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Atomic macOS (AMOS) Stealer Activity

Unit 42 details an August 2026 AMOS macOS stealer infection delivered via fake 'macOS toolkit' pages and Terminal paste commands, exfiltrating credentials to C2.

Unit 42 analyzed an AMOS (Atomic macOS Stealer) infection from August 5, 2026, initiated via a page at getmacouscloud[.]com instructing users to paste a command into Terminal. The command fetched a Zsh script from ferncore13[.]com that delivered a Mach-O installer to /tmp/helper and supporting files under /Library/Application Support/.com.apple.accountsd/ and .com.apple.metadata.mds/. AMOS collected browser data, credentials, cryptocurrency wallets (Binance, TonKeeper), Telegram data, and FileGrabber content such as AWS and gcloud files, uploading it via HTTP POST to C2 server 161.35.146[.]120. AMOS has been advertised on Telegram since April 2024 and distributed via ClickFix campaigns, malicious ads, and cracked-software sites.

Palo Alto Unit 42 · 1d agoMalware in the wild

Hackers Use ClickFix Lures to Deploy MacSync Stealer and Bypass macOS Security.

ClickFix malvertising campaigns deliver MacSync, a macOS infostealer sold as MaaS that bypasses Gatekeeper via Terminal commands and steals credentials.

Threat actors use ClickFix social-engineering lures, SEO poisoning, and malvertising impersonating brands like Claude, ChatGPT, Zoom, and Docker to trick users into pasting curl-to-zsh commands into Terminal, evading Gatekeeper and notarization checks. The MacSync Stealer (formerly Mac.c, emerged April 2025, linked to developer 'Mentalpositive') is a 64-bit Mach-O stager with single-byte XOR string obfuscation that daemonizes, polls C2 with custom API-key headers, streams AppleScript payloads into osascript, and persists via fake LaunchAgents. It steals browser credentials, Keychain data, SSH keys, session tokens, and crypto wallets, exfiltrating archives in 10MB HTTP PUT chunks. Microsoft documented more than 30 related MacSync domains.

GBHackers · 7d agoMalware in the wild

Apple Xcode Integer Underflow Flaw Lets Crafted Archives Leak Memory and Crash Builds

Researchers disclosed an integer underflow in Apple's Mach-O archive parser that lets crafted static libraries crash Xcode builds or leak process memory.

SecureLayer7 disclosed an integer underflow in the mach_o::Archive::Entry::name() function in Apple's open-source dyld project, reported to Apple Product Security on May 23, 2026, with no public patch after more than 90 days. Crafted static archives (.a files) cause the parser's unsigned index to wrap to SIZE_MAX, producing SIGSEGV crashes in the ld-prime linker, out-of-bounds reads that may print adjacent memory to stderr, or SIGABRT in libtool and ranlib. The modern parser is used by ld-prime, the default linker for arm64, arm64e, and x86_64 since Xcode 15, while legacy ld-classic is unaffected. Crafted archives need only be processed, creating supply-chain risk via vendored SDKs, binary dependencies, and CI pipelines.

GBHackers · 6d agoVulnerability1

Fake OpenAI Codex download tricks macOS users into installing malware

Cato Networks uncovered a malware campaign using sponsored search ads and fake OpenAI Codex pages to deliver an AMOS-like infostealer to macOS users.

Cato Networks researchers discovered a campaign using sponsored search results and a fake OpenAI Codex download portal on Google Sites to lure macOS users. Victims are instructed to paste a Terminal command that decodes a Base64-encoded URL and runs a multi-stage infection chain ending in a universal Mach-O binary. The delivery chain closely resembles Atomic macOS Stealer (AMOS), and related infrastructure impersonating Claude Code was also found. Operators use iframe-based hosting and path/device gating to evade analysts and automated scanners.

Help Net Security · 23d agoMalware in the wild

Hackers Use Fake Claude and ChatGPT Installers to Infect Mac Users With Password-Stealing Malware

Attackers distribute MacSync macOS infostealer via fake Claude and ChatGPT installers and sponsored search ads, stealing passwords, cookies, keys, and wallets.

SEQRITE reports a malware-as-a-service campaign pushing MacSync, a macOS password stealer, through sponsored search results and fake Claude and ChatGPT download pages. ClickFix-style prompts trick users into pasting a Terminal command that launches a stager, which loads an in-memory AppleScript to harvest credentials. The malware collects browser vaults, Keychain data, SSH keys, session cookies, messaging sessions, and cryptocurrency wallets, then persists via renamed LaunchAgents and can request screen-recording permissions.

Cyber Security News · 7d agoMalware in the wild

AmnesiaStealer Hijacks Chromium Sessions to Give Attackers Live Browser Control on macOS

Jamf details AmnesiaStealer, a new Rust-based macOS infostealer that hijacks Chromium sessions for live attacker-controlled browser access and steals Keychain data.

Jamf Threat Labs disclosed a three-stage macOS infostealer called AmnesiaStealer distributed via a fake GitHub download page using a ClickFix-style lure that tricks users into pasting a Base64 command into Terminal. The Rust payload harvests the Keychain, Apple Notes, Telegram sessions, Safari cookies, and 16 Chromium-family browsers, and captures the system password via a native prompt validated with dscl. A remotely fetched stream_module gives operators hidden, interactive browser control via the Chrome DevTools Protocol, streaming a live session at roughly 3fps. It persists via a root LaunchDaemon impersonating Apple's crash reporter and leverages the TCC bypass CVE-2020-9771 against macOS Catalina.

The Hacker News · Aug 15, 2026Malware in the wildCVE-2020-9771