Here is the info from Grok copied verbatim: (from a specific question regarding syncjacking)
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Browser sync features, such as those in Google Chrome, allow users to synchronize data like passwords, bookmarks, browsing history, and extensions across devices via a cloud account. However, this convenience can be exploited by malware and criminals to circumvent security controls, including enterprise policies, antivirus detection, and user permissions. Attackers can leverage sync to escalate privileges, steal sensitive data, disable protections, and achieve persistent access without raising immediate alarms.
One prominent method is through a technique called “Syncjacking,” where malicious browser extensions hijack the sync process to take over the user’s browser profile and, ultimately, the entire device.
This exploits the trust in sync mechanisms by authenticating the victim’s browser to an attacker-controlled account (e.g., a managed Google Workspace profile), allowing the push of unauthorized policies that bypass controls like safe browsing or extension restrictions.
Once synced, attackers gain access to stored credentials and history, enabling data exfiltration or further manipulation.
For an example, consider a scenario where a user installs a seemingly benign Chrome extension (often distributed via phishing or disguised as a productivity tool). The extension silently links the browser to the attacker’s managed profile.
It then intercepts a legitimate file download—such as a Zoom update from the official site—and replaces it with a malicious executable containing an enrollment token.
When the user runs this file (believing it to be genuine), it enrolls the browser as “managed” under the attacker’s control, allowing them to disable security features, install additional malware, redirect traffic to phishing sites, and exfiltrate data like passwords or session cookies. This can escalate to full device hijacking by modifying registry entries to access native apps, enabling surveillance (e.g., activating the camera or microphone) or executing arbitrary commands—all while evading traditional endpoint detection tools, as the attack originates from within the trusted browser environment.
This example illustrates how browser sync acts as a blind spot in security, as it requires minimal user interaction beyond initial extension installation and can bypass blacklists or permission checks.
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After reading the lengthy issue how can we prevent this? By not syncing of course. And how to do this depends on the environment (one may be able to deny the sync capability on the network even if someone tries to sync anyway.
Setting the security policy creates a culture of security and thus lets people know where one stands when new functions are pondered.
Check my security policies – and my contact at fixvirus (this is a Fixvirus Blog)