Netcraft has updated its browser extension to add protection against malicious JavaScript, including shopping site skimmers and web miners.

The Netcraft Extension now protects against malicious JavaScript

Shopping site skimmers are malicious JavaScript programs that steal your payment card information when you checkout on a compromised online store, and send it back to a fraudster to use later. These attacks have affected a large number of online shops, and are invisible to even the most vigilant shoppers as there is no visual change to the page.

Web miners are malicious JavaScript programs inserted by fraudsters into a website that let them steal your CPU power to mine for cryptocurrency using your browser without your consent. Browsing a website with a web miner can often slow down your computer by consuming its resources.

Netcraft proactively scans for new shopping site skimmers, web miners, and other malicious JavaScript on the web. In the past six months, we have found malicious JavaScript affecting over 70,000 sites on over 29,000 distinct IPs. We have identified these attacks on high-profile sites such as Cleor (a large French jewellery retailer), Misfit (a wearable devices brand), and Arctic (a PC components and accessories retailer), as well as on the personalized merchandise stores for dozens of sports clubs, including Southampton’s and Swansea’s.

A well-hidden shopping site skimmer

By using the Netcraft Extension you can get protection from these types of attack as soon as we detect them. It was first made available for Internet Explorer in 2004, Firefox in 2005, Chrome in 2012, Opera in 2013, and Microsoft Edge earlier this year.

Select your browser to download the Netcraft Extension now:

If you already have the Netcraft Extension installed your browser will update it automatically.

The Netcraft app for Android also provides protection against these attacks, while the Netcraft app for iOS provides protection against phishing attacks.