McAfee

Be Very Sparing in Allowing Site Notifications

An increasing number of websites are asking visitors to approve “notifications,” browser modifications that periodically display messages on the user’s mobile or desktop device. In many cases these notifications are benign, but several dodgy firms are paying site owners to install their notification scripts and then selling that communications pathway to scammers and online hucksters.

Notification prompts in Firefox (left) and Google Chrome.

When a website you visit asks permission to send notifications and you approve the request, the resulting messages that pop up appear outside of the browser. For example, on Microsoft Windows systems they typically show up in the bottom right corner of the screen — just above the system clock. These so-called “push notifications” rely on an Internet standard designed to work similarly across different operating systems and web browsers.

But many users may not fully grasp what they are consenting to when they approve notifications, or how to tell the difference between a notification sent by a website and one made to appear like an alert from the operating system or another program that’s already installed on the device.

This is evident by the apparent scale of the infrastructure behind a relatively new company based in Montenegro called PushWelcome, which advertises the ability for site owners to monetize traffic from their visitors. The company’s site currently is ranked by Alexa.com as among the top 2,000 sites in terms of Internet traffic globally.

Website publishers who sign up with PushWelcome are asked to include a small script on their page which prompts visitors to approve notifications. In many cases, the notification approval requests themselves are deceptive — disguised as prompts to click “OK” to view video material, or as “CAPTCHA” requests designed to distinguish automated bot traffic from real visitors.

An ad from PushWelcome touting the money that websites can make for embedding their dodgy push notifications scripts.

Approving notifications from a site that uses PushWelcome allows any of the company’s advertising partners to display whatever messages they choose, whenever they wish to, and in real-time. And almost invariably, those messages include misleading notifications about security risks on the user’s system, prompts to install other software, ads for dating sites, erectile disfunction medications, and dubious investment opportunities.

That’s according to a deep analysis of the PushWelcome network compiled by Indelible LLC, a cybersecurity firm based in Portland, Ore. Frank Angiolelli, vice president of security at Indelible, said rogue notifications can be abused for credential phishing, as well as foisting malware and other unwanted applications on users.

“This method is currently being used to deliver something akin to adware or click fraud type activity,” Angiolelli said. “The concerning aspect of this is that it is so very undetected by endpoint security programs, and there is a real risk this activity can be used for much more nefarious purposes.”

Sites affiliated with PushWelcome often use misleading messaging to trick people into approving notifications.

Angiolelli said the external Internet addresses, browser user agents and other telemetry tied to people who’ve accepted notifications is known to PushWelcome, which could give them the ability to target individual organizations and users with any number of fake system prompts.

Indelible also found browser modifications enabled by PushWelcome are poorly detected by antivirus and security products, although he noted Malwarebytes reliably flags as dangerous publisher sites that are associated with the notifications.

Indeed, Malwarebytes’ Pieter Arntz warned about malicious browser push notifications in a January 2019 blog post. That post includes detailed instructions on how to tell which sites you’ve allowed to send notifications, and how to remove them.

KrebsOnSecurity installed PushWelcome’s notifications on a brand new Windows test machine, and found that very soon after the system was peppered with alerts about malware threats supposedly found on the system. One notification was an ad for Norton antivirus; the other was for McAfee. Clicking either ultimately led to “buy now” pages at either Norton.com or McAfee.com.

Clicking on the PushWelcome notification in the bottom right corner of the screen opened a Web site claiming my brand new test system was infected with 5 viruses.

It seems likely that PushWelcome and/or some of its advertisers are trying to generate commissions for referring customers to purchase antivirus products at these companies. McAfee has not yet responded to requests for comment. Norton issued the following statement:

“We do not believe this actor to be an affiliate of NortonLifeLock. We are continuing to investigate this matter. NortonLifeLock takes affiliate fraud and abuse seriously and monitors ongoing compliance. When an affiliate partner abuses its responsibilities and violates our agreements, we take necessary action to remove these affiliate partners from the program and swiftly terminate our relationships. Additionally, any potential commissions earned as a result of abuse are not paid. Furthermore, NortonLifeLock sends notification to all of our affiliate partner networks about the affiliate’s abuse to ensure the affiliate is not eligible to participate in any NortonLifeLock programs in the future.”

Requests for comment sent to PushWelcome via email were returned as undeliverable. Requests submitted through the contact form on the company’s website also failed to send.

While scammy notifications may not be the most urgent threat facing Internet users today, most people are probably unaware of how this communications pathway can be abused.

What’s more, dodgy notification networks could be used for less conspicuous and sneakier purposes, including spreading fake news and malware masquerading as update notices from the user’s operating system. I hope it’s clear that regardless of which browser, device or operating system you use, it’s a good idea to be judicious about which sites you allow to serve notifications.

If you’d like to prevent sites from ever presenting notification requests, check out this guide, which has instructions for disabling notification prompts in Chrome, Firefox and Safari. Doing this for any devices you manage on behalf of friends, colleagues or family members might end up saving everyone a lot of headache down the road.

Microsoft Patch Tuesday, October 2020 Edition

It’s Cybersecurity Awareness Month! In keeping with that theme, if you (ab)use Microsoft Windows computers you should be aware the company shipped a bevy of software updates today to fix at least 87 security problems in Windows and programs that run on top of the operating system. That means it’s once again time to backup and patch up.

Eleven of the vulnerabilities earned Microsoft’s most-dire “critical” rating, which means bad guys or malware could use them to gain complete control over an unpatched system with little or no help from users.

Worst in terms of outright scariness is probably CVE-2020-16898, which is a nasty bug in Windows 10 and Windows Server 2019 that could be abused to install malware just by sending a malformed packet of data at a vulnerable system. CVE-2020-16898 earned a CVSS Score of 9.8 (10 is the most awful).

Security vendor McAfee has dubbed the flaw “Bad Neighbor,” and in a blog post about it said a proof-of-concept exploit shared by Microsoft with its partners appears to be “both extremely simple and perfectly reliable,” noting that this sucker is imminently “wormable” — i.e. capable of being weaponized into a threat that spreads very quickly within networks.

“It results in an immediate BSOD (Blue Screen of Death), but more so, indicates the likelihood of exploitation for those who can manage to bypass Windows 10 and Windows Server 2019 mitigations,” McAfee’s Steve Povolny wrote. “The effects of an exploit that would grant remote code execution would be widespread and highly impactful, as this type of bug could be made wormable.”

Trend Micro’s Zero Day Initiative (ZDI) calls special attention to another critical bug quashed in this month’s patch batch: CVE-2020-16947, which is a problem with Microsoft Outlook that could result in malware being loaded onto a system just by previewing a malicious email in Outlook.

“The Preview Pane is an attack vector here, so you don’t even need to open the mail to be impacted,” said ZDI’s Dustin Childs.

While there don’t appear to be any zero-day flaws in October’s release from Microsoft, Todd Schell from Ivanti points out that a half-dozen of these flaws were publicly disclosed prior to today, meaning bad guys have had a jump start on being able to research and engineer working exploits.

Other patches released today tackle problems in Exchange Server, Visual Studio, .NET Framework, and a whole mess of other core Windows components.

For any of you who’ve been pining for a Flash Player patch from Adobe, your days of waiting are over. After several months of depriving us of Flash fixes, Adobe’s shipped an update that fixes a single — albeit critical — flaw in the program that crooks could use to install bad stuff on your computer just by getting you to visit a hacked or malicious website.

Chrome and Firefox both now disable Flash by default, and Chrome and IE/Edge auto-update the program when new security updates are available. Mercifully, Adobe is slated to retire Flash Player later this year, and Microsoft has said it plans to ship updates at the end of the year that will remove Flash from Windows machines.

It’s a good idea for Windows users to get in the habit of updating at least once a month, but for regular users (read: not enterprises) it’s usually safe to wait a few days until after the patches are released, so that Microsoft has time to iron out any chinks in the new armor.

But before you update, please make sure you have backed up your system and/or important files. It’s not uncommon for a Windows update package to hose one’s system or prevent it from booting properly, and some updates even have known to erase or corrupt files.

So do yourself a favor and backup before installing any patches. Windows 10 even has some built-in tools to help you do that, either on a per-file/folder basis or by making a complete and bootable copy of your hard drive all at once.

And if you wish to ensure Windows has been set to pause updating so you can back up your files and/or system before the operating system decides to reboot and install patches on its own schedule, see this guide.

As always, if you experience glitches or problems installing any of these patches this month, please consider leaving a comment about it below; there’s a better-than-even chance other readers have experienced the same and may chime in here with some helpful tips.