The plugin is called Privacy Alert and is available from the Chrome Web store. It will warn users if personal data is at potential risk of being stolen when they log in to a website.
A pop-up will appear on the right-hand top corner of any Web page when there is a chance that data theft may occur.
A statement from the company said: "“Over the past couple of years, businesses have made headlines for falling victim to these eSkimming attacks, such as those perpetrated by the hacking group Magecart.
"Privacy Alert will alert you if it detects that third-party sources access or have the ability to access the private information that you enter into form fields or is stored in cookies, allowing you to decide if you feel safe continuing to provide the website with your information," the statement added.