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
109 months ago
A malware discussion is political? Everyone should be able to comment on this.
Score: 19 Votes (Like | Disagree)
manu chao Avatar
109 months ago
Maybe it is time that MacKeeper is classified as malware by anti-malware applications ...
Score: 12 Votes (Like | Disagree)
keysofanxiety Avatar
109 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
109 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
109 months ago
Installation of that Mackeeper pest should be blocked on firmware level.
Score: 2 Votes (Like | Disagree)
997440 Avatar
109 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

apple wallet drivers license feature iPhone 15 pro

iPhone Driver's Licenses: These 17 U.S. States Offer Them or Will Later

Thursday June 19, 2025 11:28 am PDT by
In select U.S. states, residents can add their driver's license or state ID to the Wallet app on the iPhone and Apple Watch, providing a convenient and contactless way to display proof of identity or age at select airports and businesses, and in select apps. Unfortunately, this feature continues to roll out very slowly since it was announced in 2021, with only nine U.S. states and Puerto...
ios 26 call holding

iOS 26 Beta is Hiding a New Ringtone — Here's What It Sounds Like

Thursday June 19, 2025 7:25 pm PDT by
Apple is hiding a new ringtone within iOS 26. The new ringtone is an alternative version of the existing Reflection ringtone, which has been the default ringtone since the iPhone X was released in 2017. It was discovered within the code for the first developer beta of iOS 26, but it remains hidden, so you will not find it in the list of ringtones available in the Settings app for now. It...
iPhone 17 Pro Blue Feature Tighter Crop

iPhone 17 Pro Launching in Three Months With These 12 New Features

Saturday June 14, 2025 5:45 pm PDT by
The iPhone 17 Pro and iPhone 17 Pro Max are three months away, and there are plenty of rumors about the devices. Below, we recap key changes rumored for the iPhone 17 Pro models as of June 2025:Aluminum frame: iPhone 17 Pro models are rumored to have an aluminum frame, whereas the iPhone 15 Pro and iPhone 16 Pro models have a titanium frame, and the iPhone X through iPhone 14 Pro have a...
iPhone 16 Battery Life Feature

iOS 26's New Battery Life Mode Available Only on These iPhone Models

Saturday June 21, 2025 9:02 am PDT by
Last week, we reported that iOS 26 introduces an opt-in Adaptive Power Mode on the iPhone, alongside the existing Low Power Mode. Apple says that Adaptive Power Mode can make "small performance adjustments" when necessary to extend an iPhone's battery life, including slightly lowering the display brightness or allowing some activities to "take a little longer." The full description of...
apple watch ultra 2 new black

Apple Watch Ultra 3 Finally Coming After Two-Year Hiatus

Monday June 16, 2025 8:45 am PDT by
Apple will finally deliver the Apple Watch Ultra 3 sometime this year, according to analyst Jeff Pu of GF Securities Hong Kong (via @jukanlosreve). The analyst expects both the Apple Watch Series 11 and Apple Watch Ultra 3 to arrive this year (likely alongside the new iPhone 17 lineup, if previous launches are anything to go by), according to his latest product roadmap shared with...
iOS 18

Apple Releases iOS 18.6 Public Beta

Wednesday June 18, 2025 10:24 am PDT by
Apple today seeded the first betas of upcoming iOS 18.6 and iPadOS 18.6 updates to public beta testers, with the betas coming just a few days after Apple provided the betas to developers. Testers who have signed up for beta updates through Apple's beta site can download iOS 18.6 and iPadOS 18.6 from the Settings app on a compatible device by going to General > Software Update. When the...
General Spotify Feature

Spotify Preparing to Launch Long-Awaited Lossless Audio Tier on iPhone

Thursday June 19, 2025 1:46 pm PDT by
Spotify appears to be gearing up to launch its long-awaited lossless music tier. Chris Messina (via TechCrunch) and Spicetify (via The Verge) spotted new lossless references within the code for Spotify's desktop app and web player. With assistance from Aaron Perris, MacRumors has confirmed that the latest beta of the Spotify app for the iPhone also contains new lossless-related code....
Craig Federighi No

John Gruber Reacts to Apple Declining His Interview After His Criticism

Wednesday June 18, 2025 8:10 pm PDT by
Every year between 2015 and 2024, at least one Apple executive agreed to be interviewed by Daring Fireball's John Gruber for a special WWDC episode of his podcast, The Talk Show. Last year, for example, Apple's software engineering chief Craig Federighi, marketing chief Greg Joswiak, and top AI researcher John Giannandrea joined Gruber on stage at the California Theatre in San Jose to discuss...
airpods 4 blue

Apple Offering Free AirPods — Here's How to Get Them

Tuesday June 17, 2025 6:33 am PDT by
Apple is running a new promotion that offers free AirPods to qualifying customers. Now through September 30, college and university students in the U.S., Canada, Mexico, and Singapore can receive free AirPods 4 when they purchase an eligible new Mac or iPad from Apple. AirPods Pro 2 are also available at a discount. If you do not want AirPods, the promotion also offers various other...