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Published by CyberDudeBivash Pvt Ltd · macOS Forensic Research & Defensive Engineering Unit

Critical Malware Alert · macOS Infiltration · MacSync Stealer · Crypto Exfiltration

Inside MacSync: The Stealthy Variant Hunting for Your Crypto Keys and Browser Cookies While You Sleep.

By CyberDudeBivash

Founder, CyberDudeBivash Pvt Ltd · Senior macOS Forensic Architect

The Intelligence Reality: The myth of the “Impenetrable Mac” has officially collapsed. In the final weeks of 2025, a highly sophisticated variant of the MacSync (formerly Mac.c) stealer has unmasked a fatal flaw in Apple’s trust-based security model. By utilizing stolen or fraudulent Apple Developer Certificates, MacSync bypasses Gatekeeper and XProtect to silently siphon iCloud Keychains, browser cookies, and hardware crypto-wallet secrets.

In this CyberDudeBivash Tactical Deep-Dive, we unmask the mechanics of the MacSync 2025 variant. We analyze the Swift-based dropper, the AppleScript obfuscation, and the Shadow-Persistence mechanism that allows it to remain dormant until your device enters Power Nap. If you are an executive or developer on macOS, your digital identity is the primary target.

Tactical Intelligence Index:

1. The ‘Trusted App’ Infection Vector: Bypassing Gatekeeper

The brilliance of MacSync lies in its deceptive provenance. Unlike older stealers that required users to run terminal commands, the 2025 variant is distributed as a Signed and Notarized Swift Application. Masquerading as a chat messenger installer (e.g., zk-call-messenger-installer.dmg), it carries a valid Apple Developer ID (Team ID: GNJLS3UYZ4).

Once downloaded, the disk image (DMG) is inflated to ~25MB using decoy PDF documents to evade simple cloud scanners. When the app is launched, it performs a connectivity check and ensures it hasn’t run within the last hour. If it detects a sandbox or a fresh execution, it stays dormant, silently waiting for the user to be inactive.

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2. Forensic Analysis: The Keychain & Cookie Harvest

Once active, MacSync utilizes a series of AppleScript commands piped directly into osascript to evade detection by standard command-line monitoring. It targets three primary digital goldmines:

iCloud Keychain: It triggers a fake system prompt asking for the user’s password. Once provided, it dumps the login.keychain-db file.
Browser Cookies: It specifically scans for Chrome, Brave, and Edge session cookies. This allows attackers to bypass MFA on sensitive accounts through session hijacking.
Messaging Logs: It targets Telegram Desktop and Signal databases to harvest sensitive internal corporate communications.

[Image showing the exfiltration path from the macOS File System to an attacker-controlled C2 server via HTTPS]

3. Ledger & Trezor Suite Phishing: The High-Value Target

MacSync includes a unique module for Hardware Wallet Phishing. It checks for the installation of Ledger Live or Trezor Suite. If found, the malware downloads a “Replacement” binary that looks identical to the official app. When the user attempts to sign a transaction, the fake app prompts for the recovery seed phrase, which is instantly exfiltrated over HTTP.

5. The CyberDudeBivash macOS Mandate

We do not suggest security; we mandate it. To prevent MacSync from compromising your digital life, every Apple user must implement these four pillars of integrity:

I. Strict App Notarization Audit

Go to **System Settings > Privacy & Security**. Ensure “Allow applications from” is set to “App Store” only. Manually whitelist essential tools using MDM.

II. TCC Permission Hardening

Regularly audit **Transparency, Consent, and Control (TCC)** settings. Deny “Full Disk Access” to any application that does not strictly require it for core functionality.

III. Phish-Proof FIDO2 Identity

Browser cookies are the new perimeter. Mandate FIDO2 Hardware Keys from AliExpress for all critical logins to stop session-theft bypasses.

IV. Behavioral macOS EDR

Deploy **Kaspersky Hybrid Cloud Security**. Monitor for anomalous `osascript` or `curl` commands spawning from signed, third-party apps.

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6. Automated Forensic Audit Script

To verify if your Mac has been hit by the MacSync variant, execute this Terminal script to check for common persistence logs and temp artifacts:

 #!/bin/bash

CyberDudeBivash MacSync Forensic Scanner
echo "[] Checking for MacSync log artifacts..." if [ -f ~/Library/Logs/UserSyncWorker.log ]; then echo "[!] CRITICAL: MacSync Log Found! Investigation Required." fi echo "[] Checking for anomalous scripts in /tmp..." ls /tmp | grep -E ".scpt|runner" echo "[*] Verifying Developer Certificate Revocations..." spctl --assess --verbose /Applications/zk-call.app 2>&1 | grep "revoked"

Expert FAQ: MacSync Infiltration

Q: If the app is signed by Apple, isn’t it safe?

A: No. Attackers use stolen identities to register for the Developer Program or buy accounts on the darknet. **Notarization** only means the app has been scanned for known malware *at that moment*. It does not prevent “Staged Malignancy” where the app downloads its payload later.

Q: Can I get my crypto back if my seed phrase was stolen?

A: No. Once a seed phrase is exfiltrated, the wallet is compromised forever. If you suspect an infection, immediately transfer all assets to a fresh hardware wallet with a new seed phrase generated on an air-gapped device.

GLOBAL SECURITY TAGS:#CyberDudeBivash#ThreatWire#MacSync#macOSSecurity#KeychainTheft#CryptoDrainer#ZeroTrust#CybersecurityExpert#InfoSecGlobal#EndpointDefense

Your Trust is Their Lever. Harden it.

MacSync is a reminder that the hardware layer is only as secure as the human layer. If your organization relies on Macs and you haven’t performed a forensic certificate audit in the last 72 hours, you are at risk. Reach out to CyberDudeBivash Pvt Ltd for an elite-level macOS security sweep and workstation hardening today.

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