On Feb. 21, 2019, KrebsOnSecurity contacted Italian restaurant chain Buca di Beppo after discovering strong evidence that two million credit and debit card numbers belonging to the company’s customers were being sold in the cybercrime underground. Today, Buca’s parent firm announced it had remediated a 10-month breach of its payment systems at dozens of restaurants, including some locations of its other brands such as Earl of Sandwich and Planet Hollywood.

In a statement posted to its Web site today, Orlando, Fla. based hospitality firm Earl Enterprises said a data breach involving malware installed on its point-of-sale systems allowed cyber thieves to steal card details from customers between May 23, 2018 and March 18, 2019.

Earl Enterprises did not respond to requests for specifics about how many customers total may have been impacted by the 10-month breach. The company’s statement directs concerned customers to an online tool that allows one to look up breached locations by city and state.

According to an analysis of that page, it appears the breach impacts virtually all 67 Buca di Beppo locations in the United States; a handful out of the total 31 Earl of Sandwich locations; and Planet Hollywood locations in Las Vegas, New York City and Orlando. Also impacted were Tequila Taqueria in Las Vegas; Chicken Guy! in Disney Springs, Fla.; and Mixology in Los Angeles.

KrebsOnsecurity contacted the executive team at Buca di Beppo in late February after determining most of this restaurant’s locations were likely involved a data breach that first surfaced on Joker’s Stash, an underground shop that sells huge new batches of freshly-stolen credit and debit cards on a regular basis.

Joker’s Stash typically organizes different batches of stolen cards around a codename tied to a specific merchant breach. This naming convention allows criminals who purchased cards from a specific batch and found success using those cards fraudulently to buy from the same batch again when future cards stolen from the same breached merchant are posted for sale.

While a given batch’s nickname usually has little relation to the breached merchant, Joker’s Stash does offer a number of search options for customers that can sometimes be used to trace a large batch of stolen cards back to a specific merchant.

This is especially true if the victim merchant has a number of store locations in multiple smaller U.S. towns. That’s because while Joker’s Stash makes its stolen cards searchable via a variety of qualities — the card-issuing bank or expiration date, for example — perhaps the most useful in this case is the city or ZIP code tied to each card.

As with a number of other carding sites, Joker’s Stash indexes cards by the city and/or ZIP code of the store from which the card was stolen (not the ZIP code of the affected cardholders).

On Feb. 20, Joker’s Stash moved a new batch of some 2.15 million stolen cards that it dubbed the “Davinci Breach.” An analysis of the cities and towns listed among the Davinci cards for sale included a number of hacked store locations that were not in major cities, such as Burnsville, Minn., Levonia, Mich., Midvale, Utah, Norwood, Ohio, and Wheeling, Ill.

Earl Enterprises said in its statement the malicious software installed at affected stores captured payment card data, which could have included credit and debit card numbers, expiration dates and, in some cases, cardholder names. The company says online orders were not affected.

Malicious hackers typically steal card data from organizations by hacking into point-of-sale systems remotely and seeding those systems with malicious software that can copy account data stored on a card’s magnetic stripe. Thieves can use that data to clone the cards and then use the counterfeits to buy high-priced merchandise from electronics stores and big box retailers.

Cardholders are not responsible for fraudulent charges, but your bank isn’t always going to detect card fraud. That’s why it’s important to regularly review your monthly statements and quickly report any unauthorized charges.

In 2013, the FBI exploited a zero-day vulnerability in Firefox to seize control over a Dark Web network of child pornography sites. The alleged owner of that ring – 33-year-old Freedom Hosting operator Eric Eoin Marques – was arrested in Ireland later that year on a U.S. warrant and has been in custody ever since. This week, Ireland’s Supreme Court cleared the way for Marques to be extradited to the United States.

The FBI has called Marques the world’s largest facilitator of child porn. He is wanted on four charges linked to hidden child porn sites like “Lolita City” and “PedoEmpire,” which the government says were extremely violent, graphic and depicting the rape and torture of pre-pubescent children. Investigators allege that sites on Freedom Hosting had thousands of customers, and earned Marques more than $1.5 million.

For years Freedom Hosting had developed a reputation as a safe haven for hosting child porn. Marques allegedly operated Freedom Hosting as a turnkey solution for Web sites that hide their true location using Tor, an online anonymity tool.

The sites could only be accessed using the Tor Browser Bundle, which is built on the Firefox Web browser. On Aug. 4, 2013, U.S. federal agents exploited a previously unknown vulnerability in Firefox version 17 that allowed them to identify the true Internet addresses and computer names of people using Tor Browser to visit the child porn sites at Freedom Hosting.

Irish public media service RTE reported in 2013 that Marques briefly regained access to one of his hosting servers even after the FBI had seized control over it and changed the password, briefly locking the feds out of the system.

As Wired.com observed at the time, “in addition to the wrestling match over Freedom Hosting’s servers, Marques allegedly dove for his laptop when the police raided him, in an effort to shut it down.”

Marques, who holds dual Irish-US citizenship, was denied bail and held pending his nearly six-year appeal process to contest his extradition. FBI investigators told the courts they feared he would try to destroy evidence and/or flee the country. FBI agents testified that Marques had made inquiries about how to get a visa and entry into Russia and set up residence and citizenship there.

“My suspicion is he was trying to look for a place to reside to make it the most difficult to be extradited to the US,” FBI Special Agent Brooke Donahue reportedly told an Irish court in 2013.

Even before the FBI testified in court about its actions, clues began to emerge that the Firefox exploit used to record the true Internet address of Freedom Hosting visitors was developed specifically for U.S. federal investigators. In an analysis posted on Aug. 4, reverse engineer Vlad Tsrklevich concluded that because the payload of the Firefox exploit didn’t download or execute any secondary backdoor or commands “it’s very likely that this is being operated by an [law enforcement agency] and not by blackhats.”

According to The Irish Times, in a few days Marques is likely to be escorted from Cloverhill Prison to Dublin Airport where he will be put on a US-bound flight and handcuffed to a waiting US marshal. If convicted of all four charges, he faces life in prison (3o years for each count).

Hundreds of millions of Facebook users had their account passwords stored in plain text and searchable by thousands of Facebook employees — in some cases going back to 2012, KrebsOnSecurity has learned. Facebook says an ongoing investigation has so far found no indication that employees have abused access to this data.

Facebook is probing a series of security failures in which employees built applications that logged unencrypted password data for Facebook users and stored it in plain text on internal company servers. That’s according to a senior Facebook employee who is familiar with the investigation and who spoke on condition of anonymity because they were not authorized to speak to the press.

The Facebook source said the investigation so far indicates between 200 million and 600 million Facebook users may have had their account passwords stored in plain text and searchable by more than 20,000 Facebook employees. The source said Facebook is still trying to determine how many passwords were exposed and for how long, but so far the inquiry has uncovered archives with plain text user passwords in them dating back to 2012.

My Facebook insider said access logs showed some 2,000 engineers or developers made approximately nine million internal queries for data elements that contained plain text user passwords.

“The longer we go into this analysis the more comfortable the legal people [at Facebook] are going with the lower bounds” of affected users, the source said. “Right now they’re working on an effort to reduce that number even more by only counting things we have currently in our data warehouse.”

In an interview with KrebsOnSecurity, Facebook software engineer Scott Renfro said the company wasn’t ready to talk about specific numbers — such as the number of Facebook employees who could have accessed the data.

Renfro said the company planned to alert affected Facebook users, but that no password resets would be required.

“We’ve not found any cases so far in our investigations where someone was looking intentionally for passwords, nor have we found signs of misuse of this data,” Renfro said. “In this situation what we’ve found is these passwords were inadvertently logged but that there was no actual risk that’s come from this. We want to make sure we’re reserving those steps and only force a password change in cases where there’s definitely been signs of abuse.”

A written statement from Facebook provided to KrebsOnSecurity says the company expects to notify “hundreds of millions of Facebook Lite users, tens of millions of other Facebook users, and tens of thousands of Instagram users.” Facebook Lite is a version of Facebook designed for low speed connections and low-spec phones.

Both Github and Twitter were forced to admit similar stumbles in recent months, but in both of those cases the plain text user passwords were available to a relatively small number of people within those organizations, and for far shorter periods of time.

Renfro said the issue first came to light in January 2019 when security engineers reviewing some new code noticed passwords were being inadvertently logged in plain text.

“This prompted the team to set up a small task force to make sure we did a broad-based review of anywhere this might be happening,” Renfro said. “We have a bunch of controls in place to try to mitigate these problems, and we’re in the process of investigating long-term infrastructure changes to prevent this going forward. We’re now reviewing any logs we have to see if there has been abuse or other access to that data.”

Facebook’s password woes come amid a tough month for the social network. Last week, The New York Times reported that federal prosecutors are conducting a criminal investigation into data deals Facebook struck with some of the world’s largest tech companies.

Earlier in March, Facebook came under fire from security and privacy experts for using phone numbers provided for security reasons — like two-factor authentication — for other things (like marketing, advertising and making users searchable by their phone numbers across the social network’s different platforms).

Update, 11:43 a.m.: Facebook has posted a statement about this incident here.

Phone numbers stink for security and authentication. They stink because most of us have so much invested in these digits that they’ve become de facto identities. At the same time, when you lose control over a phone number — maybe it’s hijacked by fraudsters, you got separated or divorced, or you were way late on your phone bill payments — whoever inherits that number can then be you in a lot of places online.

How exactly did we get to the point where a single, semi-public and occasionally transient data point like a phone number can unlock access to such a large part of our online experience? KrebsOnSecurity spoke about this at length with Allison Nixon, director of security research at New York City-based cyber intelligence firm Flashpoint.

Nixon said much of her perspective on mobile identity is colored by the lens of her work, which has her identifying some of the biggest criminals involved in hijacking phone numbers via SIM swapping attacks. Illegal SIM swaps allow fraudsters to hijack a target’s phone’s number and use it to steal financial data, passwords, cryptocurrencies and other items of value from victims.

Nixon said countless companies have essentially built their customer authentication around the phone number, and that a great many sites still let users reset their passwords with nothing more than a one-time code texted to a phone number on the account. In this attack, the fraudster doesn’t need to know the victim’s password to hijack the account: He just needs to have access to the target’s mobile phone number.

“As a consumer, I’m forced to use my phone number as an identity document, because sometimes that’s the only way to do business with a site online,” Nixon said. “But from that site’s side, when they see a password reset come in via that phone number, they have no way to know if that’s me. And there’s nothing anyone can do to stop it except to stop using phone numbers as identity documents.”

Beyond SIM-swapping attacks, there are a number of ways that phone numbers can get transferred to new owners, Nixon said. The biggest reason is lack of payment for past phone bills. But maybe someone goes through a nasty divorce or separation, and can no longer access their phone or phone accounts. The account is sent to collections and closed, and the phone number gets released back into the general pool for reassignment after a period of time.

Many major providers still let people reset their passwords with just a text message. Last week I went to regain access to a Yahoo account I hadn’t used in almost five years. Yahoo’s forgot password feature let me enter a phone number, and after entering a code sent to my phone I was able to read my email.

So, if that Yahoo account is tied to a mobile number that you can receive text messages at, then you can assume control over the account. And every other account associated with that Yahoo account. Even if that phone number no longer belongs to the person who originally established the email account.

This is exactly what happened recently to a reader who shared this account:

A while ago I bought a new phone number. I went on Yahoo! mail and typed in the phone number in the login. It asked me if I wanted to receive an SMS to gain access. I said yes, and it sent me a verification key or access code via SMS. I typed the code I received. I was surprised that I didn’t access my own email, but the email I accessed was actually the email of the previous owner of my new number.

Yahoo! didn’t even ask me to type the email address, or the first and last name. It simply sent me the SMS, I typed the code I received, and without asking me to type an email or first and last name, it gave me access to the email of my number’s PREVIOUS OWNER. Didn’t ask for credentials or email address. This seriously needs to be revised. At minimum Yahoo! should ask me to type the email address or the first and last name before sending me an SMS which contains an access code.

Brian Krebs (BK): You have your own experiences like this. Or sort of. You tell.

Allison Nixon (AN): Any threat intelligence company will have some kind of business function that requires purchasing burner phones fairly frequently, which involves getting new phone numbers. When you get new numbers, they are recycled from previous owners because there probably aren’t any new ones anymore. I get a lot of various text messages for password resets. One I kept getting was texts from this guy’s bank. Every time he got a deposit, I would get a text saying how much was deposited and some basic information about the account.

I approached the bank because I was concerned that maybe this random person would be endangered by the security research we were going to be doing with this new number. I asked them to take him off the number, but they said there wasn’t anything they could do about it.

One time I accidentally hijacked a random person’s account. I was trying to get my own account back at an online service provider, and I put a burner phone number into the site, went through the SMS password reset process, got the link and it said ‘Welcome Back’ to some username I didn’t know. Then I clicked okay and was suddenly reading the private messages of the account.

I realized I’d hijacked the account of the previous owner of the phone. It was unintentional, but also very clear that there was no technical reason I couldn’t hijack even more accounts associated with this number. This is a problem affecting a ton of service providers. This could have happened at many, many other web sites.

BK: We weren’t always so tied to our phone numbers, right? What happened?

AN: The whole concept of a phone number goes back over a hundred years. The operator would punch in a number you know was associated with your friend and you could call that person and talk to them. Back then, a phone wasn’t tied any one person’s identity, and possession of that phone number never proved that person’s identity.

But these days, phone number are tied to peoples’ identities, even though we’re recycling them and this recycling is a fundamental part of how the phone system works. Despite the fact that phone number recycling has always existed, we still have all these Internet companies who’ve decided they’re going to accept the phone number as an identity document and that’s terrible.

BK: How does the phone number compare to more traditional, physical identity documents?

AN: Take the traditional concept of identity documents — where you have to physically show up and present ID at some type of business or office, and then from there they would look up your account and you can conduct a transaction. Online, it’s totally different and you can’t physically show your ID and can’t show your face.

In the Internet ecosystem, there are different companies and services that sell things online who have settled on various factors that are considered a good enough proxy for an identity document. You supply a username, password, and sometimes you provide your email address or phone number. Often times when you set up your account you have some kind of agreed-upon way of proofing that over time. Based on that pre-established protocol, the user can log in and do transactions.

It’s not a good system and the way the whole thing works just enables fraud. When you’re bottlenecked into physically showing up in a place, there’s only so much fraud you can do. A lot of attacks against phone companies are not attacking the inherent value of a phone number, but its use as an identity document.

BK: You said phone number recycling is a fundamental part of how the phone system works. Talk more about that, how common that is.

AN: You could be divorced, or thrown into sudden poverty after losing a job. But that number can be given away, and if it goes to someone else you don’t get it back. There all kinds of life situations where a phone number is not a good identifier.

Maybe part of the reason the whole phone number recycling issue doesn’t get much attention is people who can’t pay their bills probably don’t have a lot of money to steal anyways, but it’s pretty terrible that this situation can be abused to kick people when they’re down. I don’t think a lot of money can be stolen in this way, but I do think the fact that this happens really can undermine the entire system.

BK: It seems to me that it would be a good thing if more online merchants made it easier to log in to their sites without using passwords, but instead with an app that just asks hey was that you just now trying to log in? Yes? Okay. Boom, you’re logged in. Seems like this kind of “push” login can leverage the user’s smart phone while not relying on the number — or passwords, for that matter.

If phone numbers are bad, what should we look to as more reliable and resilient identifiers?

AN: That’s something I’ve been thinking a lot about lately. It seems like all of the other options are either bad or really controversial. On the one hand, I want my bank to know who I am, and I want to expose my email and phone number to them so they can verify it’s me and know how to get in touch with me if needed. But if I’m setting up an email account, I don’t want to have to give them all of my information. I’m not attached to any one alternative idea, I just don’t like what we’re doing now.

For more on what you can do to reduce your dependence on mobile phone numbers, check out the “What Can You Do?” section of Hanging Up on Mobile in the Name of Security.

Online advertising firm Sizmek Inc. [NASDAQ: SZMK] says it is investigating a security incident in which a hacker was reselling access to a user account with the ability to modify ads and analytics for a number of big-name advertisers.

In a recent posting to a Russian-language cybercrime forum, an individual who’s been known to sell access to hacked online accounts kicked off an auction for “the admin panel of a big American ad platform.”

“You can add new users to the ad system, edit existing ones and ad offers,” the seller wrote. The starting bid was $800.

The seller included several screen shots of the ad company’s user panel. A few minutes on LinkedIn showed that many of these people are current or former employees of Sizmek.

The seller also shared a screenshot of the ad network’s Alexa site rankings:

I checked Sizmek’s Alexa page and at the time it almost mirrored the statistics shown in the screenshot above. Sizmek’s own marketing boilerplate says the company operates its ad platform in more than 70 countries, connecting more than 20,000 advertisers and 3,600 agencies to audiences around the world. The company is listed by market analysis firm Datanyze.com as the world third-largest ad server network.

After reaching out to a number of folks at Sizmek, I heard back from George Pappachen, the company’s general counsel.

Pappachen said the account being resold on the dark web is a regular user account (not a all-powerful administrator account, despite the seller’s claim) for its Sizmek Advertising Suite (SAS). Pappachen described Sizmek’s SAS product line as “a sizable and important one” for the company and a relatively new platform that has hundreds of users.

He acknowledged that the purloined account had the ability to add or modify the advertising creatives that get run on customer ad campaigns. And Sizmek is used in ad campaigns for some of the biggest brands out there. Some of the companies shown in the screenshot of the panel shared by the dark web seller include PR firm Fleishman-Hillard, media giants Fox Broadcasting, Gannett, and Hearst Digital, as well as Kohler, and Pandora.

Crooks who exploited this access could hijack existing ad campaigns running on some of the world’s top online properties, by inserting malicious scripts into the HTML code of ads that run on popular sites. Or they could hijack referral commissions destined for others and otherwise siphon ad profits from the system.

“Or someone who is looking to sabotage our systems in a bigger way or allow malicious code to enter our systems,” Pappachen offered.

Pappachen said Sizmek forced a password reset on all internal employees (“a few hundred”), and that the company is scrubbing its SAS user database for departed employees, partners and vendors whose accounts may have been hijacked.

“We’re now doing some level of screening to see if there’s been any kind of intrusion we can detect,” Pappachen said. “It seemed like [the screenshots were accounts from] past employees. I think there were even a couple of vendors that had access to the system previously.”

The Sizmek incident carries a few lessons. For starters, it seems like an awful lot of people at Sizmek had access to sensitive controls and data a good deal longer than they should have. User inventory and management is a sometimes painful but very necessary ongoing security process at any mature organization.

Best practices in this space call for actively monitoring all accounts — users and admins — for signs of misuse or unauthorized access. And when employees or vendors sever business ties, terminate their access immediately.

Pappachen asked KrebsOnSecurity what else could have prevented this. I suggested some form of mobile-based multi-factor authentication option would prevent stolen credentials from turning into instant access. He said the company does use app/mobile based authentication for several of its new products and some internal programs, but allowed that “the legacy ones probably did not have this feature.”

PASSWORD SPRAYING

It’s not clear how this miscreant got access to Sizmek’s systems. But it is clear that attackers have moved rapidly of late toward targeting employees at key roles in companies they’d like to infiltrate, and they’re automating the guessing of passwords for employee accounts. One popular version of this attack involves what’s known as “password spraying,” which attempts to access a large number of accounts (usernames/email addresses) with a few commonly used passwords.

There are technologies like CAPTCHAs — requiring the user to solve an image challenge or retype squiggly letters — which try to weed out automated bot programs from humans. Then again, password spraying attacks often are conducted “low and slow” to help evade these types of bot challenges.

Password spraying was suspected in a compromise reported last week at Citrix, which said it heard from the FBI on March 6 that attackers had successfully compromised multiple Citrix employee accounts. A little-known security company Resecurity claimed it had evidence that Iranian hackers were responsible, had been in Citrix’s network for years, and had offloaded terabytes of data.

Resecurity drew criticism from many in the security community for not sharing enough evidence of the attacks. But earlier this week the company updated its blog post to include several Internet addresses and proxies it says the attackers used in the Citrix campaign. The update stated the attackers had gained access to nearly 32,000 Citrix accounts through password spraying.

Resecurity also presented evidence that it notified Citrix of the breach as early as Dec. 28, 2018. Citrix initially denied that claim, but has since acknowledged that it did receive a notification from Resecurity on Dec. 28. Citrix has declined to comment further beyond saying it is still investigating the matter.

BRUTE-FORCE LIGHT

If anything, password spraying is a fairly crude, if sometimes marginally effective attack tool. But what we’ve started to see more of over the past year has been what one might call “brute-force light” attacks on accounts. A source who has visibility into a botnet of Internet of Things devices that is being mostly used for credential stuffing attacks said he’s seeing the attackers use distributed, hacked systems like routers, security cameras and digital video recorders to anonymize their repeated queries.

This source noticed that the automated system used by the IoT botmasters typically will try several dozen variations on a password that each target had previously used at another site — adding a “1” or an exclamation point at the end of a password, or capitalizing the first letter of whole words in previous passwords, and so on.

The idea behind this method to snare not only users who are wholesale re-using the same password across multiple sites, but to also catch users who may just be re-using slight variations on the same password.

This form of credential stuffing is brilliant from the attacker’s perspective because it probably nets him quite a few more correct guesses than normal password spraying techniques.

It’s also smart because it borrows from human nature. Let’s say your average password re-user is in the habit of recycling the password “monkeybutt.” But then he gets to a site that wants him to use capitalization in his password to create an account. So what does this user pick? Yes, “Monkeybutt.” Or “Monkeybutt1”. You get the picture.

There’s an old saying in security: “Everyone gets penetration tested, whether or not they pay someone for the pleasure.” It’s kind of like that with companies and their users and passwords. How would your organization hold up to a password spraying or brute-force light attack? If you don’t know, you should probably find out, and then act on the results accordingly. I guarantee you the bad guys are going to find out even if you don’t.