Mozilla Firefox users are facing a growing threat: a flood of malicious browser extensions posing as legitimate cryptocurrency wallets. These fake add-ons, often disguised as MetaMask, Phantom, or Trust Wallet clones, are designed to steal sensitive data, drain crypto holdings, or infect devices with malware.

How the Scam Works

Cybercriminals upload fraudulent extensions to Firefox’s add-on store, sometimes using fake developer credentials or impersonating real projects. Once installed, these extensions may:

• Steal seed phrases & private keys by mimicking wallet login screens.
• Replace wallet addresses in clipboard transactions (a tactic called “address swapping”).
• Inject malicious scripts to monitor browsing activity.

Many of these scams slip through automated checks by appearing harmless at first, only to update later with malicious code.

Why Is Firefox Particularly Vulnerable?

While all browsers face extension-based scams, Firefox’s more open submission process (compared to Chrome’s stricter vetting) has made it a frequent target. The problem worsened after Firefox phased out its legacy extension system, forcing developers—and scammers—to adopt WebExtensions, which can still be abused.

How to Protect Yourself

1. Only download from official sources (e.g., MetaMask.io, not third-party sites).
2. Check reviews & developer info—fake extensions often have few downloads or generic dev names.
3. Monitor permissions—a wallet extension shouldn’t request access to unrelated data.
4. Use hardware wallets for large crypto holdings to reduce exposure.

Mozilla’s Response

Mozilla has removed some flagged extensions, but the volume of new submissions makes it a game of whack-a-mole. The company advises users to report suspicious add-ons via its Blocklist page.

The Bigger Picture

This surge highlights a broader issue: browser extensions, despite their usefulness, remain a weak link in cybersecurity. As crypto adoption grows, so do phishing tactics—making vigilance essential.

Have you encountered a fake wallet extension? Share your experience below.