A new version of Xagent, malware reportedly created by Russian hacking group APT28, has been discovered, and this version targets Mac users.

As outlined in a blog post by antivirus company Bitdefender (via Ars Technica), Xagent has previously been used to infiltrate Windows, iOS, Android, and Linux devices, but now Macs are vulnerable to attack as well. This is the first version of Xagent that's believed to be able to infiltrate Macs.

macbook pros 2015
The Mac version of Xagent is described as a backdoor that can be customized to do things like log passwords, detect system configurations, execute files, take screenshots of the display, and access iOS backups stored on the Mac.

The sample we are discussing today has been linked to the Mac OSX version of Xagent component from Sofacy/APT28/Sednit APT. This modular backdoor with advanced cyber-espionage capabilities is most likely planted on the system via the Komplex downloader.

Once successfully installed, the backdoor checks if a debugger is attached to the process. If it detects one, it terminates itself to prevent execution. Otherwise, it waits for an Internet connection before initiating communication with the C&C servers.

After the communication has been established, the payload starts the modules. Our preliminary analysis shows most of the C&C URLs impersonate Apple domains.

APT28 is the cyberespionage group that has been accused of hacking into the U.S. Democratic National Committee last year and interfering with the 2016 presidential election.

Bitdefender isn't entirely sure how the Mac version of Xagent is being distributed to users, but it could be spread via a macOS malware downloader called Komplex, which exploits a vulnerability in the virus-like MacKeeper software. Research on the malware is ongoing.

Mac users concerned about Xagent should avoid downloading anything that doesn't come from the Mac App Store or a well-known developer.

Note: Due to the political nature of the discussion regarding this topic, the discussion thread is located in our Politics, Religion, Social Issues forum. All forum members and site visitors are welcome to read and follow the thread, but posting is limited to forum members with at least 100 posts.

Top Rated Comments

bluespark Avatar
117 months ago
A malware discussion is political? Everyone should be able to comment on this.
Score: 19 Votes (Like | Disagree)
manu chao Avatar
117 months ago
Maybe it is time that MacKeeper is classified as malware by anti-malware applications ...
Score: 12 Votes (Like | Disagree)
keysofanxiety Avatar
117 months ago
Maybe it is time that MacKeeper is classified as malware by anti-malware applications ...
It is. MalwareBytes deletes it.
Score: 5 Votes (Like | Disagree)
John.B Avatar
117 months ago
Mac users concerned about Xagent should avoid downloading anything that doesn't come from the Mac App Store or a well-known developer.
The attack vector is based on a vulnerability in Mackeeper.

Keep that off your Mac and you'll be fine.
Score: 5 Votes (Like | Disagree)
Kajje Avatar
117 months ago
Installation of that Mackeeper pest should be blocked on firmware level.
Score: 2 Votes (Like | Disagree)
997440 Avatar
117 months ago
More information on this issue from @thomasareed. He's unable to post here because he has less than 100 posts.

He wanted to let us "know that this new "XAgent" variant of Komplex has absolutely no relation to a MacKeeper exploit. The writer has conflated this variant with one specific older variant from 2015. As much as I'd like to be able to blame MacKeeper, that vulnerability was closed in 2015, and there's no indication whatsoever that MacKeeper is in any way involved with the "XAgent" variant."





(Mr. Reed works for Malwarebytes and codes Malwarebytes Anti-Malware for Mac. Prior to this he developed Adware Medic and wrote extensively about security matters, and other Mac matters, at thesafemac((dot))com.)
Score: 2 Votes (Like | Disagree)

Popular Stories

iOS 26

iOS 26.3 and iOS 26.4 Will Add These New Features to Your iPhone

Tuesday February 3, 2026 7:47 am PST by
We are still waiting for the iOS 26.3 Release Candidate to come out, so the first iOS 26.4 beta is likely still at least a week or two away. Following beta testing, iOS 26.4 will likely be released to the general public in March or April. Below, we have recapped known or rumored iOS 26.3 and iOS 26.4 features so far. iOS 26.3 iPhone to Android Transfer Tool iOS 26.3 makes it easier...
Apple Logo Black

Apple's Next Launch is 'Imminent'

Sunday February 1, 2026 12:31 pm PST by
The calendar has turned to February, and a new report indicates that Apple's next product launch is "imminent," in the form of new MacBook Pro models. "All signs point to an imminent launch of next-generation MacBook Pros that retain the current form factor but deliver faster chips," Bloomberg's Mark Gurman said on Sunday. "I'm told the new models — code-named J714 and J716 — are slated...
iOS 26 Home Feature

Apple Gives Final Warning to Home App Users

Tuesday February 3, 2026 8:55 am PST by
In 2022, Apple introduced a new Apple Home architecture that is "more reliable and efficient," and the deadline to upgrade and avoid issues is fast approaching. In an email this week, Apple gave customers a final reminder to upgrade their Home app by February 10, 2026. Apple says users who do not upgrade may experience issues with accessories and automations, or lose access to their smart...
Aston Martin CarPlay Ultra Screen

Apple's CarPlay Ultra to Expand to These Vehicle Brands Later This Year

Sunday February 1, 2026 10:08 am PST by
Last year, Apple launched CarPlay Ultra, the long-awaited next-generation version of its CarPlay software system for vehicles. Nearly nine months later, CarPlay Ultra is still limited to Aston Martin's latest luxury vehicles, but that should change fairly soon. In May 2025, Apple said many other vehicle brands planned to offer CarPlay Ultra, including Hyundai, Kia, and Genesis. In his Powe...
Apple Foldable Thumb

First Foldable iPhone Design Details Revealed

Monday February 2, 2026 7:19 am PST by
Apple's first foldable iPhone will feature relocated volume buttons, an all-black camera plateau, a smaller Dynamic Island, and more, according to design leaks from a known Weibo leaker. The user known as "Instant Digital" today claimed to share several key details about the design of the foldable iPhone: The volume buttons will be located on the top edge of the device, aligned to the...