Microsoft Patches Six Zero-Day Security Holes

June 8, 2021
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Microsoft today released another round of security updates for Windows operating systems and supported software, including fixes for six zero-day bugs that malicious hackers already are exploiting in active attacks.

June’s Patch Tuesday addresses just 49 security holes — about half the normal number of vulnerabilities lately. But what this month lacks in volume it makes up for in urgency: Microsoft warns that bad guys are leveraging a half-dozen of those weaknesses to break into computers in targeted attacks.

Among the zero-days are:

–CVE-2021-33742, a remote code execution bug in a Windows HTML component.
–CVE-2021-31955, an information disclosure bug in the Windows Kernel
–CVE-2021-31956, an elevation of privilege flaw in Windows NTFS
–CVE-2021-33739, an elevation of privilege flaw in the Microsoft Desktop Window Manager
–CVE-2021-31201, an elevation of privilege flaw in the Microsoft Enhanced Cryptographic Provider
–CVE-2021-31199, an elevation of privilege flaw in the Microsoft Enhanced Cryptographic Provider

Kevin Breen, director of cyber threat research at Immersive Labs, said elevation of privilege flaws are just as valuable to attackers as remote code execution bugs: Once the attacker has gained an initial foothold, he can move laterally across the network and uncover further ways to escalate to system or domain-level access.

“This can be hugely damaging in the event of ransomware attacks, where high privileges can enable the attackers to stop or destroy backups and other security tools,” Breen said. “The ‘exploit detected’ tag means attackers are actively using them, so for me, it’s the most important piece of information we need to prioritize the patches.” Continue reading →

Justice Dept. Claws Back $2.3M Paid by Colonial Pipeline to Ransomware Gang

June 7, 2021
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The U.S. Department of Justice said today it has recovered $2.3 million worth of Bitcoin that Colonial Pipeline paid to ransomware extortionists last month. The funds had been sent to DarkSide, a ransomware-as-a-service syndicate that disbanded after a May 14 farewell message to affiliates saying its Internet servers and cryptocurrency stash were seized by unknown law enforcement entities.

On May 7, the DarkSide ransomware gang sprang its attack against Colonial, which ultimately paid 75 Bitcoin (~$4.4 million) to its tormentors. The company said the attackers only hit its business IT networks — not its pipeline security and safety systems — but that it shut the pipeline down anyway as a precaution [several publications noted Colonial shut down its pipeline because its billing system was impacted, and it had no way to get paid].

On or around May 14, the DarkSide representative on several Russian-language cybercrime forums posted a message saying the group was calling it quits.

“Servers were seized, money of advertisers and founders was transferred to an unknown account,” read the farewell message. “Hosting support, apart from information ‘at the request of law enforcement agencies,’ does not provide any other information.”

A message from the DarkSide and REvil ransomware-as-a-service cybercrime affiliate programs.

Many security experts said they suspected DarkSide was just laying low for a while thanks to the heat from the Colonial attack, and that the group would re-emerge under a new banner in the coming months. And while that may be true, the seizure announced today by the DOJ certainly supports the DarkSide administrator’s claims that their closure was involuntary.

Security firms have suspected for months that the DarkSide gang shares some leadership with that of REvil, a.k.a. Sodinokibi, another ransomware-as-a-service platform that closed up shop in 2019 after bragging that it had extorted more than $2 billion from victims. That suspicion was solidified further when the REvil administrator added his comments to the announcement about DarkSide’s closure (see screenshot above).

First surfacing on Russian language hacking forums in August 2020, DarkSide is a ransomware-as-a-service platform that vetted cybercriminals can use to infect companies with ransomware and carry out negotiations and payments with victims. DarkSide says it targets only big companies, and forbids affiliates from dropping ransomware on organizations in several industries, including healthcare, funeral services, education, public sector and non-profits.

According to an analysis published May 18 by cryptocurrency security firm Elliptic, 47 cybercrime victims paid DarkSide a total of $90 million in Bitcoin, putting the average ransom payment of DarkSide victims at just shy of $2 million. Continue reading →

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Adventures in Contacting the Russian FSB

June 7, 2021
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KrebsOnSecurity recently had occasion to contact the Russian Federal Security Service (FSB), the Russian equivalent of the U.S. Federal Bureau of Investigation (FBI). In the process of doing so, I encountered a small snag: The FSB’s website said in order to communicate with them securely, I needed to download and install an encryption and virtual private networking (VPN) appliance that is flagged by at least 20 antivirus products as malware.

The FSB headquarters at Lubyanka Square, Moscow. Image: Wikipedia.

The reason I contacted the FSB — one of the successor agencies to the Russian KGB — ironically enough had to do with security concerns raised by an infamous Russian hacker about the FSB’s own preferred method of being contacted.

KrebsOnSecurity was seeking comment from the FSB about a blog post published by Vladislav “BadB” Horohorin, a former international stolen credit card trafficker who served seven years in U.S. federal prison for his role in the theft of $9 million from RBS WorldPay in 2009. Horohorin, a citizen of Russia, Israel and Ukraine, is now back where he grew up in Ukraine, running a cybersecurity consulting business.

Horohorin’s BadB carding store, badb[.]biz, circa 2007. Image: Archive.org.

Visit the FSB’s website and you might notice its web address starts with http:// instead of https://, meaning the site is not using an encryption certificate. In practical terms, any information shared between the visitor and the website is sent in plain text and will be visible to anyone who has access to that traffic.

This appears to be the case regardless of which Russian government site you visit. According to Russian search giant Yandex, the laws of the Russian Federation demand that encrypted connections be installed according to the Russian GOST cryptographic algorithm.

That means those who have a reason to send encrypted communications to a Russian government organization — including ordinary things like making a payment for a government license or fine, or filing legal documents — need to first install CryptoPro, a Windows-only application that loads the GOST encryption libraries on a user’s computer.

But if you want to talk directly to the FSB over an encrypted connection, you can just install their own client, which bundles the CryptoPro code. Visit the FSB’s site and select the option to “transfer meaningful information to operational units,” and you’ll see a prompt to install a “random number generation” application that is needed before a specific contact form on the FSB’s website will load properly.

Mind you, I’m not suggesting anyone go do that: Horohorin pointed out that this random number generator was flagged by 20 different antivirus and security products as malicious.

“Think well before contacting the FSB for any questions or dealing with them, and if you nevertheless decide to do this, it is better to use a virtual machine,” Horohorin wrote. “And a spacesuit. And, preferably, while in another country.”

Antivirus product detections on the FSB’s VPN software. Image: VirusTotal.

It’s probably worth mentioning that the FSB is the same agency that’s been sanctioned for malicious cyber activity by the U.S. government on multiple occasions over the past five years. According to the most recent sanctions by the U.S. Treasury Department, the FSB is known for recruiting criminal hackers from underground forums and offering them legal cover for their actions.

“To bolster its malicious cyber operations, the FSB cultivates and co-opts criminal hackers, including the previously designated Evil Corp., enabling them to engage in disruptive ransomware attacks and phishing campaigns,” reads a Treasury assessment from April 2021.

While Horohorin seems convinced the FSB is disseminating malware, it is not unusual for a large number of security tools used by VirusTotal or other similar malware “sandbox” services to incorrectly flag safe files as bad or suspicious — an all-too-common condition known as a “false positive.”

Late last year I warned my followers on Twitter to put off installing updates for their Dell products until the company could explain why a bunch of its software drivers were being detected as malware by two dozen antivirus tools. Those all turned out to be false positives.

To really figure out what this FSB software was doing, I turned to Lance James, the founder of Unit221B, a New York City based cybersecurity firm. James said each download request generates a new executable program. That is because the uniqueness of the file itself is part of what makes the one-to-one encrypted connection possible. Continue reading →

Using Fake Reviews to Find Dangerous Extensions

May 29, 2021
39 Comments

Fake, positive reviews have infiltrated nearly every corner of life online these days, confusing consumers while offering an unwelcome advantage to fraudsters and sub-par products everywhere. Happily, identifying and tracking these fake reviewer accounts is often the easiest way to spot scams. Here’s the story of how bogus reviews on a counterfeit Microsoft Authenticator browser extension exposed dozens of other extensions that siphoned personal and financial data.

Comments on the fake Microsoft Authenticator browser extension show the reviews for these applications are either positive or very negative — basically calling it out as a scam. Image: chrome-stats.com.

After hearing from a reader about a phony Microsoft Authenticator extension that appeared on the Google Chrome Store, KrebsOnSecurity began looking at the profile of the account that created it. There were a total of five reviews on the extension before it was removed: Three Google users gave it one star, warning people to stay far away from it; but two of the reviewers awarded it between three and four stars.

“It’s great!,” the Google account Theresa Duncan enthused, improbably. “I’ve only had very occasional issues with it.”

“Very convenient and handing,” assessed Anna Jones, incomprehensibly.

Google’s Chrome Store said the email address tied to the account that published the knockoff Microsoft extension also was responsible for one called “iArtbook Digital Painting.” Before it was removed from the Chrome Store, iArtbook had garnered just 22 users and three reviews. As with the knockoff Microsoft extension, all three reviews were positive, and all were authored by accounts with first and last names, like Megan Vance, Olivia Knox, and Alison Graham.

Google’s Chrome Store doesn’t make it easy to search by reviewer. For that I turned to Hao Nguyen, the developer behind chrome-stats.com, which indexes and makes searchable a broad array of attributes about extensions available from Google.

Looking at the Google accounts that left positive reviews on both the now-defunct Microsoft Authenticator and iArtbook extensions, KrebsOnSecurity noticed that each left positive reviews on a handful of other extensions that have since been removed.

Reviews on the iArtbook extension were all from apparently fake Google accounts that each reviewed two other extensions, one of which was published by the same developer. This same pattern was observed across 45 now-defunct extensions.

Like an ever-expanding venn diagram, a review of the extensions commented on by each new fake reviewer found led to the discovery of even more phony reviewers and extensions. In total, roughly 24 hours worth of digging through chrome-stats.com unearthed more than 100 positive reviews on a network of patently fraudulent extensions.

Those reviews in turn lead to the relatively straightforward identification of:

-39 reviewers who were happy with extensions that spoofed major brands and requested financial data
-45 malicious extensions that collectively had close to 100,000 downloads
-25 developer accounts tied to multiple banned applications

The extensions spoofed a range of consumer brands, including Adobe, Amazon, Facebook, HBO, Microsoft, Roku and Verizon. Scouring the manifests for each of these other extensions in turn revealed that many of the same developers were tied to multiple apps being promoted by the same phony Google accounts.

Some of the fake extensions have only a handful of downloads, but most have hundreds or thousands. A fake Microsoft Teams extension attracted 16,200 downloads in the roughly two months it was available from the Google store. A counterfeit version of CapCut, a professional video editing software suite, claimed nearly 24,000 downloads over a similar time period.

More than 16,000 people downloaded a fake Microsoft Teams browser extension over the roughly two months it was available for download from the Google Chrome store.

Unlike malicious browser extensions that can turn your PC into a botnet or harvest your cookies, none of the extensions examined here request any special permissions from users. Once installed, however, they invariably prompt the user to provide personal and financial data — all the while pretending to be associated with major brand names. Continue reading →

Boss of ATM Skimming Syndicate Arrested in Mexico

May 28, 2021
22 Comments

Florian “The Shark” Tudor, the alleged ringleader of a prolific ATM skimming gang that siphoned hundreds of millions of dollars from bank accounts of tourists visiting Mexico over the last eight years, was arrested in Mexico City on Thursday in response to an extradition warrant from a Romanian court.

Florian Tudor, at a 2020 press conference in Mexico in which he asserted he was a legitimate businessman and not a mafia boss. Image: OCCRP.

Tudor, a native of Craiova, Romania, moved to Mexico to set up Top Life Servicios, an ATM servicing company which managed a fleet of relatively new ATMs based in Mexico branded as Intacash.

Intacash was the central focus of a three–part investigation KrebsOnSecurity published in September 2015. That series tracked the activities of a crime gang working with Intacash that was bribing and otherwise coercing ATM technicians to install sophisticated Bluetooth-based skimmers inside cash machines throughout popular tourist destinations in and around Mexico’s Yucatan Peninsula — including Cancun, Cozumel, Playa del Carmen and Tulum.

Follow-up reporting last year by the Organized Crime and Corruption Reporting Project (OCCRP) found Tudor and his associates compromised more than 100 ATMs across Mexico using skimmers that were able to remain in place undetected for years. The OCCRP, which dubbed Tudor’s group “The Riviera Maya Gang,” estimates the crime syndicate used cloned card data and stolen PINs to steal more than $1.2 billion from bank accounts of tourists visiting the region.

Last year, a Romanian court ordered Tudor’s capture following his conviction in absentia for attempted murder, blackmail and the creation of an organized crime network that specialized in human trafficking.

Mexican authorities have been examining bank accounts tied to Tudor and his companies, and investigators believe Tudor and his associates paid protection and hush money to various Mexican politicians and officials over the years. In February, the leader of Mexico’s Green Party stepped down after it emerged that he received funds from Tudor’s group.

This is the second time Mexican authorities have detained Tudor. In April 2019, Tudor and his deputy were arrested for illegal firearms possession. That arrest came just months after Tudor allegedly ordered the execution of a former bodyguard who was trying to help U.S. authorities bring down the group’s lucrative skimming operations.

Tudor’s arrest this week inside the premises of the Mexican Attorney General’s Office did not go smoothly, according to Mexican news outlets. El Universal reports that a brawl broke out between Tudor’s lawyers and officials at the Mexican AG’s office, and a video released by the news outlet on Twitter shows Tudor resisting arrest as he is being hauled out of the building hand and foot.

A Mexican judge will decide on Tudor’s extradition to Romania in the coming weeks.

How to Tell a Job Offer from an ID Theft Trap

May 21, 2021
57 Comments

One of the oldest scams around — the fake job interview that seeks only to harvest your personal and financial data — is on the rise, the FBI warns. Here’s the story of a recent LinkedIn impersonation scam that led to more than 100 people getting duped, and one almost-victim who decided the job offer was too-good-to-be-true.

Last week, someone began posting classified notices on LinkedIn for different design consulting jobs at Geosyntec Consultants, an environmental engineering firm based in the Washington, D.C. area. Those who responded were told their application for employment was being reviewed and that they should email Troy Gwin — Geosyntec’s senior recruiter — immediately to arrange a screening interview.

Gwin contacted KrebsOnSecurity after hearing from job seekers trying to verify the ad, which urged respondents to email Gwin at a Gmail address that was not his. Gwin said LinkedIn told him roughly 100 people applied before the phony ads were removed for abusing the company’s terms of service.

“The endgame was to offer a job based on successful completion of background check which obviously requires entering personal information,” Gwin said. “Almost 100 people applied. I feel horrible about this. These people were really excited about this ‘opportunity’.”

Erica Siegel was particularly excited about the possibility of working in a creative director role she interviewed for at the fake Geosyntec. Siegel said her specialty —  “consulting with start ups and small businesses to create sustainable fashion, home and accessories brands” — has been in low demand throughout the pandemic, so she’s applied to dozens of jobs and freelance gigs over the past few months.

On Monday, someone claiming to work with Gwin contacted Siegel and asked her to set up an online interview with Geosyntec. Siegel said the “recruiter” sent her a list of screening questions that all seemed relevant to the position being advertised.

Siegel said that within about an hour of submitting her answers, she received a reply saying the company’s board had unanimously approved her as a new hire, with an incredibly generous salary considering she had to do next to no work to get a job she could do from home.

Worried that her potential new dream job might be too-good-to-be-true, she sent the recruiter a list of her own questions that she had about the role and its position within the company.

But the recruiter completely ignored Siegel’s follow-up questions, instead sending a reply that urged her to get in touch with a contact in human resources to immediately begin the process of formalizing her employment. Which of course involves handing over one’s personal (driver’s license info) and financial details for direct deposit.

Multiple things about this job offer didn’t smell right to Siegel.

“I usually have six or seven interviews before getting a job,” Siegel said. “Hardly ever in my lifetime have I seen a role that flexible, completely remote and paid the kind of money I would ask for. You never get all three of those things.”

So she called her dad, an environmental attorney who happens to know and have worked with people at the real Geosyntec Consultants. Then she got in touch with the real Troy Gwin, who confirmed her suspicions that the whole thing was a scam.

“Even after the real Troy said they’d gotten these [LinkedIn] ads shut down, this guy was still emailing me asking for my HR information,” Siegel said. “So my dad said, ‘Troll him back, and tell him you want a signing bonus via money order.’ I was like, okay, what’s the worst that could happen? I never heard from him again.” Continue reading →

Recycle Your Phone, Sure, But Maybe Not Your Number

May 19, 2021
37 Comments

Many online services allow users to reset their passwords by clicking a link sent via SMS, and this unfortunately widespread practice has turned mobile phone numbers into de facto identity documents. Which means losing control over one thanks to a divorce, job termination or financial crisis can be devastating.

Even so, plenty of people willingly abandon a mobile number without considering the potential fallout to their digital identities when those digits invariably get reassigned to someone else. New research shows how fraudsters can abuse wireless provider websites to identify available, recycled mobile numbers that allow password resets at a range of email providers and financial services online.

Researchers in the computer science department at Princeton University say they sampled 259 phone numbers at two major wireless carriers, and found 171 of them were tied to existing accounts at popular websites, potentially allowing those accounts to be hijacked.

The Princeton team further found 100 of those 259 numbers were linked to leaked login credentials on the web, which could enable account hijackings that defeat SMS-based multi-factor authentication.

“Our key finding is that attackers can feasibly leverage number recycling to target previous owners and their accounts,” the researchers wrote. “The moderate to high hit rates of our testing methods indicate that most recycled numbers are vulnerable to these attacks. Furthermore, by focusing on blocks of Likely recycled numbers, an attacker can easily discover available recycled numbers, each of which then becomes a potential target.”

The researchers located newly-recycled mobile numbers by browsing numbers made available to customers interested in signing up for a prepaid account at T-Mobile or Verizon (apparently AT&T doesn’t provide a similar interface). They said they were able to identify and ignore large blocks of new, unused numbers, as these blocks tend to be made available consecutively — much like newly printed money is consecutively numbered in stacks.

The Princeton team has a number of recommendations for T-Mobile and Verizon, noting that both carriers allow unlimited inquiries on their prepaid customer platforms online — meaning there is nothing to stop attackers from automating this type of number reconnaissance.

“On postpaid interfaces, Verizon already has safeguards and T-Mobile does not even support changing numbers online,” the researchers wrote. “However, the number pool is shared between postpaid and prepaid, rendering all subscribers vulnerable to attacks.” Continue reading →

Try This One Weird Trick Russian Hackers Hate

May 17, 2021
147 Comments

In a Twitter discussion last week on ransomware attacks, KrebsOnSecurity noted that virtually all ransomware strains have a built-in failsafe designed to cover the backsides of the malware purveyors: They simply will not install on a Microsoft Windows computer that already has one of many types of virtual keyboards installed — such as Russian or Ukrainian. So many readers had questions in response to the tweet that I thought it was worth a blog post exploring this one weird cyber defense trick.

The Commonwealth of Independent States (CIS) more or less matches the exclusion list on an awful lot of malware coming out of Eastern Europe.

The Twitter thread came up in a discussion on the ransomware attack against Colonial Pipeline, which earlier this month shut down 5,500 miles of fuel pipe for nearly a week, causing fuel station supply shortages throughout the country and driving up prices. The FBI said the attack was the work of DarkSide, a new-ish ransomware-as-a-service offering that says it targets only large corporations.

DarkSide and other Russian-language affiliate moneymaking programs have long barred their criminal associates from installing malicious software on computers in a host of Eastern European countries, including Ukraine and Russia. This prohibition dates back to the earliest days of organized cybercrime, and it is intended to minimize scrutiny and interference from local authorities.

In Russia, for example, authorities there generally will not initiate a cybercrime investigation against one of their own unless a company or individual within the country’s borders files an official complaint as a victim. Ensuring that no affiliates can produce victims in their own countries is the easiest way for these criminals to stay off the radar of domestic law enforcement agencies.

Possibly feeling the heat from being referenced in President Biden’s Executive Order on cybersecurity this past week, the DarkSide group sought to distance itself from their attack against Colonial Pipeline. In a message posted to its victim shaming blog, DarkSide tried to say it was “apolitical” and that it didn’t wish to participate in geopolitics.

“Our goal is to make money, and not creating problems for society,” the DarkSide criminals wrote last week. “From today we introduce moderation and check each company that our partners want to encrypt to avoid social consequences in the future.”

But here’s the thing: Digital extortion gangs like DarkSide take great care to make their entire platforms geopolitical, because their malware is engineered to work only in certain parts of the world.

DarkSide, like a great many other malware strains, has a hard-coded do-not-install list of countries which are the principal members of the Commonwealth of Independent States (CIS) — former Soviet satellites that mostly have favorable relations with the Kremlin. The full exclusion list in DarkSide (published by Cybereason) is below:

Image: Cybereason.

Simply put, countless malware strains will check for the presence of one of these languages on the system, and if they’re detected the malware will exit and fail to install.

[Side note. Many security experts have pointed to connections between the DarkSide and REvil (a.k.a. “Sodinokibi”) ransomware groups. REvil was previously known as GandCrab, and one of the many things GandCrab had in common with REvil was that both programs barred affiliates from infecting victims in Syria. As we can see from the chart above, Syria is also exempted from infections by DarkSide ransomware. And DarkSide itself proved their connection to REvil this past week when it announced it was closing up shop after its servers and bitcoin funds were seized.] Continue reading →

DarkSide Ransomware Gang Quits After Servers, Bitcoin Stash Seized

May 14, 2021
210 Comments

The DarkSide ransomware affiliate program responsible for the six-day outage at Colonial Pipeline this week that led to fuel shortages and price spikes across the country is running for the hills. The crime gang announced it was closing up shop after its servers were seized and someone drained the cryptocurrency from an account the group uses to pay affiliates.

“Servers were seized (country not named), money of advertisers and founders was transferred to an unknown account,” reads a message from a cybercrime forum reposted to the Russian OSINT Telegram channel.

“A few hours ago, we lost access to the public part of our infrastructure,” the message continues, explaining the outage affected its victim shaming blog where stolen data is published from victims who refuse to pay a ransom.

“Hosting support, apart from information ‘at the request of law enforcement agencies,’ does not provide any other information,” the DarkSide admin says. “Also, a few hours after the withdrawal, funds from the payment server (ours and clients’) were withdrawn to an unknown address.”

DarkSide organizers also said they were releasing decryption tools for all of the companies that have been ransomed but which haven’t yet paid.

“After that, you will be free to communicate with them wherever you want in any way you want,” the instructions read. Continue reading →

Microsoft Patch Tuesday, May 2021 Edition

May 11, 2021
37 Comments

Microsoft today released fixes to plug at least 55 security holes in its Windows operating systems and other software. Four of these weaknesses can be exploited by malware and malcontents to seize complete, remote control over vulnerable systems without any help from users. On deck this month are patches to quash a wormable flaw, a creepy wireless bug, and yet another reason to call for the death of Microsoft’s Internet Explorer (IE) web browser.

While May brings about half the normal volume of updates from Microsoft, there are some notable weaknesses that deserve prompt attention, particularly from enterprises. By all accounts, the most pressing priority this month is CVE-2021-31166, a Windows 10 and Windows Server flaw which allows an unauthenticated attacker to remotely execute malicious code at the operating system level. With this weakness, an attacker could compromise a host simply by sending it a specially-crafted packet of data.

“That makes this bug wormable, with even Microsoft calling that out in their write-up,” said Dustin Childs, with Trend Micro’s ZDI program. “Before you pass this aside, Windows 10 can also be configured as a web server, so it is impacted as well. Definitely put this on the top of your test-and-deploy list.”

Kevin Breen from Immersive Labs said the fact that this one is just 0.2 points away from a perfect 10 CVSS score should be enough to identify just how important it is to patch.

“For ransomware operators, this kind of vulnerability is a prime target for exploitation,” Breen said. “Wormable exploits should always be a high priority, especially if they are for services that are designed to be public facing. As this specific exploit would not require any form of authentication, it’s even more appealing for attackers, and any organization using HTTP.sys protocol stack should prioritize this patch.”

Breen also called attention to CVE-2021-26419 — a vulnerability in Internet Explorer 11 — to make the case for why IE needs to stand for “Internet Exploder.” To trigger this vulnerability, a user would have to visit a site that is controlled by the attacker, although Microsoft also recognizes that it could be triggered by embedding ActiveX controls in Office Documents.

“IE needs to die – and I’m not the only one that thinks so,” Breen said. “If you are an organization that has to provide IE11 to support legacy applications, consider enforcing a policy on the users that restricts the domains that can be accessed by IE11 to only those legacy applications. All other web browsing should be performed with a supported browser.” Continue reading →