A new information-stealing malware has set its sights on Apple's macOS operating system to siphon sensitive information from compromised devices.
Dubbed MacStealer, it's the latest example of a threat that uses Telegram as a command-and-control (C2) platform to exfiltrate data. It primarily affects devices running macOS versions Catalina and later running on M1 and M2 CPUs.
"MacStealer has the ability to steal documents, cookies from the victim's browser, and login information," Uptycs researchers Shilpesh Trivedi and Pratik Jeware said in a new report.
First advertised on online hacking forums for $100 at the start of the month, it is still a work in progress, with the malware authors planning to add features to capture data from Apple's Safari browser and the Notes app.
In its current form, MacStealer is designed to extract iCloud Keychain data, passwords and credit card information from browsers like Google Chrome, Mozilla Firefox, and Brave. It also features support for harvesting Microsoft Office files, images, archives, and Python scripts.
The exact method used to deliver the malware is not known, but it is propagated as a DMG file (weed.dmg) that, when executed, opens a fake password prompt to harvest the passwords under the guise of seeking access to the System Settings app.
MacStealer is one of several info-stealers that have surfaced just over the past few months and adds to an already large number of similar tools currently in the wild.
This also includes another piece of new C#-based malware called HookSpoofer that's inspired by StormKitty and comes with keylogging and clipper abilities and transmits the stolen data to a Telegram bot.
Another browser cookie-stealing malware of note is Ducktail, which also uses a Telegram bot to exfiltrate data and re-emerged in mid-February 2023 with improved tactics to sidestep detection.
This involves "changing the initial infection from an archive containing a malicious executable to an archive containing a malicious LNK file that would start the infection chain," Deep Instinct researcher Simon Kenin said earlier this month.
Stealer malware is typically spread through different channels, including email attachments, bogus software downloads, and other social engineering techniques.
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To mitigate such threats, it's recommended that users keep their operating system and security software up to date and avoid downloading files or clicking links from unknown sources.
"As Macs have become increasingly popular in the enterprise among leadership and development teams, the more important the data stored on them is to attackers," SentinelOne researcher Phil Stokes said last week.
MacStealer's Source Code Gets Leaked
Cybersecurity firm Trend Micro, in an independent technical report published on March 30, disclosed that the malware's source code has been leaked via an online public scanning service.
"The malware is currently spreading via third party websites using images and graphics ripped off from real P2E [play-to-earn] applications, and promoted on social media and messaging platforms Twitter, Discord, and Telegram," researchers Qi Sun and Luis Magisa said.
"The threat actors behind the malware pose as a legitimate game company looking for testers and enticing potential victims to download their app. They post fake job vacancies and entice job hunters to download their malware binary."
MacStealer, besides siphoning browser and iCloud Keychain information, features capabilities to steal data from cryptocurrency wallets such as Binance, Exodus, Keplr, MetaMask, Phantom, and Trust Wallet and empty them.
"It uses chainbreaker to dump the keychain," the researchers explained. "It pops a dialog box to defraud the user's password using osascript."
Trend Micro further said the cybercriminals behind the social engineering campaign abused Twitter's new paid verification requirements to obtain a blue Verified badge, providing an "illusion of legitimacy" to distribute the rogue apps.