren’t actually improving security.” Like expiring passwords and making users change them frequently, for example.

Okay, so the geeks-in-chief are saying it’s time to move away from texting as a form of 2-factor authentication. And, of course, they’re right, because text messages are a lot like email, in that it’s difficult to tell who really sent the message, and the message itself is sent in plain text — i.e. is readable by anyone who happens to be lurking in the middle.

But security experts and many technology enthusiasts have a tendency to think that everyone should see the world through the lens of security, whereas most mere mortal users just want to get on with their lives and are perfectly content to use the same password across multiple sites — regardless of how many times they’re told not to do so. Continue reading →


6
Nov 15

FCC Fines Cox $595K Over Lizard Squad Hack

In September 2014, I penned a column called “We Take Your Privacy and Security. Seriously.” It recounted my experience receiving notice from my former Internet service provider — Cox Communications — that a customer service employee had been tricked into giving away my personal information to hackers. This week, the Federal Communications Commission (FCC) fined Cox $595,000 for the incident that affected me and 60 other customers.

coxletterI suspected, but couldn’t prove at the time, that the band of teenage cybercriminals known as the Lizard Squad was behind the attack. According to a press release issued Thursday by the FCC, the intrusion began after LizardSquad member “Evil Jordie” phoned up Cox support pretending to be from the company’s IT department, and convinced both a Cox customer service representative and Cox contractor to enter their account IDs and passwords into a fake, or “phishing,” website.

“With those credentials, the hacker gained unauthorized access to Cox customers’ personally identifiable information, which included names, addresses, email addresses, secret questions/answers, PIN, and in some cases partial Social Security and driver’s license numbers of Cox’s cable customers, as well as Customer Proprietary Network Information (CPNI) of the company’s telephone customers,” the FCC said. “The hacker then posted some customers’ information on social media sites, changed some customers’ account passwords, and shared the compromised account credentials with another alleged member of the Lizard Squad.”

My September 2014 column took Cox to task for not requiring two-step authentication for employees: Had the company done so, this phishing attack probably would have failed. As a condition of the settlement with the FCC, the commission said Cox has agreed to adopt a comprehensive compliance plan, which establishes an information security program that includes annual system audits, internal threat monitoring, penetration testing, and additional breach notification systems and processes to protect customers’ personal information, and the FCC will monitor Cox’s compliance with the consent decree for seven years. Continue reading →