April, 2018


25
Apr 18

DDoS-for-Hire Service Webstresser Dismantled

Authorities in the U.S., U.K. and the Netherlands on Tuesday took down popular online attack-for-hire service WebStresser.org and arrested its alleged administrators. Investigators say that prior to the takedown, the service had more than 136,000 registered users and was responsible for launching somewhere between four and six million attacks over the past three years.

The action, dubbed “Operation Power Off,” targeted WebStresser.org (previously Webstresser.co), one of the most active services for launching point-and-click distributed denial-of-service (DDoS) attacks. WebStresser was one of many so-called “booter” or “stresser” services — virtual hired muscle that anyone can rent to knock nearly any website or Internet user offline.

Webstresser.org (formerly Webstresser.co), as it appeared in 2017.

“The damage of these attacks is substantial,” reads a statement from the Dutch National Police in a Reddit thread about the takedown. “Victims are out of business for a period of time, and spend money on mitigation and on (other) security measures.”

In a separate statement released this morning, Europol — the law enforcement agency of the European Union — said “further measures were taken against the top users of this marketplace in the Netherlands, Italy, Spain, Croatia, the United Kingdom, Australia, Canada and Hong Kong.” The servers powering WebStresser were located in Germany, the Netherlands and the United States, according to Europol.

The U.K.’s National Crime Agency said WebStresser could be rented for as little as $14.99, and that the service allowed people with little or no technical knowledge to launch crippling DDoS attacks around the world.

Neither the Dutch nor U.K. authorities would say who was arrested in connection with this takedown. But according to information obtained by KrebsOnSecurity, the administrator of WebStresser allegedly was a 19-year-old from Prokuplje, Serbia named Jovan Mirkovic.

Mirkovic, who went by the hacker nickname “m1rk,” also used the alias “Mirkovik Babs” on Facebook where for years he openly discussed his role in programming and ultimately running WebStresser. The last post on Mirkovic’s Facebook page, dated April 3 (the day before the takedown), shows the young hacker sipping what appears to be liquor while bathing. Below that image are dozens of comments left in the past few hours, most of them simply, “RIP.”

Continue reading →


23
Apr 18

Transcription Service Leaked Medical Records

MEDantex, a Kansas-based company that provides medical transcription services for hospitals, clinics and private physicians, took down its customer Web portal last week after being notified by KrebsOnSecurity that it was leaking sensitive patient medical records — apparently for thousands of physicians.

On Friday, KrebsOnSecurity learned that the portion of MEDantex’s site which was supposed to be a password-protected portal physicians could use to upload audio-recorded notes about their patients was instead completely open to the Internet.

What’s more, numerous online tools intended for use by MEDantex employees were exposed to anyone with a Web browser, including pages that allowed visitors to add or delete users, and to search for patient records by physician or patient name. No authentication was required to access any of these pages.

This exposed administrative page from MEDantex’s site granted anyone complete access to physician files, as well as the ability to add and delete authorized users.

Several MEDantex portal pages left exposed to the Web suggest that the company recently was the victim of WhiteRose, a strain of ransomware that encrypts a victim’s files unless and until a ransom demand is paid — usually in the form of some virtual currency such as bitcoin.

Contacted by KrebsOnSecurity, MEDantex founder and chief executive Sreeram Pydah confirmed that the Wichita, Kansas based transcription firm recently rebuilt its online servers after suffering a ransomware infestation. Pydah said the MEDantex portal was taken down for nearly two weeks, and that it appears the glitch exposing patient records to the Web was somehow incorporated into that rebuild.

“There was some ransomware injection [into the site], and we rebuilt it,” Pydah said, just minutes before disabling the portal (which remains down as of this publication). “I don’t know how they left the documents in the open like that. We’re going to take the site down and try to figure out how this happened.”

It’s unclear exactly how many patient records were left exposed on MEDantex’s site. But one of the main exposed directories was named “/documents/userdoc,” and it included more than 2,300 physicians listed alphabetically by first initial and last name. Drilling down into each of these directories revealed a varying number of patient records — displayed and downloadable as Microsoft Word documents and/or raw audio files.

Although many of the exposed documents appear to be quite recent, some of the records dated as far back as 2007. It’s also unclear how long the data was accessible, but this Google cache of the MEDantex physician portal seems to indicate it was wide open on April 10, 2018.

Among the clients listed on MEDantex’s site include New York University Medical Center; San Francisco Multi-Specialty Medical Group; Jackson Hospital in Montgomery Ala.; Allen County Hospital in Iola, Kan; Green Clinic Surgical Hospital in Ruston, La.; Trillium Specialty Hospital in Mesa and Sun City, Ariz.; Cooper University Hospital in Camden, N.J.; Sunrise Medical Group in Miami; the Wichita Clinic in Wichita, Kan.; the Kansas Spine Center; the Kansas Orthopedic Center; and Foundation Surgical Hospitals nationwide. MEDantex’s site states these are just some of the healthcare organizations partnering with the company for transcription services. Continue reading →


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 →


18
Apr 18

A Sobering Look at Fake Online Reviews

In 2016, KrebsOnSecurity exposed a network of phony Web sites and fake online reviews that funneled those seeking help for drug and alcohol addiction toward rehab centers that were secretly affiliated with the Church of Scientology. Not long after the story ran, that network of bogus reviews disappeared from the Web. Over the past few months, however, the same prolific purveyor of these phantom sites and reviews appears to be back at it again, enlisting the help of Internet users and paying people $25-$35 for each fake listing.

Sometime in March 2018, ads began appearing on Craigslist promoting part-time “social media assistant” jobs, in which interested applicants are directed to sign up for positions at seorehabs[dot]com. This site promotes itself as “leaders in addiction recovery consulting,” explaining that assistants can earn a minimum of $25 just for creating individual Google for Business listings tied to a few dozen generic-sounding addiction recovery center names, such as “Integra Addiction Center,” and “First Exit Recovery.”

The listing on Craigslist.com advertising jobs for creating fake online businesses tied to addiction rehabilitation centers.

Applicants who sign up are given detailed instructions on how to step through Google’s anti-abuse process for creating listings, which include receiving a postcard via snail mail from Google that contains a PIN which needs to be entered at Google’s site before a listing can be created.

Assistants are cautioned not to create more than two listings per street address, but otherwise to use any U.S.-based street address and to leave blank the phone number and Web site for the new business listing.

A screen shot from Seorehabs’ instructions for those hired to create rehab center listings.

In my story Scientology Seeks Captive Converts Via Google Maps, Drug Rehab Centers, I showed how a labyrinthine network of fake online reviews that steered Internet searches toward rehab centers funded by Scientology adherents was set up by TopSeek Inc., which bills itself as a collection of “local marketing experts.” According to LinkedIn, TopSeek is owned by John Harvey, an individual (or alias) who lists his address variously as Sacramento, Calif. and Hawaii.

Although the current Web site registration records from registrar giant Godaddy obscure the information for the current owner of seorehabs[dot]com, a historic WHOIS search via DomainTools shows the site was also registered by John Harvey and TopSeek in 2015. Mr. Harvey did not respond to requests for comment. [Full disclosure: DomainTools previously was an advertiser on KrebsOnSecurity].

TopSeek’s Web site says it works with several clients, but most especially Narconon International — an organization that promotes the rather unorthodox theories of Scientology founder L. Ron Hubbard regarding substance abuse treatment and addiction.

As described in Narconon’s Wikipedia entry, Narconon facilities are known not only for attempting to win over new converts to Scientology, but also for treating all substance abuse addictions with a rather bizarre cocktail consisting mainly of vitamins and long hours in extremely hot saunas. Their Wiki entry documents multiple cases of accidental deaths at Narconon facilities, where some addicts reportedly died from overdoses of vitamins or neglect. 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 →


11
Apr 18

When Identity Thieves Hack Your Accountant

The Internal Revenue Service has been urging tax preparation firms to step up their cybersecurity efforts this year, warning that identity thieves and hackers increasingly are targeting certified public accountants (CPAs) in a bid to siphon oodles of sensitive personal and financial data on taxpayers. This is the story of a CPA in New Jersey whose compromise by malware led to identity theft and phony tax refund requests filed on behalf of his clients.

Last month, KrebsOnSecurity was alerted by security expert Alex Holden of Hold Security about a malware gang that appears to have focused on CPAs. The crooks in this case were using a Web-based keylogger that recorded every keystroke typed on the target’s machine, and periodically uploaded screenshots of whatever was being displayed on the victim’s computer screen at the time.

If you’ve never seen one of these keyloggers in action, viewing their output can be a bit unnerving. This particular malware is not terribly sophisticated, but nevertheless is quite effective. It not only grabs any data the victim submits into Web-based forms, but also captures any typing — including backspaces and typos as we can see in the screenshot below.

The malware records everything its victims type (including backspaces and typos), and frequently takes snapshots of the victim’s computer screen.

Whoever was running this scheme had all victim information uploaded to a site that was protected from data scraping by search engines, but the site itself did not require any form of authentication to view data harvested from victim PCs. Rather, the stolen information was indexed by victim and ordered by day, meaning anyone who knew the right URL could view each day’s keylogging record as one long image file.

Those records suggest that this particular CPA — “John,” a New Jersey professional whose real name will be left out of this story — likely had his computer compromised sometime in mid-March 2018 (at least, this is as far back as the keylogging records go for John).

It’s also not clear exactly which method the thieves used to get malware on John’s machine. Screenshots for John’s account suggest he routinely ignored messages from Microsoft and other third party Windows programs about the need to apply critical security updates.

Messages like this one — about critical security updates available for QuickBooks — went largely ignored, according to multiple screenshots from John’s computer.

More likely, however, John’s computer was compromised by someone who sent him a booby-trapped email attachment or link. When one considers just how frequently CPAs must need to open Microsoft Office and other files submitted by clients and potential clients via email, it’s not hard to imagine how simple it might be for hackers to target and successfully compromise your average CPA.

The keylogging malware itself appears to have been sold (or perhaps directly deployed) by a cybercriminal who uses the nickname ja_far. This individual markets a $50 keylogger product alongside a malware “crypting” service that guarantees his malware will be undetected by most antivirus products for a given number of days after it is used against a victim.

Ja_far’s sales threads for the keylogger used to steal tax and financial data from hundreds of John’s clients.

It seems likely that ja_far’s keylogger was the source of this data because at one point — early in the morning John’s time — the attacker appears to have accidentally pasted ja_far’s jabber instant messenger address into the victim’s screen instead of his own. In all likelihood, John’s assailant was seeking additional crypting services to ensure the keylogger remained undetected on John’s PC. A couple of minutes later, the intruder downloaded a file to John’s PC from file-sharing site sendspace.com.

The attacker apparently messing around on John’s computer while John was not sitting in front of the keyboard.

What I found remarkable about John’s situation was despite receiving notice after notice that the IRS had rejected many of his clients’ tax returns because those returns had already been filed by fraudsters, for at least two weeks John does not appear to have suspected that his compromised computer was likely the source of said fraud inflicted on his clients (or if he did, he didn’t share this notion with any of his friends or family via email).

Instead, John composed and distributed to his clients a form letter about their rejected returns, and another letter that clients could use to alert the IRS and New Jersey tax authorities of suspected identity fraud. Continue reading →


10
Apr 18

Adobe, Microsoft Push Critical Security Fixes

Adobe and Microsoft each released critical fixes for their products today, a.k.a “Patch Tuesday,” the second Tuesday of every month. Adobe updated its Flash Player program to resolve a half dozen critical security holes. Microsoft issued updates to correct at least 65 security vulnerabilities in Windows and associated software.

The Microsoft updates impact many core Windows components, including the built-in browsers Internet Explorer and Edge, as well as Office, the Microsoft Malware Protection Engine, Microsoft Visual Studio and Microsoft Azure.

The Malware Protection Engine flaw is one that was publicly disclosed earlier this month, and one for which Redmond issued an out-of-band (outside of Patch Tuesday) update one week ago.

That flaw, discovered and reported by Google’s Project Zero program, is reportedly quite easy to exploit and impacts the malware scanning capabilities for a variety of Microsoft anti-malware products, including Windows Defender, Microsoft Endpoint Protection and Microsoft Security Essentials.

Microsoft really wants users to install these updates as quickly as possible, but it might not be the worst idea to wait a few days before doing so: Quite often, problems with patches that may cause systems to end up in an endless reboot loop are reported and resolved with subsequent updates within a few days after their release. However, depending on which version of Windows you’re using it may be difficult to put off installing these patches.

Microsoft says by default, Windows 10 receives updates automatically, “and for customers running previous versions, we recommend they turn on automatic updates as a best practice.” Microsoft doesn’t make it easy for Windows 10 users to change this setting, but it is possible. For all other Windows OS users, if you’d rather be alerted to new updates when they’re available so you can choose when to install them, there’s a setting for that in Windows Update. In any case, don’t put off installing these updates too long. 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 →


5
Apr 18

Secret Service Warns of Chip Card Scheme

The U.S. Secret Service is warning financial institutions about a new scam involving the temporary theft of chip-based debit cards issued to large corporations. In this scheme, the fraudsters intercept new debit cards in the mail and replace the chips on the cards with chips from old cards. When the unsuspecting business receives and activates the modified card, thieves can start draining funds from the account.

Signs of a card with an old or invalid chip include heat damage around the chip or on the card, or a small hole in the plastic used to pry the chip off the card. Image: U.S. Secret Service.

According to an alert sent to banks late last month, the entire scheme goes as follows:

1. Criminals intercept mail sent from a financial institution to large corporations that contain payment cards, targeting debit payment cards with access to large amount of funds.

2. The crooks remove the chip from the debit payment card using a heat source that warms the glue.

3. Criminals replace the chip with an old or invalid chip and repackage the payment card for delivery.

4. Criminals place the stolen chip into an old payment card.

5. The corporation receives the debit payment card without realizing the chip has been replaced.

6. The corporate office activates the debit payment card; however, their payment card is inoperable thanks to the old chip.

7. Criminals use the payment card with the stolen chip for their personal gain once the corporate office activates the card. Continue reading →


4
Apr 18

Dot-cm Typosquatting Sites Visited 12M Times So Far in 2018

A story published here last week warned readers about a vast network of potentially malicious Web sites ending in “.cm” that mimic some of the world’s most popular Internet destinations (e.g. espn[dot]cm, aol[dot]cm and itunes[dot].cm) in a bid to bombard visitors with fake security alerts that can lock up one’s computer. If that piece lacked one key detail it was insight into just how many people were mistyping .com and ending up at one of these so-called “typosquatting” domains.

On March 30, an eagle-eyed reader noted that four years of access logs for the entire network of more than 1,000 dot-cm typosquatting domains were available for download directly from the typosquatting network’s own hosting provider. The logs — which include detailed records of how many people visited the sites over the past three years and from where — were deleted shortly after that comment was posted here, but not before KrebsOnSecurity managed to grab a copy of the entire archive for analysis.

The geographic distribution of 25,000 randomly selected Internet addresses (IP addresses) in the logs seen accessing the dot-cm typosquatting domains in February 2018. Batchgeo, the service used to produce this graphic, limits free lookups to 25,000, but the above image is likely still representative of the overall geographic distribution. Perhaps unsurprisingly, the largest share of traffic is coming from the United States.

Matthew Chambers, a security expert with whom this author worked on the original dot-cm typosquatting story published last week, analyzed the access logs from just the past three months and found the sites were visited approximately 12 million times during the first quarter of 2018.

Chambers said he combed through the logs and weeded out hits from Internet addresses that appeared to be bots or search engine scrapers. Here’s Chambers’ analysis of the 2018 access log data:

January 2018; 3,732,488 visitors
February 2018: 3,799,109 visitors
Mar 2018: 4,275,998 visitors

Total Jan-Mar 2018 is 11.8 million

Those figures suggest that the total number of visits to these typosquatting sites in the first quarter of 2018 was approximately 12 million, or almost 50 million hits per year. Certainly, not everyone visiting these sites will have the experience that Chambers’ users reported (being bombarded with misleading malware alerts and redirected to scammy and spammy Web sites), but it seems clear this network could make its operators a pretty penny regardless of the content that ends up getting served through it. Continue reading →