Mozilla will add a new security feature to Firefox in October that will prevent malicious websites from automatically downloading and installing malware on a user's computer.
This type of attack called drive-by download has been around for two decades and usually happens when users visit a site containing malicious code posted there by an attacker.
The role of malicious code is to abuse legitimate functions / attributes in browsers and web standards for starting automatic file downloads or download prompts, hoping to trick the user into running a malicious file.
There are many types of drive-by downloads, depending on the browser capability that attackers choose to use.
Browsers such as Chrome, Firefox and Internet Explorer have gradually developed various forms of protection for autofocus, but of course they can not offer 100% protection due to the changing landscape of online attacks, with the attackers always finding a way to invade.
The last round of protection against drive-by downloads is called "sandboxed iframes", which are often used to load ads and embedded widget (videos, music tracks, podcasts) on third party websites.
The idea is that websites rarely make downloads through "sandboxed iframes", as most of these widgets are commonly used for embedding. content.
Chrome is blocking them for the first time downloads starting with the "sandboxed iframes" with the release of Chrome 73 in March 2019, with this option being completely removed in Chrome 83 in May 2020.
This week, Firefox announced something similar. Starting with Firefox 82, which is scheduled to be released next month in October 2020, Firefox will block all downloads of files from a "sandboxed iframe".
The only situations where downloads will be accepted are if the site owner or widget provider has an "allowed download" flag in the iframe. However, most do not do this because it is a security risk and that is why they use "sandboxed iframes" instead of the classic iframes.