A recent cyberattack involving fake advertisements on Facebook has targeted users of the Bitwarden password manager, pushing a malicious Google Chrome extension. The fraudulent campaign, identified by Bitdefender Labs, started on November 3, 2024, and impersonated Bitwarden’s official website. The ad warns users about an outdated version of Bitwarden, urging them to click a link to update the program for security purposes. The link, which seems legitimate, directs users to a website resembling the official Chrome Web Store. However, the page is a fake, and rather than automatically installing an extension, users are prompted to download a ZIP file containing the malicious code.
Upon installation, the extension appears as a legitimate version of Bitwarden, labeled as “Bitwarden Password Manager” version 0.0.1. The extension, however, is far from harmless. It collects sensitive information from users, including Facebook cookies, IP addresses, geolocation data, and Facebook account details. These data are then transmitted to a Google Script URL controlled by the attackers. The extension also manipulates the browser’s document object model (DOM) to create the illusion of a legitimate process, such as displaying fake loading messages to distract users from its malicious activities.
This type of attack highlights the growing risks of malvertising campaigns, where attackers exploit popular platforms like Facebook to distribute malicious software. The attack’s success relies on users’ lack of awareness about how extensions should be safely updated and installed. Many users may not recognize the dangers of downloading extensions from unofficial sources, which can bypass security checks when installed in “Developer Mode” on Chrome. The attackers’ use of a ZIP file, which requires manual installation, further complicates the situation, making it more difficult for security systems to detect the threat.
To avoid falling victim to this type of attack, users should exercise caution when clicking on unsolicited links, especially those promising software updates. Bitwarden users, in particular, are advised to ignore any ads prompting an extension update, as Chrome automatically updates extensions when a new version is released by the vendor. Extensions should only be installed from the official Chrome Web Store or through trusted sources like Bitwarden’s official website. Users should also be vigilant about the permissions requested by extensions and avoid granting excessive access to sensitive data, such as cookies and browsing information.
