New MacSync macOS Stealer Uses Signed App to Bypass Apple Gatekeeper
Source Reddit InfoSec News
Description
MacSync is a newly identified macOS stealer malware that uses a signed application to bypass Apple’s Gatekeeper security mechanism. By leveraging a valid developer signature, it evades macOS’s built-in protections designed to prevent untrusted software execution. Although no known exploits are currently active in the wild, the malware’s ability to stealthily exfiltrate sensitive data poses a high risk. The threat primarily targets macOS systems and can compromise confidentiality by stealing user information. European organizations using macOS devices are at risk, especially those in sectors with high-value intellectual property or sensitive data. Mitigation requires strict application whitelisting, monitoring for unusual data exfiltration, and verifying app signatures beyond Gatekeeper’s default checks. Countries with significant macOS adoption and critical technology sectors, such as Germany, France, and the UK, are more likely to be affected. Given the malware’s stealth, ease of bypassing Gatekeeper, and potential data loss, the severity is assessed as high. Defenders should prioritize detection of signed but suspicious applications and enforce multi-layered endpoint security controls.