Flash Player is Dead, Long Live Flash Player!

August 2, 2017

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

New Bill Seeks Basic IoT Security Standards

August 1, 2017

Lawmakers in the U.S. Senate today introduced a bill that would set baseline security standards for the government’s purchase and use of a broad range of Internet-connected devices, including computers, routers and security cameras. The legislation, which also seeks to remedy some widely-perceived shortcomings in existing cybercrime law, was developed in direct response to a series of massive cyber attacks in 2016 that were fueled for the most part by poorly-secured “Internet of Things” (IoT) devices.

iotc

The IoT Cybersecurity Improvement Act of 2017 seeks to use the government’s buying power to signal the basic level of security that IoT devices sold to Uncle Sam will need to have. For example, the bill would require vendors of Internet-connected devices purchased by the federal government make sure the devices can be patched when security updates are available; that the devices do not use hard-coded (unchangeable) passwords; and that vendors ensure the devices are free from known vulnerabilities when sold.

The bill, introduced by Sens. Steve Daines (R-Mont.), Cory Gardner (R-Colo.), Mark Warner (D-Va.) and Ron Wyden (D-Ore.), directs the White House Office of Management and Budget (OMB) to develop alternative network-level security requirements for devices with limited data processing and software functionality. In addition, it requires each executive agency to inventory all Internet-connected devices in use by the agency.

The bill’s provisions would seem to apply to virtually any device that has an Internet connection and can transmit data. Under the proposal, an IoT device has a fairly broad definition, being described as “a physical object that is capable of connecting to and is in regular connection with the Internet;” and one that “has computer processing capabilities that can collect, send or receive data.” Continue reading

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Suspended Sentence for Mirai Botmaster Daniel Kaye

July 28, 2017

Last month, KrebsOnSecurity identified U.K. citizen Daniel Kaye as the likely real-life identity behind a hacker responsible for clumsily wielding a powerful botnet built on Mirai, a malware strain that enslaves poorly secured Internet of Things (IoT) devices for use in large-scale online attacks. Today, a German court issued a suspended sentence for Kaye, who now faces cybercrime charges in the United Kingdom.

Daniel Kaye's Facebook profile page.

Daniel Kaye’s Facebook profile page.

In February 2017, authorities in the United Kingdom arrested a 29-year-old U.K. man on suspicion of knocking more than 900,000 Germans offline in a Mirai attack in November 2016. Shortly after that 2016 attack, a hacker using the nickname “Bestbuy” told reporters he was responsible for the outage, apologizing for the incident.

Prosecutors in Europe had withheld Kaye’s name from the media throughout the trial. But a court in Germany today confirmed Kaye’s identity as it handed down a suspended sentence on charges stemming from several failed attacks from his Mirai botnet — which nevertheless caused extensive internet outages for ISPs in the U.K., Germany and Liberia last year.

On July 5, KrebsOnSecurity published Who is the GovRAT Author and Mirai Botmaster BestBuy. The story followed clues from reports produced by a half-dozen security firms that traced common clues between this BestBuy nickname and an alter-ego, “Spiderman.”

Both identities were connected to the sale of an espionage tool called GovRAT, which is documented to have been used in numerous cyber espionage campaigns against governments, financial institutions, defense contractors and more than 100 corporations.

That July 5 story traced a trail of digital clues left over 10 years back to Daniel Kaye, a 29-year-old man who had dual U.K. and Israeli citizenship and who was engaged to be married to a U.K. woman.

A “mind map” tracing some of the research mentioned in this post.

Last week, a 29-year-old identified by media only as “Daniel K” pleaded guilty in a German court for launching the attacks that knocked 900,000 Deutsche Telekom customers offline. Prosecutors said Daniel K sold access to his Mirai botnet as an attack-for-hire service.

The defendant reportedly told the court that the incident was the biggest mistake of his life, and that he took money in exchange for launching attacks in order to help start a new life with his fiancee. Continue reading

Gas Pump Skimmer Sends Card Data Via Text

July 27, 2017

Skimming devices that crooks install inside fuel station gas pumps frequently rely on an embedded Bluetooth component allowing thieves to collect stolen credit card data from the pumps wirelessly with any mobile device. The downside of this approach is that Bluetooth-based skimmers can be detected by anyone else with a mobile device. Now, investigators in the New York say they are starting to see pump skimmers that use cannibalized cell phone components to send stolen card data via text message.

Skimmers that transmit stolen card data wirelessly via GSM text messages and other mobile-based communications methods are not new; they have been present — if not prevalent — in ATM skimming devices for ages.

But this is the first instance KrebsOnSecurity is aware of in which such SMS skimmers have been found inside gas pumps, and that matches the experience of several states hardest hit by pump skimming activity.

The beauty of the GSM-based skimmer is that it can transmit stolen card data wirelessly via text message, meaning thieves can receive real-time transmissions of the card data anywhere in the world — never needing to return to the scene of the crime. That data can then be turned into counterfeit physical copies of the cards.

Here’s a look at a new skimmer pulled from compromised gas pumps at three different filling stations in New York this month. Like other pump skimmers, this device was hooked up to the pump’s internal power, allowing it to operate indefinitely without relying on batteries.

A GSM-based card skimmer found embedded in a gas pump in the northeastern United States.

A GSM-based card skimmer found embedded in a gas pump in the northeastern United States.

It may be difficult to see from the picture above, but the skimmer includes a GSM-based device with a SIM card produced by cellular operator T-Mobile. The image below shows the other side of the pump skimmer, with the SIM card visible in the upper right corner of the circuitboard:

The reverse side of this GSM-based pump skimmer shows a SIM card from T-Mobile.

The reverse side of this GSM-based pump skimmer shows a SIM card from T-Mobile.

It’s not clear what type of mobile device was used in this skimmer, and the police officer who shared these images with KrebsOnSecurity said the forensic analysis of the device was ongoing. Continue reading

How a Citadel Trojan Developer Got Busted

July 25, 2017

A U.S. District Court judge in Atlanta last week handed a five year prison sentence to Mark Vartanyan, a Russian hacker who helped develop and sell the once infamous and widespread Citadel banking trojan. This fact has been reported by countless media outlets, but far less well known is the fascinating backstory about how Vartanyan got caught.

For several years, Citadel ruled the malware scene for criminals engaged in stealing online banking passwords and emptying bank accounts. U.S. prosecutors say Citadel infected more than 11 million computers worldwide, causing financial losses of at least a half billion dollars.

Like most complex banking trojans, Citadel was marketed and sold in secluded, underground cybercrime markets. Often the most time-consuming and costly aspect of malware sales and development is helping customers with any tech support problems they may have in using the crimeware.

In light of that, one innovation that Citadel brought to the table was to crowdsource some of this support work, easing the burden on the malware’s developers and freeing them up to spend more time improving their creations and adding new features.

Citadel users discuss the merits of including a module to remove other parasites from host PCs.

Citadel users discuss the merits of including a module to remove other parasites from host PCs.

Citadel boasted an online tech support system for customers designed to let them file bug reports, suggest and vote on new features in upcoming malware versions, and track trouble tickets that could be worked on by the malware developers and fellow Citadel users alike. Citadel customers also could use the system to chat and compare notes with fellow users of the malware.

It was this very interactive nature of Citadel’s support infrastructure that FBI agents would ultimately use to locate and identify Vartanyan, who went by the nickname “Kolypto.” The nickname of the core seller of Citadel was “Aquabox,” and the FBI was keen to identify Aquabox and any programmers he’d hired to help develop Citadel.

In June 2012, FBI agents bought several licenses of Citadel from Aquabox, and soon the agents were suggesting tweaks to the malware that they could use to their advantage. Posing as an active user of the malware, FBI agents informed the Citadel developers that they’d discovered a security vulnerability in the Web-based interface that Citadel customers used to keep track of and collect passwords from infected systems (see screenshot below).

A screenshot of the Citadel botnet panel.

A screenshot of the Web-based Citadel botnet control panel.

Continue reading

Exclusive: Dutch Cops on AlphaBay ‘Refugees’

July 20, 2017

Following today’s breaking news about U.S. and international authorities taking down the competing Dark Web drug bazaars AlphaBay and Hansa Market, KrebsOnSecurity caught up with the Dutch investigators who took over Hansa on June 20, 2017. When U.S. authorities shuttered AlphaBay on July 5, police in The Netherlands saw a massive influx of AlphaBay refugees who were unwittingly fleeing directly into the arms of investigators. What follows are snippets from an exclusive interview with Petra Haandrikman, team leader of the Dutch police unit that infiltrated Hansa.

Vendors on both AlphaBay and Hansa sold a range of black market items — most especially controlled substances like heroin. According to the U.S. Justice Department, AlphaBay alone had some 40,000 vendors who marketed a quarter-million sales listings for illegal drugs to more than 200,000 customers. The DOJ said that as of earlier this year, AlphaBay had 238 vendors selling heroin. Another 122 vendors advertised Fentanyl, an extremely potent synthetic opioid that has been linked to countless overdoses and deaths.

In our interview, Haandrikman detailed the dual challenges of simultaneously dealing with the exodus of AlphaBay users to Hansa and keeping tabs on the giant increase in new illicit drug orders that were coming in daily as a result.

The profile and feedback of a top AlphaBay vendor.

The profile and feedback of a top AlphaBay vendor. Image: ShadowDragon.io

KrebsOnSecurity (K): Talk a bit about how your team was able to seize control over Hansa.

Haandrikman (H): When we knew the FBI was working on AlphaBay, we thought ‘What’s better than if they come to us?’ The FBI wanted [the AlphaBay takedown] to look like an exit scam [where the proprietors of a dark web marketplace suddenly abscond with everyone’s money]. And we knew a lot of vendors on AlphaBay would probably come over to Hansa when AlphaBay was closed.

K: Where was Hansa physically based?

H: We knew the Hansa servers were in Lithuania, so we sent an MLAT (mutual legal assistance treaty) request to Lithuania and requested if we could proceed with our planned actions in their country. They were very willing to help us in our investigations.

K: So you made a copy of the Hansa servers?

H: We gained physical access to the machines in Lithuania, and were able to set up some clustering between the [Hansa] database servers in Lithuania and servers we were running in our country. With that, we were able to get a real time copy of the Hansa database, and then copy over the Web site code itself.

K: Did you have to take Hansa offline for a while during this process?

H: No, it didn’t really go offline. We were able to create our own copy of the site that was running on servers in the Netherlands. So there were two copies of the site running simultaneously.

The now-defunct Hansa Market.

The now-defunct Hansa Market.

K: At a press conference on this effort at the U.S. Justice Department in Washington, D.C. today, Rob Wainwright, director of the European law enforcement organization Europol, detailed how the closure of AlphaBay caused a virtual stampede of former AlphaBay buyers and sellers taking their business to Hansa Market. Tell us more about what that influx was like, and how you handled it.

H: Yes, we called them “AlphaBay refugees.” It wasn’t the technical challenge that caused problems. Because this was a police operation, we wanted to keep up with the orders to see if there were any large amounts [of drugs] being ordered to one place, [so that] we could share information with our law enforcement partners internationally.

K: How exactly did you deal with that? Were you able to somehow slow down the orders coming in?

H: We just closed registration on Hansa for new users for a few days. So there was a temporary restriction for being able to register on the site, which slowed down the orders each day to make sure that we could cope with the orders that were coming in.

K: Did anything unexpected happen as a result?

H: Some people started selling their Hansa accounts on Reddit. I read somewhere that one Hansa user sold his account for $40. The funny part about that was that sale happened about five minutes before we re-opened registration. There was a lot of frustration from ex-AlphaBay users that weren’t allowed to register on the site. But we also got defended by the Hansa community on social media, who said it was a great decision by us to educate certain AlphaBay users on Hansa etiquette, which doesn’t allow the sale of things permitted on AlphaBay and other dark markets, such as child pornography and firearms.

A message from Dutch authorities listing the top dark market vendors by nickname.

A message from Dutch authorities listing the top dark market vendors by nickname.

Continue reading

After AlphaBay’s Demise, Customers Flocked to Dark Market Run by Dutch Police

July 20, 2017

Earlier this month, news broke that authorities had seized the Dark Web marketplace AlphaBay, an online black market that peddled everything from heroin to stolen identity and credit card data. But it wasn’t until today, when the U.S. Justice Department held a press conference to detail the AlphaBay takedown that the other shoe dropped: Police in The Netherlands for the past month have been operating Hansa Market, a competing Dark Web bazaar that enjoyed a massive influx of new customers immediately after the AlphaBay takedown.

The normal home page for the dark Web market Hansa has been replaced by this message from U.S. law enforcement authorities.

The normal home page for the dark Web market Hansa has been replaced by this message from U.S. law enforcement authorities.

U.S. Attorney General Jeff Sessions called the AlphaBay closure “the largest takedown in world history,” targeting some 40,000 vendors who marketed a quarter-million listings for illegal drugs to more than 200,000 customers.

“By far, most of this activity was in illegal drugs, pouring fuel on the fire of a national drug epidemic,” Sessions said. “As of earlier this year, 122 vendors advertised Fentanyl. 238 advertised heroin. We know of several Americans who were killed by drugs on AlphaBay.”

Andrew McCabe, acting director of the FBI, said AlphaBay was roughly 10 times the size of the Silk Road, a similar dark market that was shuttered in a global law enforcement sting in October 2013.

As impressive as those stats may be, the real coup in this law enforcement operation became evident when Rob Wainwright, director of the European law enforcement organization Europol, detailed how the closure of AlphaBay caused a virtual stampede of former AlphaBay buyers and sellers taking their business to Hansa Market, which had been quietly and completely taken over by Dutch police one month earlier — on June 20.

“What this meant…was that we could identify and disrupt the regular criminal activity that was happening on Hansa Market but also sweep up all of those new users that were displaced from AlphaBay and looking for a new trading plot form for their criminal activities,” Wainwright told the media at today’s press conference, which seemed more interested in asking Attorney General Sessions about a recent verbal thrashing from President Trump.

“In fact, they flocked to Hansa in droves,” Wainwright continued. “We recorded an eight times increase in the number of human users on Hansa immediately following the takedown of AlphaBay. Since the undercover operation to take over Hansa market by the Dutch Police, usernames and passwords of thousands of buyers and sellers of illicit commodities have been identified and are the subject of follow-up investigations by Europol and our partner agencies.” Continue reading

Trump Hotels Hit By 3rd Card Breach in 2 Years

July 19, 2017

Maybe some of you missed this amid all the breach news recently (I know I did), but Trump International Hotels Management LLC last week announced its third credit-card data breach in the past two years. I thought it might be useful to see these events plotted on a timeline, because it suggests that virtually anyone who used a credit card at a Trump property in the past two years likely has had their card data stolen and put on sale in the cybercrime underground as a result.

On May 2, 2017, KrebsOnSecurity broke the story that travel industry giant Sabre Corp. experienced a significant breach of its payment and customer data tied to bookings processed through a reservations system that serves more than 32,000 hotels and other lodging establishments. Last week, Trump International Hotels disclosed the SABRE breach impacted at least 13 Trump Hotel properties between August 2016 and March 2017. Trump Hotels said it was first notified of the breach on June 5.

A timeline of Trump Hotels’ credit card woes over the past two years. Click to enlarge.

According to Verizon‘s latest annual Data Breach Investigations Report (DBIR), malware attacks on point-of-sale systems used at front desk and hotel restaurant systems “are absolutely rampant” in the hospitality sector. Accommodation was the top industry for point-of-sale intrusions in this year’s data, with 87% of breaches within that pattern.

Other hotel chains that disclosed this past week getting hit in the Sabre breach include 11 Hard Rock properties (another chain hit by multiple card breach incidents); Four Seasons Hotels and Resorts; and at least two dozen Loews Hotels in the United States and Canada.

ANALYSIS/RANT

Given its abysmal record of failing to protect customer card data, you might think the hospitality industry would be anxious to assuage guests who may already be concerned that handing over their card at the hotel check-in desk also means consigning that card to cybercrooks (e.g. at underground carding shops like Trumps Dumps).

However, so far this year I’ve been hard-pressed to find any of the major hotel chains that accept more secure chip-based cards, which are designed to make card data stolen by point-of-sale malware and skimmers much more difficult to turn into counterfeit cards. I travel quite a bit — at least twice a month — and I have yet to experience a single U.S.-based hotel in the past year asking me to dip my chip-based card as opposed to swiping it.

A carding shop that sells stolen credit cards and invokes 45's likeness and name. No word yet on whether this cybercriminal store actually sold any cards stolen from Trump Hotel properties.

A carding shop that sells stolen credit cards and invokes 45’s likeness and name. No word yet on whether this cybercriminal store actually sold any cards stolen from Trump Hotel properties.

True, chip cards alone aren’t going to solve the whole problem. Hotels and other merchants that implement the ability to process chip cards still need to ensure the data is encrypted at every step of the transaction (known as “point-to-point” or “end-to-end” encryption). Investing in technology like tokenization — which allows merchants to store a code that represents the customer’s card data instead of the card data itself — also can help companies become less of a target.

Maybe it wouldn’t be so irksome if those of us concerned about security or annoyed enough at getting our cards replaced three or four times a year due to fraud could stay at a major hotel chain in the United States and simply pay with cash. But alas, we’re talking about an industry that essentially requires customers to pay by credit card.

Well, at least I’ll continue to accrue reward points on my credit card that I can use toward future rounds of Russian roulette with the hotel’s credit card systems.

It’s bad enough that cities and states routinely levy huge taxes on lodging establishments (the idea being the tax is disproportionately paid by people who don’t vote or live in the area); now we have the industry-wide “carder tax” conveniently added to every stay.

What’s the carder tax you ask? It’s the sense of dread and the incredulous “really?” that wells up when one watches his chip card being swiped yet again at the check-out counter.

It’s the time wasted on the phone with your bank trying to sort out whether you really made all those fraudulent purchases, and then having to enter your new card number at all those sites and services where the old one was stored. It’s that awkward moment when the waiter says in front of your date or guests that your card has been declined. Continue reading

Experts in Lather Over ‘gSOAP’ Security Flaw

July 18, 2017

Axis Communications — a maker of high-end security cameras whose devices can be found in many high-security areas — recently patched a dangerous coding flaw in virtually all of its products that an attacker could use to remotely seize control over or crash the devices.

The problem wasn’t specific to Axis, which seems to have reacted far more quickly than competitors to quash the bug. Rather, the vulnerability resides in open-source, third-party computer code that has been used in countless products and technologies (including a great many security cameras), meaning it may be some time before most vulnerable vendors ship out a fix — and even longer before users install it.cam2cam

At issue is a flaw in a bundle of reusable code (often called a “code library“) known as gSOAP, a widely-used toolkit that software or device makers can use so that their creations can talk to the Internet (or “parse XML” for my geek readers). By some estimates, there are hundreds — if not thousands — of security camera types and other so-called “Internet of Things”(IoT) devices that rely upon the vulnerable gSOAP code.

By exploiting the bug, an attacker could force a vulnerable device to run malicious code, block the owner from viewing any video footage, or crash the system. Basically, lots of stuff you don’t want your pricey security camera system to be doing.

Genivia, the company that maintains gSOAP, released an update on June 21, 2017 that fixes the flaw. In short order, Axis released a patch to plug the gSOAP hole in nearly 250 of its products.

Genivia chief executive Robert Van Engelen said his company has already reached out to all of its customers about the issue. He said a majority of customers use the gSOAP software to develop products, but that mostly these are client-side applications or non-server applications that are not affected by this software crash issue.

“It’s a crash, not an exploit as far as we know,” Van Engelen said. “I estimate that over 85% of the applications are unlikely to be affected by this crash issue.”

Still, there are almost certainly dozens of other companies that use the vulnerable gSOAP code library and haven’t (or won’t) issue updates to fix this flaw, says Stephen Ridley, chief technology officer and founder of Senrio — the security company that discovered and reported the bug. What’s more, because the vulnerable code is embedded within device firmware (the built-in software that powers hardware), there is no easy way for end users to tell if the firmware is affected without word one way or the other from the device maker.

“It is likely that tens of millions of products — software products and connected devices — are affected by this,” Ridley said.

“Genivia claims to have more than 1 million downloads of gSOAP (most likely developers), and IBM, Microsoft, Adobe and Xerox as customers,” the Senrio report reads. “On Sourceforge, gSOAP was downloaded more than 1,000 times in one week, and 30,000 times in 2017. Once gSOAP is downloaded and added to a company’s repository, it’s likely used many times for different product lines.”
Continue reading

Porn Spam Botnet Has Evil Twitter Twin

July 16, 2017

Last month KrebsOnSecurity published research into a large distributed network of apparently compromised systems being used to relay huge blasts of junk email promoting “online dating” programs — affiliate-driven schemes traditionally overrun with automated accounts posing as women. New research suggests that another bot-promoting botnet of more than 80,000 automated female Twitter accounts has been pimping the same dating scheme and prompting millions of clicks from Twitter users in the process.

One of the 80,000+ Twitter bots ZeroFOX found that were enticing male Twitter users into viewing their profile pages.

One of the 80,000+ Twitter bots ZeroFOX found that were enticing male Twitter users into viewing their profile pages.

Not long after I published Inside a Porn-Pimping Spam Botnet, I heard from researchers at ZeroFOX, a security firm that helps companies block attacks coming through social media.

Zack Allen, manager of threat operations at ZeroFOX, said he had a look at some of the spammy, adult-themed domains being promoted by the botnet in my research and found they were all being promoted through a botnet of bogus Twitter accounts.

Those phony Twitter accounts all featured images of attractive or scantily-clad women, and all were being promoted via suggestive tweets, Allen said.

Anyone who replied was ultimately referred to subscription-based online dating sites run by Deniro Marketing, a company based in California. This was the same company that was found to be the beneficiary of spam from the porn botnet I’d written about in June. Deniro did not respond to requests for comment.

“We’ve been tracking this thing since February 2017, and we concluded that the social botnet controllers are probably not part of Deniro Marketing, but most likely are affiliates,” Allen said.

ZeroFOX found more than 86,262 Twitter accounts were responsible for more than 8.6 million posts on Twitter promoting porn-based sites, many of them promoting domains in a swath of Internet address space owned by Deniro Marketing (ASN19884).

Allen said 97.4% of bot display names had the pattern “Firstname Surname” with the first letters of each name capitalized, and each name separated by a single whitespace character that corresponded to common female names.

An analysis of the Twitter bot names used in the scheme. Graphic: ZeroFOX.

An analysis of the Twitter bot names used in the scheme. Graphic: ZeroFOX.

The accounts advertise adult content by routinely injecting links from their twitter profiles to a popular hashtag, or by @-mentioning a popular user or influencer on Twitter. Those profile links are shortened with Google’s goo.gl link shortening service, which then redirects to a free hosting domain in the dot-tk (.tk) domain space (.tk is the country code for Tokelau — a group of atolls in the South Pacific).

From there the system is smart enough to redirect users back to Twitter if they appear to be part of any automated attempt to crawl the links (e.g. by using site download and mirroring tools like cURL), the researchers found. They said this was likely a precaution on the part of the spammers to avoid detection by automated scanners looking for bot activity on Twitter. Requests from visitors who look like real users responding to tweets are redirected to the porn spam sites.

Because the links promoted by those spammy Twitter accounts all abused short link services from Twitter and Google, the researchers were able to see that this entire botnet has generated more than 30 million unique clicks from February to June 2017. Continue reading