Feature Kaspersky added in 2015 also made it possible to be ID'd across different browsers
Antivirus software is something that can help people be safer and more private on the Internet. But its protections can cut both ways. A case in point: for almost four years, AV products from Kaspersky Lab injected a unique identifier into the HTML of every website a user visited, making it possible for sites to identify people even when using incognito mode or when they switched between Chrome, Firefox, or Edge....
https://arstechnica.com/information-technology/2019/08/kaspersky-av-injected-unique-id-into-webpages-even-in-incognito-mode/