Threats Tagged 'macsync'

MacSync Stealer is a macOS-targeting malware that exfiltrates credentials, browser data, and cryptocurrency wallets. It uses a Stage 2 zsh loader with a static API key observed across multiple command-and-control (C2) domains, indicating parallel infrastructure operation. The malware transmits victim account passwords in cleartext via URL query strings, exposing sensitive information in web proxy logs. Recent activity includes rapid rotation and deployment of new C2 domains shortly after public disclosures, complicating detection and blocking efforts.

A sophisticated macOS malware campaign leverages ClickFix social engineering to infect victims. The attack begins with a fake CAPTCHA prompt delivered via email links, tricking users into executing malicious commands in Terminal. This downloads a profiling script that collects system information and deploys architecture-specific Go-based Mach-O payloads. The stealer targets browser passwords, Apple Keychain credentials, and cryptocurrency wallets. Its most notable feature is a DRAIN function that gradually siphons cryptocurrency from victims' wallets by redirecting portions to attacker-controlled accounts. The malware supports Bitcoin, Litecoin, Dogecoin, Monero, Ethereum, and XRP. Infrastructure analysis reveals hosting through Aeza Group, a sanctioned Russian bulletproof hosting provider. The malware achieves persistence through macOS Background Task Management and uses various evasion techniques including Gatekeeper bypass and credential harvesting via fake system prompts.

In this article Activity overview How ClickFix works Campaign overview ClickFix moved from open pages to fingerprinting gates The fingerprinting gate Mitigation and protection guidance Indicators of compromise (IOC) References Learn more Microsoft Threat Intelligence observed a macOS ClickFix campaign distributing infostealers, including MacSync and Atomic Stealer (AMOS) , through a large cluster of look-alike domains. The campaign evolved from broadly serving ClickFix lures to using a server-side browser-fingerprinting gate that shows the lure primarily to visitors whose environment appears consistent with a genuine macOS browser. This cloaking limits visibility for crawlers, sandboxes, and some automated analysis workflows. The blog details the domain pattern, fingerprinting checks, infection chain, detection coverage, and hunting pivots that defenders can use to identify related activity. Activity overview Microsoft Threat Intelligence has been tracking a macOS ClickFix operation that distributes information-stealing malware through a large family of algorithmically named domains. Over several weeks of monitoring, Microsoft observed a notable shift in tradecraft: the same infrastructure moved from openly serving the malicious command in the served page’s HTML source to concealing the lure behind a server-side fingerprinting gate that reveals the payload only to visitors the server assesses as a genuine macOS target. The chain ultimately delivers information stealers such as MacSync or Atomic Stealer (AMOS). This activity is consistent with the broader shift in macOS ClickFix tradecraft that Microsoft Threat Intelligence previously documented , in which threat actors instruct users to run Terminal commands that retrieve remotely hosted content rather than the traditional approach of delivering a disk image for manual installation. The cluster described here is notable for two reasons: its domains are mass-produced by a recognizable name generator, and it adopted server-side cloaking on existing infrastructure, giving defenders a clear before-and-after view of the same operation. In this blog, we describe the campaign’s domain-generation pattern, the two delivery phases we observed, the fingerprinting gate that now fronts the infrastructure, and the end-to-end infection chain. We also provide hunting guidance, mitigation recommendations, and defanged indicators of compromise. How ClickFix works ClickFix is a social-engineering technique where attackers persuade users to copy and run a command in Terminal instead of downloading a traditional macOS application. The lure usually appears as a fake verification step, software update, download error, or CAPTCHA, with the command disguised as something required to complete the action. Because execution starts from a user-run Terminal command rather than a downloaded app bundle, the flow can avoid parts of the normal macOS application trust path, including quarantine handling, code-signing evaluation, and notarization checks typically applied to downloaded applications. In this campaign, ClickFix remains the delivery mechanism, but the important change is that the lure is no longer shown to every visitor. The page first profiles the visitor through a browser-fingerprinting gate and primarily requests consistent with a genuine macOS browser environment receive the fake “Download for macOS” page and copied Terminal command. Figure 1a – The counterfeit “Download for macOS” page served to a qualifying visitor by a cloaked gate (apricotfilepoint[.]com). The page displays a forged “Verified Publisher” badge and offers a one-click Copy of an obfuscated curl one-liner. Delivery is conditional. During analysis, the same URLs returned different content to different requests. In some case the macOS ClickFix lure, and in others an apparently benign decoy page. In our testing, a request presenting a Windows browser received a decoy page such as a fake browser-extension or VPN landing page (Figure…