Browser Extensions Pose Hidden Cybersecurity Threat, Finnish Agency Warns

Finland's Transport and Communications Agency, Traficom, has issued a cybersecurity warning about browser extensions. These add-ons, designed to improve usability and boost productivity, can carry serious security risks. According to Traficom’s Cybersecurity Centre, many extensions request broad permissions that grant them access to all content handled by the browser, including visited websites and data entered into online forms. The agency explains that some extensions have poor security standards or are outright malicious software. Such harmful tools can redirect users to dangerous websites, leak typed information to cybercriminals, or manipulate browser content to display deceptive ads. Traficom notes this is not a new tactic, threat actors have exploited browser extensions for several years. Traficom advises users to install extensions only from official sources and carefully assess both the developer’s credibility and the permissions requested. Particular caution is needed if an extension seeks wide-ranging access to web content or browsing history. Browser makers act on reports of harmful extensions by removing them from their stores and sometimes directly from users’ browsers. To stay protected, Traficom recommends keeping the number of installed extensions as low as possible, regularly removing unused ones, and ensuring both the browser and essential extensions stay up to date with the latest security patches.