New 'Yontoo' Adware Trojan Targets Major Browsers on OS X

Russian security firm Doctor Web this week highlighted a new trojan (via The Next Web) affecting OS X systems and which installs an adware plug-in capable of injecting ads into users' browsing experience.

As with other trojans, this new Yontoo malware relies on tricking users into installing the package, which in this case masquerades as a movie trailer video plug-in, download accelerator, or other software a user might believe they want or need on their system.

When launched, Trojan.Yontoo.1 displays a dialogue window that asks the user if they want to install Free Twit Tube.

However, after the user presses ‘Continue’, instead of the promised program, the Trojan downloads (from the Internet) and installs the plugin Yontoo for Safari, Chrome and Firefox. These browsers are most popular among Mac OS X users. While a user surfs the web, the plugin transmits information about the loaded pages to a remote server.

In return, it gets a file that enables the Trojan to embed third-party code into pages visited by the user.

As an example of Yontoo's capabilities, Doctor Web shows how ads can be injected into apple.com once the plug-in has been unwittingly installed by the user.

apple_com_adware
Compared to Windows, OS X has long been a relatively unpopular target for malware authors, but attacks targeting Apple customers have been on the rise. Many of the most highly publicized attacks come via trojans that rely on tricking users into granting installation privileges, while third-party platforms such as Java have also frequently been used to inject code into Mac systems.

Apple has been increasing its efforts to fight malware, introducing a rudimentary anti-malware functionality in OS X Snow Leopard and an enhanced Gatekeeper system in OS X Mountain Lion. Apple has also increasingly been blocking vulnerable versions of Java until Oracle is able to release patched versions of its plug-ins.

Popular Stories

iPhone 15 Pro Cameras

iPhone 17 Pro Max Will Be First Model to Feature Three 48MP Cameras

Thursday July 11, 2024 12:20 am PDT by
Next year's iPhone 17 Pro Max will feature an upgraded 48-megapixel Tetraprism camera for enhanced photo quality and zoom functionality, according to Apple analyst Ming-Chi Kuo. In his n-iphone-tetraprism-upgrade-ca62dd37e364">latest investor note published to Medium, Kuo said the key specification change would be a 1/2.6" 48MP CIS sensor, up from the 1/3.1" 12MP sensor expected to be used...
Beyond iPhone 13 Better Blue Face ID Single Camera Hole

10 Reasons to Wait for Next Year's iPhone 17

Monday July 8, 2024 5:00 am PDT by
Apple's iPhone development roadmap runs several years into the future and the company is continually working with suppliers on several successive iPhone models simultaneously, which is why we sometimes get rumored feature leaks so far ahead of launch. The iPhone 17 series is no different – already we have some idea of what to expect from Apple's 2025 smartphone lineup. If you plan to skip...
maxresdefault

Apple's AirPods Pro 2 vs. Samsung's Galaxy Buds3 Pro

Saturday July 13, 2024 8:00 am PDT by
Samsung this week introduced its latest earbuds, the Galaxy Buds3 Pro, which look quite a bit like Apple's AirPods Pro 2. Given the similarities, we thought we'd compare Samsung's new earbuds to the AirPods Pro. Subscribe to the MacRumors YouTube channel for more videos. Design wise, you could potentially mistake Samsung's Galaxy Buds3 Pro for the AirPods Pro. The Buds3 Pro have the same...
primeday2020 feature3

The Best Early Prime Day Deals on Apple Products

Saturday July 13, 2024 6:23 am PDT by
Amazon is soon to be back with its annual summertime Prime Day event, lasting for just two days from July 16-17. As it does every year, Prime Day offers shoppers a huge selection of deals across Amazon's storefront, and there are already many deals you can get on sale ahead of the event. Note: MacRumors is an affiliate partner with Amazon. When you click a link and make a purchase, we may...
iPhone 16 Pro Sizes Feature

iPhone 16 Series Is Just Two Months Away: Everything We Know

Monday July 15, 2024 4:44 am PDT by
Apple typically releases its new iPhone series around mid-September, which means we are about two months out from the launch of the iPhone 16. Like the iPhone 15 series, this year's lineup is expected to stick with four models – iPhone 16, iPhone 16 Plus, iPhone 16 Pro, and iPhone 16 Pro Max – although there are plenty of design differences and new features to take into account. To bring ...

Top Rated Comments

Slix Avatar
148 months ago
Want to install Free Twit Tube?

Seems legit. :rolleyes:
Score: 20 Votes (Like | Disagree)
litmag01 Avatar
148 months ago
Say YES to everything unless it asks to continue.

In that case, press CONTINUE and enter bank account number, routing number and any pertinant passwords.
Score: 18 Votes (Like | Disagree)
anzio Avatar
148 months ago
It's times like this that I'm glad that OS X has XProtect.

Oh yeah. And I'm happy I also wield common sense. :)
Score: 14 Votes (Like | Disagree)
Pechente Avatar
148 months ago
Wow, a user can be tricked to actively install harmful software - a serious flaw in OS X!
Score: 11 Votes (Like | Disagree)
Apple_Robert Avatar
148 months ago
Macs were never as secure as PCs but they were unpopular enough that nobody bothered to attempt to exploit them. Now it seems that every other day there's another massive security flaw found in Mac OS X.

What security flaw are you referring to with this story?
Score: 9 Votes (Like | Disagree)
vmistery Avatar
148 months ago
Macs were never as secure as PCs but they were unpopular enough that nobody bothered to attempt to exploit them. Now it seems that every other day there's another massive security flaw found in Mac OS X.

You missed patch Tuesday then?
Score: 9 Votes (Like | Disagree)