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

Second Generation AirTag Feature

Apple Unveils New AirTag With Longer Range, Louder Speaker, and More

Monday January 26, 2026 6:07 am PST by
Apple today introduced the second-generation AirTag, with key features including longer range for tracking items and a louder speaker. For those who are not familiar, the AirTag is a small accessory that you can attach to your backpack, keys, or other items. Then, you can track the location of those items in the Find My app on the iPhone, iPad, Mac, Apple Watch, and iCloud.com. The new...
M5 MacBook Pro

Apple Reportedly Aiming to Upgrade the MacBook Pro Twice This Year

Sunday January 25, 2026 11:46 am PST by
Apple plans to release new MacBook Pro, MacBook Air, Mac Studio, and Studio Display models in the first half of this year, according to Bloomberg's Mark Gurman. In his Power On newsletter today, Gurman added that redesigned MacBook Pro models with an OLED touch screen "should be hitting toward the end of 2026," meaning that the MacBook Pro line would be upgraded twice this year. First up...
Apple Logo Spotlight

Apple to Launch These 20+ Products This Year

Sunday January 25, 2026 6:02 pm PST by
2026 promises to be yet another busy year for Apple, with the company rumored to be planning more than 20 product announcements over the coming months. Beyond the usual updates to iPhones, iPads, Macs, and Apple Watches, Apple is expected to release its all-new smart home hub, which was reportedly delayed until the more personalized version of Siri is ready. Other unique products rumored for ...
iOS 26

What to Expect From iOS 26.4

Friday January 23, 2026 12:31 pm PST by
iOS 26.3 is shaping up to be a relatively minor update, with only a couple of notable new features, but iOS 26.4 is expected to be much more significant. 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 few weeks away. Following beta testing, iOS 26.4 will likely be released to the general public at some point in March ...
top stories 2026 01 24

Top Stories: iPhone 18 Pro Leaks, Siri Chatbot, Apple AI Pin, and More

Saturday January 24, 2026 6:00 am PST by
Apple rumors are starting to pick up now that we're a few weeks into 2026, and this week saw some potential clarity around conflicting iPhone 18 Pro rumors, plus some new word on Apple's plans for Siri. This week also saw a report that Apple is working on some sort of AI pin while also making progress toward a major MacBook Pro revamp, so read on below for all the details! Top Stories iPh...