Posts Tagged: Facebook


20
Apr 18

Is Facebook’s Anti-Abuse System Broken?

Facebook has built some of the most advanced algorithms for tracking users, but when it comes to acting on user abuse reports about Facebook groups and content that clearly violate the company’s “community standards,” the social media giant’s technology appears to be woefully inadequate.

Last week, Facebook deleted almost 120 groups totaling more than 300,000 members. The groups were mostly closed — requiring approval from group administrators before outsiders could view the day-to-day postings of group members.

However, the titles, images and postings available on each group’s front page left little doubt about their true purpose: Selling everything from stolen credit cards, identities and hacked accounts to services that help automate things like spamming, phishing and denial-of-service attacks for hire.

To its credit, Facebook deleted the groups within just a few hours of KrebsOnSecurity sharing via email a spreadsheet detailing each group, which concluded that the average length of time the groups had been active on Facebook was two years. But I suspect that the company took this extraordinary step mainly because I informed them that I intended to write about the proliferation of cybercrime-based groups on Facebook.

That story, Deleted Facebook Cybercrime Groups had 300,000 Members, ended with a statement from Facebook promising to crack down on such activity and instructing users on how to report groups that violate it its community standards.

In short order, some of the groups I reported that were removed re-established themselves within hours of Facebook’s action. I decided instead of contacting Facebook’s public relations arm directly that I would report those resurrected groups and others using Facebook’s stated process. Roughly two days later I received a series replies saying that Facebook had reviewed my reports but that none of the groups were found to have violated its standards. Here’s a snippet from those replies:

Perhaps I should give Facebook the benefit of the doubt: Maybe my multiple reports one after the other triggered some kind of anti-abuse feature that is designed to throttle those who would seek to abuse it to get otherwise legitimate groups taken offline — much in the way that pools of automated bot accounts have been known to abuse Twitter’s reporting system to successfully sideline accounts of specific targets.

Or it could be that I simply didn’t click the proper sequence of buttons when reporting these groups. The closest match I could find in Facebook’s abuse reporting system were, “Doesn’t belong on Facebook,” and “Purchase or sale of drugs, guns or regulated products.” There was/is no option for “selling hacked accounts, credit cards and identities,” or anything of that sort.

In any case, one thing seems clear: Naming and shaming these shady Facebook groups via Twitter seems to work better right now for getting them removed from Facebook than using Facebook’s own formal abuse reporting process. So that’s what I did on Thursday. Here’s an example: Continue reading →


16
Apr 18

Deleted Facebook Cybercrime Groups Had 300,000 Members

Hours after being alerted by KrebsOnSecurity, Facebook last week deleted almost 120 private discussion groups totaling more than 300,000 members who flagrantly promoted a host of illicit activities on the social media network’s platform. The scam groups facilitated a broad spectrum of shady activities, including spamming, wire fraud, account takeovers, phony tax refunds, 419 scams, denial-of-service attack-for-hire services and botnet creation tools. The average age of these groups on Facebook’s platform was two years.

On Thursday, April 12, KrebsOnSecurity spent roughly two hours combing Facebook for groups whose sole purpose appeared to be flouting the company’s terms of service agreement about what types of content it will or will not tolerate on its platform.

One of nearly 120 different closed cybercrime groups operating on Facebook that were deleted late last week. In total, there were more than 300,000 members of these groups. The average age of these groups was two years, but some had existed for up to nine years on Facebook

My research centered on groups whose singular focus was promoting all manner of cyber fraud, but most especially those engaged in identity theft, spamming, account takeovers and credit card fraud. Virtually all of these groups advertised their intent by stating well-known terms of fraud in their group names, such as “botnet helpdesk,” “spamming,” “carding” (referring to credit card fraud), “DDoS” (distributed denial-of-service attacks), “tax refund fraud,” and account takeovers.

Each of these closed groups solicited new members to engage in a variety of shady activities. Some had existed on Facebook for up to nine years; approximately ten percent of them had plied their trade on the social network for more than four years.

Here is a spreadsheet (PDF) listing all of the offending groups reported, including: Their stated group names; the length of time they were present on Facebook; the number of members; whether the group was promoting a third-party site on the dark or clear Web; and a link to the offending group. A copy of the same spreadsheet in .csv format is available here.

The biggest collection of groups banned last week were those promoting the sale and use of stolen credit and debit card accounts. The next largest collection of groups included those facilitating account takeovers — methods for mass-hacking emails and passwords for countless online accounts such Amazon, Google, Netflix, PayPal, as well as a host of online banking services.

This rather active Facebook group, which specialized in identity theft and selling stolen bank account logins, was active for roughly three years and had approximately 2,500 members.

In a statement to KrebsOnSecurity, Facebook pledged to be more proactive about policing its network for these types of groups.

“We thank Mr. Krebs for bringing these groups to our attention, we removed them as soon as we investigated,” said Pete Voss, Facebook’s communications director. “We investigated these groups as soon as we were aware of the report, and once we confirmed that they violated our Community Standards, we disabled them and removed the group admins. We encourage our community to report anything they see that they don’t think should be in Facebook, so we can take swift action.” Continue reading →


9
Apr 18

Don’t Give Away Historic Details About Yourself

Social media sites are littered with seemingly innocuous little quizzes, games and surveys urging people to reminisce about specific topics, such as “What was your first job,” or “What was your first car?” The problem with participating in these informal surveys is that in doing so you may be inadvertently giving away the answers to “secret questions” that can be used to unlock access to a host of your online identities and accounts.

I’m willing to bet that a good percentage of regular readers here would never respond — honestly or otherwise — to such questionnaires (except perhaps to chide others for responding). But I thought it was worth mentioning because certain social networks — particularly Facebook — seem positively overrun with these data-harvesting schemes. What’s more, I’m constantly asking friends and family members to stop participating in these quizzes and to stop urging their contacts to do the same.

On the surface, these simple questions may be little more than an attempt at online engagement by otherwise well-meaning companies and individuals. Nevertheless, your answers to these questions may live in perpetuity online, giving identity thieves and scammers ample ammunition to start gaining backdoor access to your various online accounts.

Consider, for example, the following quiz posted to Facebook by San Benito Tire Pros, a tire and auto repair shop in California. It asks Facebook users, “What car did you learn to drive stick shift on?”

I hope this is painfully obvious, but for many people the answer will be the same as to the question, “What was the make and model of your first car?”, which is one of several “secret questions” most commonly used by banks and other companies to let customers reset their passwords or gain access to the account without knowing the password.

This simple one-question quiz has been shared more than 250 times on Facebook since it was posted a week ago. Thousands of Facebook users responded in earnest, and in so doing linked their profile to the answer.

Probably the most well-known and common secret question, “what was the name of your first pet,” comes up in a number of Facebook quizzes that, incredibly, thousands of people answer willingly and (apparently) truthfully. When I saw this one I was reminded of this hilarious 2007 Daily Show interview wherein Jon Stewart has Microsoft co-founder Bill Gates on and tries to slyly ask him the name of his first pet.

Almost 5,000 Facebook users answered this common password reset secret question.

Continue reading →


13
Nov 17

How to Opt Out of Equifax Revealing Your Salary History

A KrebsOnSecurity series on how easy big-three credit bureau Equifax makes it to get detailed salary history data on tens of millions of Americans apparently inspired a deeper dive on the subject by Fast Company, which examined how this Equifax division has been one of the company’s best investments. In this post, I’ll show you how to opt out of yet another Equifax service that makes money at the expense of your privacy.

My original report showed how the salary history for tens of millions of employees at some of the world’s largest corporations was available to anyone armed with an employee’s Social Security number and date of birth — information that was stolen on 145.5 million Americans in the recent breach at Equifax.

Equifax took down their salary portal — a service from the company’s Workforce Solutions division known as The Work Number (formerly “TALX“) — just a few hours after my story went live on Oct. 8. The company explained that the site was being disabled for routine maintenance, but Equifax didn’t fully reopen the portal until Nov. 2, following the addition of unspecified “security improvements.”

Fast Company writer Joel Winston’s story examines how some 70,000 companies — including Amazon, AT&T, Facebook, Microsoft, Oracle, Twitter and Wal-Mart — actually pay Equifax to collect, organize, and re-sell their employees’ personal income information and work history.

“A typical employee at Facebook (which also owns Instagram and WhatsApp) may require verification of his employment through TALX when he leases an apartment, updates his immigration status, applies for a loan or public aid, or applies for a new job,” Winston writes. “If his new prospective employer is among the 70,000 approved entities in Equifax’s verifier network with a “permissible purpose,” that company can purchase his employment and income information for about $20.”

While this may sound like a nice and legitimate use of salary data, the point of my original report was that this salary data is also available to anyone who has the Social Security number and date of birth on virtually any person who once worked at a company that uses this Equifax service.

In May 2017, KrebsOnSecurity broke the story of how this same Equifax Workforce portal was abused for an entire year by identity thieves involved in tax refund fraud with the Internal Revenue Service. Fraudsters used SSN and DOB data to reset the 4-digit PINs given to customer employees as a password, and then steal W-2 tax data after successfully answering personal questions about those employees.

Curiously, Equifax claims they have no evidence that anyone was harmed as a result of the year-long pattern of tax fraud related to how easy it was to coax salary and payroll data out of its systems.

“We do not know of any specific fraud incidents linked with the Work Number,” Equifax spokeswoman Marisa Salcines told Fast Company.

This statement sounds suspiciously like what big-three credit bureau Experian told lawmakers in 2014 after they were hauled up to Capitol Hill to explain another breach that was scooped by KrebsOnSecurity: That a Vietnamese man who ran an identity theft service which catered to tax refund fraudsters had access for nine months to more than 200 million consumer records maintained by Experian.

Experian’s suits told lawmakers that no consumers were harmed even as the U.S. Secret Service was busy arresting customers of this identity theft service — nearly all of whom were involved in tax refund fraud and other forms of consumer ID theft. Continue reading →


2
Aug 17

Flash Player is Dead, Long Live Flash Player!

Adobe last week detailed plans to retire its Flash Player software, a cross-platform browser plugin so powerful and so packed with security holes that it has become the favorite target of malware developers. To help eradicate this ubiquitous liability, Adobe is enlisting the help of Apple, Facebook, Google, Microsoft and Mozilla. But don’t break out the bubbly just yet: Adobe says Flash won’t be put down officially until 2020.

brokenflash-aIn a blog post about the move, Adobe said more sites are turning away from proprietary code like Flash toward open standards like HTML5, WebGL and WebAssembly, and that these components now provide many of the capabilities and functionalities that plugins pioneered.

“Over time, we’ve seen helper apps evolve to become plugins, and more recently, have seen many of these plugin capabilities get incorporated into open web standards,” Adobe said. “Today, most browser vendors are integrating capabilities once provided by plugins directly into browsers and deprecating plugins.”

It’s remarkable how quickly Flash has seen a decline in both use and favor, particularly among the top browser makers. Just three years ago, at least 80 percent of desktop Chrome users visited a site with Flash each day, according to Google. Today, usage of Flash among Chrome users stands at just 17 percent and continues to decline (see Google graphic below).

For Mac users, the turning away from Flash began in 2010, when Apple co-founder Steve Jobs famously penned his “Thoughts on Flash” memo that outlined the reasons why the technology would not be allowed on the company’s iOS products. Apple stopped pre-installing the plugin that same year.

The percentage of Chrome users over time that have used Flash on a Web site. Image: Google.

The percentage of Chrome users over time that have used Flash on a Web site. Image: Google.

“Today, if users install Flash, it remains off by default,” a post by Apple’s WebKit Team explains. “Safari requires explicit approval on each website before running the Flash plugin.”

Mozilla said that starting this month Firefox users will choose which websites are able to run the Flash plugin.

“Flash will be disabled by default for most users in 2019, and only users running the Firefox Extended Support Release will be able to continue using Flash through the final end-of-life at the end of 2020,” writes Benjamin Smedberg for Mozilla. “In order to preserve user security, once Flash is no longer supported by Adobe security patches, no version of Firefox will load the plugin.” Continue reading →


16
Aug 16

SSA: Ixnay on txt msg reqmnt 4 e-acct, sry

The U.S. Social Security Administration says it is reversing a newly enacted policy that required a cell phone number from all Americans who wished to manage their retirement benefits at ssa.gov. The move comes after a policy rollout marred by technical difficulties and criticism that the new requirement did little to prevent identity thieves from siphoning benefits from Americans who hadn’t yet created accounts at ssa.gov for themselves.

In an announcement last month, the SSA said all new and existing ‘my Social Security’ account holders would need to provide a cell phone number. The SSA said the numbers would be used to send recipients an 8-digit code via text message that needs to be entered along with a username and password to log in to the site.

But sometime in the past few days, apparently, the SSA decided to rescind the cell phone rule.

“We removed the requirement to use a cell phone to access your account,” the agency noted in a message posted to its mySocial Security portal. “While it’s not mandatory, we encourage those of you who have a text capable cell phone to take advantage of this optional extra security. We continue to pursue more options beyond cell phone texting.”

Hopefully, those options will include using the U.S. Mail to send Americans a one-time code that needs to be entered at the SSA’s Web site to complete the sign-up process. I should note that the SSA is already mailing out paper letters via snail mail to Americans who’ve signed up for an SSA account online; they’re just not using that mailing to securely complete the signup and authentication process.

Here’s a redacted letter that a friend of mine received and shared the other day after signing up for an account online. It merely explains what the agency already explained about the texting policy via its Web site.

A letter that the Social Security Administration sends out via the U.S. Mail for every American who signs up to manage their benefits at ssa.gov.

A letter that the Social Security Administration sends out via the U.S. Mail for every American who signs up to manage their benefits at ssa.gov.

The SSA does still offer the text message feature as part of what it calls “extra security” options. These extra options by the way do include the sending users a special code via the U.S. Mail that has to be entered on the agency’s site to complete the signup process. If you choose to enable extra security, the SSA will then ask you for:

  • The last eight digits of your Visa, MasterCard, or Discover credit card;
  • Information from your W2 tax form;
  • Information from a 1040 Schedule SE (self-employment) tax form; or
  • Your direct deposit amount, if you receive Social Security benefits.

Sadly, crooks won’t go through the more rigorous signup process — they’ll choose the option that requires less information. That means it is still relatively easy for thieves to create an account in the name of Americans who have not already created one for themselves. All one would need is the target’s name, date of birth, Social Security number, residential address, and phone number. This personal data can be bought for roughly $3-$4 from a variety of cybercrime shops online. Continue reading →


6
Jun 16

Password Re-user? Get Ready to Get Busy

In the wake of megabreaches at some of the Internet’s most-recognized destinations, don’t be surprised if you receive password reset requests from numerous companies that didn’t experience a breach: Some big name companies — including Facebook and Netflix — are in the habit of combing through huge data leak troves for credentials that match those of their customers and then forcing a password reset for those users.

Netflix sent out notices to customers who re-used their Netflix password at other sites that were hacked.

Netflix sent out notices to customers who re-used their Netflix password at other sites that were hacked. This notice was shared by a reader who had re-used his Netflix password at one of the breached companies.

Netflix.com, for example, sent out a notification late last week to users who made the mistake of re-using their Netflix password at Linkedin, Tumblr or MySpace. All of three of those breaches are years old, but the scope of the intrusions (more than a half billion usernames and passwords leaked in total) only became apparent recently when the credentials were posted online at various sites and services.

“We believe your Netflix account credentials may have been included in a recent release of email addresses and passwords from an older breach at another company,” the message from Neflix reads. “Just to be safe, we’ve reset your password as a precautionary measure.”

The missive goes on to urge recipients to visit Netflix.com and click the “forgot your email or password” link to reset their passwords.

Netflix is taking this step because it knows from experience that cybercriminals will be using the credentials leaked from Tumblr, MySpace and LinkedIn to see if they work on a variety of third-party sites (including Netflix).

As I wrote last year in the aftermath of the AshleyMadison breach that exposed tens of millions of user credentials, Netflix’s forensics team has been using a tool that the company released in 2014 called Scumblr, which scours high-profile sites for specific terms and data.

“Some Netflix members have received emails encouraging them to change their account passwords as a precautionary measure due to the recent disclosure of additional credentials from an older breach at another internet company,” Netflix said in a statement released to KrebsOnSecurity. “Note that we are always engaged in these types of proactive security measures (leveraging Scumblr in addition to other mechanisms and data sources), not just in the case of major security breaches such as this one.”

Continue reading →


28
Apr 15

China Censors Facebook.net, Blocks Sites With “Like” Buttons

Chinese government censors at the helm of the “Great Firewall of China” appear to have inadvertently blocked Chinese Web surfers from visiting pages that call out to connect.facebook.net, a resource used by Facebook’s “like” buttons. While the apparent screw-up was quickly fixed, the block was cached by many Chinese networks — effectively blocking millions of Chinese Web surfers from visiting a huge number of sites that are not normally censored.

fblikeunlike

Sometime in the last 24 hours, Web requests from within China for a large number of websites were being redirected to wpkg.org, an apparently innocuous site hosting an open-source, automated software deployment, upgrade and removal program for Windows.

One KrebsOnSecurity reader living in China who was inconvenienced by the glitch said he discovered the problem just by trying to access the regularly non-blocked UK newspapers online. He soon noticed a large swath of other sites were also being re-directed to the same page.

“It has the feel of a cyber attack rather than a new addition to the Great Firewall,” said the reader, who asked not to be identified by name. “I thought it might be malware on my laptop, but then I got an email from the IT services at my university saying the issue was nation-wide, which made me curious. It’s obviously very normal for sites to be blocked here in China, but the scale and the type of sites being blocked (and the fact that we’re being re-directed instead of the usual 404 result) suggests a problem with the Internet system itself. It doesn’t seem like the kind of thing the Chinese gov would do intentionally, which raises some interesting questions.”

Nicholas Weaver, a researcher who has delved deeply into Chinese censorship tools in his role at the International Computer Science Institute (ICSI) and the University of California, Berkeley, agrees that the blocking of connect.facebook.net by censors inside the country was likely a mistake.

“Any page that had a Facebook Connect element on it that was unencrypted and visited from within China would instead get this thing which would reload the main page of wpkg.org,” Weaver said, noting that while Facebook.com always encrypts users’ connections, sites that rely on Facebook “like” buttons and related resources draw those from connect.facebook.net. “That screw-up seems to have been fairly quickly corrected, but the effect of it has lingered because it got into peoples’ domain name system (DNS) caches.”

In short, a brief misstep in censorship can have lasting and far flung repercussions. But why should this be considered a screw-up by Chinese censors? For one thing, it was corrected quickly, Weaver said.

“Also, the Chinese censors don’t benefit from it, because this caused a huge amount of disruption to Chinese web surfers on pages that the government doesn’t want to censor,” he said. Continue reading →


2
Apr 14

Android Botnet Targets Middle East Banks

I recently encountered a botnet targeting Android smartphone users who bank at financial institutions in the Middle East. The crude yet remarkably effective mobile bot that powers this whole operation comes disguised as one of several online banking apps, has infected more than 2,700 phones, and has intercepted at least 28,000 text messages.

The botnet — which I’ve affectionately dubbed “Sandroid” — comes bundled with Android apps made to look like mobile two-factor authentication modules for various banks, including Riyad Bank, SAAB (formerly the Saudi British Bank), AlAhliOnline (National Commercial Bank), Al Rajhi Bank, and Arab National Bank.

The fake Android bank apps employed by this botnet.

The fake Android bank apps employed by the Sandroid botnet.

It’s not clear how the apps are initially presented to victims, but if previous such scams are any indication they are likely offered after infecting the victim’s computer with a password-stealing banking Trojan. Many banks send customers text messages containing one-time codes that are used to supplement a username and password when the customer logs on to the bank’s Web site. And that precaution of course requires attackers interested in compromising those accounts to also hack the would-be victim’s phone.

Banking Trojans — particularly those targeting customers of financial institutions outside of the United States — will often throw up a browser pop-up box that mimics the bank and asks the user to download a “security application” on their mobile phones. Those apps are instead phony programs that merely intercept and then relay the victim’s incoming SMS messages to the botnet master, who can then use the code along with the victim’s banking username and password to log in as the victim.

Text messages intercepted by the Sandroid botnet malware.

Some of the 28,000+ text messages intercepted by the Sandroid botnet malware.

Continue reading →


5
Dec 13

How Many Zero-Days Hit You Today?

On any given day, nation-states and criminal hackers have access to an entire arsenal of zero-day vulnerabilities  — undocumented and unpatched software flaws that can be used to silently slip past most organizations’ digital defenses, new research suggests.  That sobering conclusion comes amid mounting evidence that thieves and cyberspies are ramping up spending to acquire and stockpile these digital armaments.

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Security experts have long suspected that governments and cybercriminals alike are stockpiling zero-day bugs: After all, the thinking goes, if the goal is to exploit these weaknesses in future offensive online attacks, you’d better have more than a few tricks up your sleeve because it’s never clear whether or when those bugs will be independently discovered by researchers or fixed by the vendor. Those suspicions were confirmed very publicly in 2010 with the discovery of Stuxnet, a weapon apparently designed to delay Iran’s nuclear ambitions and one that relied upon at least four zero-day vulnerabilities.

Documents recently leaked by National Security Agency whistleblower Edward Snowden indicate that the NSA spent more than $25 million this year alone to acquire software vulnerabilities from vendors. But just how many software exploits does that buy, and what does that say about the number of zero-day flaws in private circulation on any given day?

These are some of the questions posed by Stefan Frei, research director for Austin, Texas-based NSS Labs. Frei pored over reports from and about some of those private vendors — including boutique exploit providers like Endgame Systems, Exodus Intelligence, Netragard, ReVuln and VUPEN — and concluded that jointly these firms alone have the capacity to sell more than 100 zero-day exploits per year.

According to Frei, if we accept that the average zero-day exploit persists for about 312 days before it is detected (an estimate made by researchers at Symantec Research Labs), this means that these firms probably provide access to at least 85 zero-day exploits on any given day of the year. These companies all say they reserve the right to restrict which organizations, individuals and nation states may purchase their products, but they all expressly do not share information about exploits and flaws with the affected software vendors.

Frei's minimum estimate of exploits offered by boutique exploit providers each year.

Frei’s minimum estimate of exploits offered by boutique exploit providers each year.

KNOWN UNKNOWNS

That approach stands apart from the likes of HP TippingPoint‘s Zero-Day Initiative (ZDI) and Verisign‘s iDefense Vulnerability Contributor Program (VCP), which pay researchers in exchange for the rights to their vulnerability research. Both ZDI and iDefense also manage the communication with the affected vendors, ship stopgap protection for the vulnerabilities to their customers, and otherwise keep mum on the flaws until the vendor ships an update to fix the bugs.

Frei also took stock of the software vulnerabilities collected by these two companies, and found that between 2010 and 2012, the ZDI and VCP programs together published 1,026 flaws, of which 425 (44 percent) targeted flaws in Microsoft, Apple, Oracle, Sun and Adobe products. The average time from purchase to publication was 187 days.

“On any given day during these three years, the VCP and ZDI programs possessed 58 unpublished vulnerabilities affecting five vendors, or 152 vulnerabilities total,” Frei wrote in a research paper released today.

vcp-zdi

Frei notes that the VCP and ZDI programs use the information they purchase only for the purpose of building better protection for their customers, and since they share the information with the software vendors in order to develop and release patches, the overall risk is comparatively low. Also, the vulnerabilities collected and reported by VCP and ZDI are not technically zero-days, since one important quality of a zero-day is that it is used in-the-wild to attack targets before the responsible vendor can ship a patch to fix the problem.

In any case, Frei says his analysis clearly demonstrates that critical vulnerability information is available in significant quantities for private groups, for extended periods and at a relatively low cost.

“So everybody knows there are zero days, but when we talk to C-Level executives, very often we find that these guys don’t have a clue, because they tell us, ‘Yeah, but we’ve never been compromised’,” Frei said in an interview.  “And we always ask them, ‘How do you know?'”

Continue reading →