Mozilla Introduces Malicious Extension Blocker for Firefox to Combat Cryptocurrency Theft

Mozilla has introduced a new protective feature aimed at blocking malicious extensions for the Firefox browser that steal cryptocurrency from users.

In reference to the FBI’s Internet Crime Complaint Center report from 2024, Mozilla highlighted that global losses due to cryptocurrency-related fraud reached $16.6 billion, with $9.3 billion occurring in the United States alone—an increase of 66% compared to 2023. Scammers employ various tactics to deceive individuals, but cryptocurrency wallet phishing schemes are becoming increasingly prevalent. One common method involves the use of harmful browser extensions.

The new system creates risk profiles for each wallet extension available in the store. It automatically raises alerts once specific thresholds are met, allowing developers to take greater care in managing their extensions and removing harmful ones before users download them.

«The initial layer of protection involves automatic indicators that assess risk profiles for wallet extensions listed on addons.mozilla.org. When a wallet extension reaches a certain risk level, our reviewers are prompted to conduct a more thorough examination. If the extension is found to be malicious, it is promptly blocked,» Mozilla explained.

Andreas Wagner from the Add-ons Operations team, who oversees the security and content review system on addons.mozilla.org, noted that his team has identified and removed hundreds of malicious extensions, including fraudulent cryptocurrency wallets, over the past few years.

«It’s an ongoing game of cat and mouse, as developers strive to circumvent our detection methods. Always check your cryptocurrency wallet’s website for its official extension and only use those that are linked from the official site,» Wagner advised.

At the end of May, the stable version of Firefox 139.0 was released, featuring enhancements, updates, and fixes for bugs found in the previous stable version. This update includes support for full-page translations on Firefox extension pages, compatibility with transparent PNG images when pasted in Firefox, and improved performance for HTTP/3 loading.