August, 2017


30
Aug 17

Twitter Bots Use Likes, RTs for Intimidation

I awoke this morning to find my account on Twitter (@briankrebs) had attracted almost 12,000 new followers overnight. Then I noticed I’d gained almost as many followers as the number of re-tweets (RTs) earned for a tweet I published on Tuesday. The tweet stated how every time I tweet something related to Russian President Vladimir Putin I get a predictable stream of replies that are in support of President Trump — even in cases when neither Trump nor the 2016 U.S. presidential campaign were mentioned.

This tweet about Putin generated more than 12,000 retweets and likes in a few hours.

This tweet about Putin generated more than 12,000 retweets and likes in a few hours.

Upon further examination, it appears that almost all of my new followers were compliments of a social media botnet that is being used to amplify fake news and to intimidate journalists, activists and researchers. The botnet or botnets appear to be targeting people who are exposing the extent to which sock puppet and bot accounts on social media platforms can be used to influence public opinion.

After tweeting about my new bounty of suspicious-looking Twitter friends I learned from my legitimate followers on Twitter that @briankrebs wasn’t alone and that several journalists and nonprofit groups that have written recently about bot-like activity on Twitter experienced something similar over the past few days.

These tweet and follow storms seem capable of tripping some kind of mechanism at Twitter that seeks to detect when accounts are suspected of artificially beefing up their follower counts by purchasing followers (for more on that dodgy industry, check out this post).

Earlier today, Daily Beast cybersecurity reporter Joseph Cox had his Twitter account suspended temporarily after the account was the beneficiary of hundreds of bot followers over a brief period on Tuesday. This likely was the goal in the campaign against my site as well.

Cox observed the same likely bot accounts that followed him following me and a short list of other users in the same order.

Cox observed the same likely bot accounts that followed him following me and a short list of other users in the same order.

“Right after my Daily Beast story about suspicious activity by pro-Kremlin bots went live, my own account came under attack,” Cox wrote.

Let that sink in for a moment: A huge collection of botted accounts — the vast majority of which should be easily detectable as such — may be able to abuse Twitter’s anti-abuse tools to temporarily shutter the accounts of real people suspected of being bots!

Overnight between Aug. 28 and 29, a large Twitter botnet took aim at the account for the Digital Forensic Research Lab, a project run by the Atlantic Council, a political think-tank based in Washington, D.C. In a post about the incident, DFRLab said the attack used fake accounts to impersonate and attack its members.

Those personal attacks — which included tweets and images lamenting the supposed death of DFR senior fellow Ben Nimmo — were then amplified and re-tweeted by tens of thousands of apparently automated accounts, according to a blost post published today by DFRLab.

Suspecting that DFRLab was now being followed by many more botted accounts that might retweet or otherwise react to any further tweets mentioning bot attacks, Nimmo cleverly composed another tweet about the bot attack — only this time CC’ing the @Twitter and @Twittersupport accounts. Sure enough, that sly tweet was retweeted by bots more than 73,000 times before the tweet storm died down.

tweetbotattack

“We considered that the bots had probably been programmed to react to a relatively simple set of triggers, most likely the words ‘bot attack’ and the @DFRLab handle,” Nimmo wrote. “To test the hypothesis, we posted a tweet mentioning the same words, and were retweeted over 500 times in nine minutes — something which, admittedly, does not occur regularly with our human followers.” Read more about the DFRLab episode here.

This week’s Twitter bot drama follows similar attacks on public interest groups earlier this month. On Aug. 19, the award-winning investigative journalism site ProPublica.org published the story, Leading Tech Companies Help Extremist Sites Monetize Hate.

On the morning of Tuesday, Aug. 22, several ProPublica reporters began receiving email bombs — email list subscription attacks that can inundate a targeted inbox with dozens or even hundreds of email list subscription confirmation requests per minute. These attacks are designed to deluge the victim’s inbox with so many subscription confirmation requests that it becomes extremely time-consuming to fish out the legitimate messages amid the dross.

On Wednesday ProPublica author Jeff Larson saw a tweet he sent about the email attacks get re-tweeted 1,200 times. Later that evening, senior reporting fellow Lauren Kirchner noticed a similar sized response to her tweet about how the subscription attack was affecting her ability to respond to messages.

On top of that, several ProPublica staffers suddenly gained about 500 new followers. On Thursday, ProPublica’s managing editor Eric Umansky noticed that a tweet accusing ProPublica of being an “alt-left #HateGroup and #FakeNews site funded by Soros” had received more than 23,000 re-tweets. Continue reading →


29
Aug 17

Beware of Hurricane Harvey Relief Scams

U.S. federal agencies are warning citizens anxious to donate money for those victimized by Hurricane Harvey to be especially wary of scam artists. In years past we’ve seen shameless fraudsters stand up fake charities and other bogus relief efforts in a bid to capitalize on public concern over an ongoing disaster. Here are some tips to help ensure sure your aid dollars go directly to those most in need.

charityscamThe Federal Trade Commission (FTC) issued an alert Monday urging consumers to be on the lookout for a potential surge in charity scams. The FTC advises those who wish to donate to stick to charities they know, and to be on the lookout for charities or relief Web sites that seem to have sprung up overnight in response to current events (such as houstonfloodrelief.net, registered on Aug. 28, 2017). Sometimes these sites are set up by well-meaning people with the best of intentions (however misguided), but it’s best not to take a chance.

The FTC also warns consumers not to assume that a charity message posted on social media is a legitimate, and urges folks to research the organization before donating by visiting charity evaluation sites such as Charity Navigator, Charity Watch, GuideStar, or the Better Business Bureau’s Wise Giving Alliance. The agency also reminds people who wish to donate via text message to confirm the number with the source before you donate.

From the US Computer Emergency Readiness Team (US-CERT) comes a reminder that malware purveyors frequently use natural disasters and other breaking news items of broad interest to trick people into clicking on malicious links or opening booby-trapped email attachments.

If anyone spots additional recently-registered Harvey-themed relief domains, please drop a note in the comments below.

Update, 11:42 p.m. ET: A reader pointed out a newly-registered domain — harveyfloodrelief[dot]org — that is currently requesting PayPal donations on behalf of Harvey victims.


28
Aug 17

Tech Firms Team Up to Take Down ‘WireX’ Android DDoS Botnet

A half dozen technology and security companies — some of them competitors — issued the exact same press release today. This unusual level of cross-industry collaboration caps a successful effort to dismantle ‘WireX,’ an extraordinary new crime machine comprising tens of thousands of hacked Android mobile devices that was used this month to launch a series of massive cyber attacks.

Experts involved in the takedown warn that WireX marks the emergence of a new class of attack tools that are more challenging to defend against and thus require broader industry cooperation to defeat.

This graphic shows the rapid growth of the WireX botnet in the first three weeks of August 2017.

This graphic shows the rapid growth of the WireX botnet in the first three weeks of August 2017.

News of WireX’s emergence first surfaced August 2, 2017, when a modest collection of hacked Android devices was first spotted conducting some fairly small online attacks. Less than two weeks later, however, the number of infected Android devices enslaved by WireX had ballooned to the tens of thousands.

More worrisome was that those in control of the botnet were now wielding it to take down several large websites in the hospitality industry — pelting the targeted sites with so much junk traffic that the sites were no longer able to accommodate legitimate visitors.

Experts tracking the attacks soon zeroed in on the malware that powers WireX: Approximately 300 different mobile apps scattered across Google‘s Play store that were mimicking seemingly innocuous programs, including video players, ringtones or simple tools such as file managers.

“We identified approximately 300 apps associated with the issue, blocked them from the Play Store, and we’re in the process of removing them from all affected devices,” Google said in a written statement. “The researchers’ findings, combined with our own analysis, have enabled us to better protect Android users, everywhere.”

Perhaps to avoid raising suspicion, the tainted Play store applications all performed their basic stated functions. But those apps also bundled a small program that would launch quietly in the background and cause the infected mobile device to surreptitiously connect to an Internet server used by the malware’s creators to control the entire network of hacked devices. From there, the infected mobile device would await commands from the control server regarding which Websites to attack and how.

A sampling of the apps from Google's Play store that were tainted with the WireX malware.

A sampling of the apps from Google’s Play store that were tainted with the WireX malware.

Experts involved in the takedown say it’s not clear exactly how many Android devices may have been infected with WireX, in part because only a fraction of the overall infected systems were able to attack a target at any given time. Devices that were powered off would not attack, but those that were turned on with the device’s screen locked could still carry on attacks in the background, they found.

“I know in the cases where we pulled data out of our platform for the people being targeted we saw 130,000 to 160,000 (unique Internet addresses) involved in the attack,” said Chad Seaman, a senior engineer at Akamai, a company that specializes in helping firms weather large DDoS attacks (Akamai protected KrebsOnSecurity from hundreds of attacks prior to the large Mirai assault last year).

The identical press release that Akamai and other firms involved in the WireX takedown agreed to publish says the botnet infected a minimum of 70,000 Android systems, but Seaman says that figure is conservative.

“Seventy thousand was a safe bet because this botnet makes it so that if you’re driving down the highway and your phone is busy attacking some website, there’s a chance your device could show up in the attack logs with three or four or even five different Internet addresses,” Seaman said in an interview with KrebsOnSecurity. “We saw attacks coming from infected devices in over 100 countries. It was coming from everywhere.”

BUILDING ON MIRAI

Security experts from Akamai and other companies that participated in the WireX takedown say the basis for their collaboration was forged in the monstrous and unprecedented distributed denial-of-service (DDoS) attacks launched last year by Mirai, a malware strain that seeks out poorly-secured “Internet of things” (IoT) devices such as security cameras, digital video recorders and Internet routers.

The first and largest of the Mirai botnets was used in a giant attack last September that knocked this Web site offline for several days. Just a few days after that — when the source code that powers Mirai was published online for all the world to see and use — dozens of copycat Mirai botnets emerged. Several of those botnets were used to conduct massive DDoS attacks against a variety of targets, leading to widespread Internet outages for many top Internet destinations.

Allison Nixon, director of security research at New York City-based security firm Flashpoint, said the Mirai attacks were a wake-up call for the security industry and a rallying cry for more collaboration.

“When those really large Mirai DDoS botnets started showing up and taking down massive pieces of Internet infrastructure, that caused massive interruptions in service for people that normally don’t deal with DDoS attacks,” Nixon said. “It sparked a lot of collaboration. Different players in the industry started to take notice, and a bunch of us realized that we needed to deal with this thing because if we didn’t it would just keep getting bigger and rampaging around.”

Mirai was notable not only for the unprecedented size of the attacks it could launch but also for its ability to spread rapidly to new machines. But for all its sheer firepower, Mirai is not a particularly sophisticated attack platform. Well, not in comparison to WireX, that is.

CLICK-FRAUD ORIGINS

According to the group’s research, the WireX botnet likely began its existence as a distributed method for conducting “click fraud,” a pernicious form of online advertising fraud that will cost publishers and businesses an estimated $16 billion this year, according to recent estimates. Multiple antivirus tools currently detect the WireX malware as a known click fraud malware variant.

The researchers believe that at some point the click-fraud botnet was repurposed to conduct DDoS attacks. While DDoS botnets powered by Android devices are extremely unusual (if not unprecedented at this scale), it is the botnet’s ability to generate what appears to be regular Internet traffic from mobile browsers that strikes fear in the heart of experts who specialize in defending companies from large-scale DDoS attacks. Continue reading →


24
Aug 17

Why It’s Still A Bad Idea to Post or Trash Your Airline Boarding Pass

An October 2015 piece published here about the potential dangers of tossing out or posting online your airline boarding pass remains one of the most-read stories on this site. One reason may be that the advice remains timely and relevant: A talk recently given at a Czech security conference advances that research and offers several reminders of how being careless with your boarding pass could jeopardize your privacy or even cause trip disruptions down the road.

In What’s In a Boarding Pass Barcode? A Lot, KrebsOnSecurity told the story of a reader whose friend posted a picture of a boarding pass on Facebook. The reader was able to use the airline’s Web site combined with data printed on the boarding pass to discover additional information about his friend. That data included details of future travel, the ability to alter or cancel upcoming flights, and a key component need to access the traveler’s frequent flyer account.

A search on Instagram for "boarding pass" returned 91,000+ results.

A search on Instagram for “boarding pass” returned 91,000+ results.

More recently, security researcher Michal Špaček gave a talk at a conference in the Czech Republic in which he explained how a few details gleaned from a picture of a friend’s boarding pass posted online give him the ability to view passport information on his friend via the airline’s Web site, and to change the password for another friend’s United Airlines frequent flyer account.

Working from a British Airways boarding pass that a friend posted to Instagram, Špaček found he could log in to the airline’s passenger reservations page using the six-digit booking code (a.k.a. PNR or passenger name record) and the last name of the passenger (both are displayed on the front of the BA boarding pass).

Once inside his friend’s account, Špaček saw he could cancel future flights, and view or edit his friend’s passport number, citizenship, expiration date and date of birth. In my 2015 story, I showed how this exact technique permitted access to the same information on Lufthansa customers (this still appears to be the case).

Špaček also reminds readers about the dangers of posting boarding pass barcodes or QR codes online, noting there are several barcode scanning apps and Web sites that can extract text data stored in bar codes and QR codes. Boarding pass bar codes and QR codes usually contain all of the data shown on the front of a boarding pass, and some boarding pass barcodes actually conceal even more personal information than what’s printed on the boarding pass.

As I noted back in 2015, United Airlines treats its customers’ frequent flyer numbers as secret access codes. For example, if you’re looking for your United Mileage Plus number, and you don’t have the original document or member card they mailed to you, good luck finding this information in your email correspondence with the company.

When United does include this code in correspondence, all but the last three characters are replaced with asterisks. The same is true with United’s boarding passes. However, the customer’s full Mileage Plus number is available if you take the time to decode the barcode on any United boarding pass.

Until very recently, if you knew the Mileage Plus number and last name of a United customer, you would have been able to reset their frequent flyer account password simply by guessing the multiple-choice answer to two secret questions about the customer. However, United has since added a third step — requiring the customer to click a link in an email that gets generated when someone successfully guesses the multiple-choice answers to the two secret questions. Continue reading →


22
Aug 17

Dumping Data from Deep-Insert Skimmers

I recently heard from a police detective who was seeking help identifying some strange devices found on two Romanian men caught maxing out stolen credit cards at local retailers. Further inspection revealed the devices to be semi-flexible data transfer wands that thieves can use to extract stolen ATM card data from “deep-insert skimmers,” wafer-thin fraud devices made to be hidden inside of the card acceptance slot on a cash machine.

The investigator agreed to share the photos if I kept his identity out of this story. He told KrebsOnSecurity that the two men were thought to be part of a crime gang active in the northeast United States, and that the almost 4-inch orange plastic wands allow thieves to download data from a deep insert skimmer. Depending on how the deep-insert skimmer is built, thieves may be able to use the wands to retrieve card data without having to remove the skimmer from the throat of the ATM.

Deep insert skimmers are different from typical insert skimmers in that they are placed in various positions within the card reader transport, behind the shutter of a motorized card reader and completely hidden from the consumer at the front of the ATM.

Here’s a look at these insert skimmer wands (for want of a better term):

These plastic wands allow thieves to extract stolen card data stored by insert skimmers.

These plastic wands allow thieves to extract stolen card data stored by insert skimmers.

This is what the wand (left) looks like when inserted into a deep-insert skimmer (right):

A data transfer wand inserted into a deep-insert skimmer.

A data transfer wand inserted into a deep-insert skimmer.

Continue reading →


18
Aug 17

Carbon Emissions: Oversharing Bug Puts Security Vendor Back in Spotlight

Last week, security firm DirectDefense came under fire for over-hyping claims that Cb Response, a cybersecurity product sold by competitor Carbon Black, was leaking proprietary data from customers who use it. Carbon Black responded that the bug identified by its competitor was a feature, and that customers were amply cautioned in advance about the potential privacy risks of using the feature. Now Carbon Black is warning that an internal review has revealed a wholly separate bug in Cb Response that could in fact result in some customers unintentionally sharing sensitive files.

cblogoAs noted in last week’s story, DirectDefense warned about a problem with Cb Response’s use of Google’s VirusTotal — a free tool that lets anyone submit a suspicious file and have it scanned against dozens of commercial anti-malware tools. There is also a paid version of VirusTotal that allows customers to examine any file uploaded to the service.

Specifically, DirectDefense claimed that Cb Response’s sharing of suspicious files with VirusTotal could expose sensitive data because VirusTotal allows paying customers to download any files submitted by other users. DirectDefense labeled the bug “the world’s largest pay-for-play data exfiltration botnet.”

Numerous industry analysts leapt to Carbon Black’s defense — with some even calling “bullshit” on the findings — pointing out that plenty of other vendors submit files through Virustotal and that DirectDefense was merely trying to besmirch a competitor’s product.

But earlier this week, Carbon Black began quietly notifying customers that an internal review of the claims revealed a completely different bug that could result in some benign customer files being miscategorized as executable files and inadvertently uploaded to Virustotal for scanning.

“On Thursday, we discovered a bug affecting a small percentage of our Cb Response customers,” said Mike Viscuso, co-founder and chief technology officer at Carbon Black. “Our review is still ongoing, but based on what we learned to date it requires a very specific customer configuration, and we have already taken steps to remediate the bug and protect our customers.” Continue reading →


18
Aug 17

Blowing the Whistle on Bad Attribution

The New York Times this week published a fascinating story about a young programmer in Ukraine who’d turned himself in to the local police. The Times says the man did so after one of his software tools was identified by the U.S. government as part of the arsenal used by Russian hackers suspected of hacking into the Democratic National Committee (DNC) last year. It’s a good read, as long as you can ignore that the premise of the piece is completely wrong.

The story, “In Ukraine, a Malware Expert Who Could Blow the Whistle on Russian Hacking,” details the plight of a hacker in Kiev better known as “Profexer,” who has reportedly agreed to be a witness for the FBI. From the story:

“Profexer’s posts, already accessible to only a small band of fellow hackers and cybercriminals looking for software tips, blinked out in January — just days after American intelligence agencies publicly identified a program he had written as one tool used in Russian hacking in the United States. American intelligence agencies have determined Russian hackers were behind the electronic break-in of the Democratic National Committee.”

The Times’ reasoning for focusing on the travails of Mr. Profexer comes from the “GRIZZLYSTEPPE” report, a collection of technical indicators or attack “signatures” published in December 2016 by the U.S. government that companies can use to determine whether their networks may be compromised by a number of different Russian cybercrime groups.

The only trouble is nothing in the GRIZZLYSTEPPE report said which of those technical indicators were found in the DNC hack. In fact, Prefexer’s “P.A.S. Web shell” tool — a program designed to insert a digital backdoor that lets attackers control a hacked Web site remotely — was specifically not among the hacking tools found in the DNC break-in.

The P.A.S. Web shell, as previously offered for free on the now-defunct site profexer[dot]name.

The P.A.S. Web shell, as previously offered for free on the now-defunct site profexer[dot]name.

That’s according to Crowdstrike, the company called in to examine the DNC’s servers following the intrusion. In a statement released to KrebsOnSecurity, Crowdstrike said it published the list of malware that it found was used in the DNC hack, and that the Web shell named in the New York Times story was not on that list.

Robert M. Lee is founder of the industrial cybersecurity firm Dragos, Inc. and an expert on the challenges associated with attribution in cybercrime. In a post on his personal blog, Lee challenged The Times on its conclusions.

“The GRIZZLYSTEPPE report has nothing to do with the DNC breach though and was a collection of technical indicators the government compiled from multiple agencies all working different Russian related threat groups,” Lee wrote.

“The threat group that compromised the DNC was Russian but not all Russian groups broke into the DNC,” he continued. “The GRIZZLYSTEPPE report was also highly criticized for its lack of accuracy and lack of a clear message and purpose. I covered it here on my blog but that was also picked up by numerous journalists and covered elsewhere [link added]. In other words, there’s no excuse for not knowing how widely criticized the GRIZZLYSTEPPE report was before citing it as good evidence in a NYT piece.”

Perhaps in response to Lee’s blog post, The Times issued a correction to the story, re-writing the above-quoted and indented paragraph to read:

“It is the first known instance of a living witness emerging from the arid mass of technical detail that has so far shaped the investigation into the election hacking and the heated debate it has stirred. The Ukrainian police declined to divulge the man’s name or other details, other than that he is living in Ukraine and has not been arrested.”

[Side note: Profexer may well have been doxed by this publication just weeks after the GRIZZLYSTEPPE report was released.] Continue reading →


10
Aug 17

Beware of Security by Press Release

On Wednesday, the security industry once again witnessed an all-too-familiar cycle: I call it “security by press release.” It goes a bit like this: A security firm releases a report claiming to have unearthed a major flaw in a competitor’s product; members of the trade press uncritically republish the claims without adding much clarity or waiting for responses from the affected vendor; blindsided vendor responds in a blog post showing how the issue is considerably less dire than originally claimed.

At issue are claims made by Denver-based security company DirectDefense, which published a report this week warning that Cb Response — a suite of security tools sold by competitor Carbon Black (formerly Bit9) — was leaking potentially sensitive and proprietary data from customers who use its product.

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DirectDefense warned about a problem with Cb Response’s use of “a cloud-based multiscanner” to scan suspicious files for malware. DirectDefense didn’t name the scanner in question, but it’s Google’s VirusTotal — a free tool that lets anyone submit a suspicious file and have it scanned against dozens of commercial anti-malware tools. There’s also a paid version of VirusTotal that allows customers to examine any file uploaded to the service.

Specifically, DirectDefense claimed that Cb Response’s sharing of suspicious files with VirusTotal could expose sensitive data because VirusTotal allows paying customers to download any files submitted by other users. This is the full extent of the “vulnerability” that DirectDefense labeled “the world’s largest pay-for-play data exfiltration botnet.”

Carbon Black responded with its own blog post noting that the feature DirectDefense warned about was not turned on by default, and that Carbon Black informs customers of the privacy risks that may be associated with sharing files with VirusTotal.

ANALYSIS

Adrian Sanabria, a security expert and co-founder of Savage Security, published a blog post that called “bullshit” on DirectDefense’s findings, noting that the company inexplicably singles out a competitor when many other security firms similarly allow customers to submit files to VirusTotal.

“Dozens of other security vendors either have an option to automatically submit binaries (yes, whole binaries, not just the hash) to VirusTotal or do it without the customers knowledge altogether,” Sanabria wrote. “In singling out Carbon Black, DirectDefense opens itself up to criticism and closer scrutiny.”

Such as shilling for a partner firm (Cylance) that stands to gain from taking Carbon Black down a few notches in the public eye, Sanabria observed [link added].

“I personally don’t believe DirectDefense is a shill for Cylance, but in singling out one of many vendors that do the same thing, they’ve stepped into a classic PR gaffe that makes them look like one,” he wrote. Continue reading →


9
Aug 17

Alleged vDOS Operators Arrested, Charged

Two young Israeli men alleged by this author to have co-founded vDOS — until recently the largest and most profitable cyber attack-for-hire service online — were arrested and formally indicted this week in Israel on conspiracy and hacking charges.

On Sept. 8, 2016, KrebsOnSecurity published a story about the hacking of vDOS, a service that attracted tens of thousands of paying customers and facilitated more than two million distributed denial-of-service (DDoS) attacks over the four year period it was in business.

That story named two then 18-year-old Israelis — Yarden “applej4ck” Bidani and Itay “p1st” Huri — as the likely owners and operators of vDOS. Within hours of that story’s publication the two were detained by Israeli police, placed on house arrest for 10 days, and forbidden from using the Internet for a month.

vDOS as it existed on Sept. 8, 2016.

vDOS as it existed on Sept. 8, 2016.

On Tuesday, Israeli prosecutors announced they had formally arrested and charged two 19-year-olds with conspiring to commit a felony, prohibited activities, tampering with or disrupting a computer, and storing or disseminating false information. A statement from a spokesman for the Israeli state attorney’s office said prosecutors couldn’t name the accused because their alleged crimes were committed while they were minors.

But a number of details match perfectly with previous reporting on Bidani and Huri. As noted in the original Sept. 2016 expose’ on vDOS’s alleged founders, Israeli prosecutors say the two men made more than $600,000 in two of the four years the service was in operation. vDOS was shuttered for good not longer after Bidani and Huri’s initial detention in Sept. 2016.

“The defendants were constantly improving the attack code and finding different network security weaknesses that would enable them to offer increased attack services that could overcome existing defenses and create real damage to servers and services worldwide,” Israeli prosecutors alleged of the accused and their enterprise. Continue reading →