THREAT INTELLIGENCE
AmnesiaStealer: New macOS Infostealer Hijacks Live Browser Sessions

Peer Review

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5-star rating
4.8

Proven Trust

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CVE-2020-9771

August 17, 2026

Executive Summary

AmnesiaStealer is a Rust-based macOS infostealer distributed through ClickFix-style social engineering, designed to steal credentials, browser data, keychain material, cloud and crypto assets, and hijack authenticated browser sessions.

Key Details

Affected Platform

Attack Surface

Recommended Action

Affected Environment

macOS endpoints, particularly systems using Chromium-based browsers, Apple Keychain, Safari, Telegram, cryptocurrency wallet extensions, and devices with excessive Full Disk Access privileges.

Operational Impact

Successful infection enables credential theft, keychain and browser-data compromise, cryptocurrency wallet theft, persistent access, and live hijacking of authenticated browser sessions across services such as email, banking, cloud storage, and SSO-enabled SaaS.

Technical Root Cause

The campaign relies primarily on social engineering rather than a software vulnerability, tricking users into executing an encoded shell command and supplying their macOS password. Legacy TCC bypass attempts linked to CVE-2020-9771 are also present.

Recommended Mitigation

  • Enforce current macOS patch levels, restrict or monitor unsigned and ad-hoc-signed Mach-O execution from /tmp, apply least-privilege Full Disk Access, and train users never to paste untrusted Terminal commands from websites.

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References

Jamf Threat Labs
SecurityWeek
BleepingComputer
GBHackers
SC Media
CybersecurityNews
MacTech

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