Bing to Yandex combined with Edge deflector (https://github.com/da2x/EdgeDeflector) lets you search through cortana tool bar with Yandex instead of Bing. Based on Bing to Google by Louis Grasset

Bing to Yandex | Firefox Add-on
Bing to Yandex is a Firefox add-on that allows you to search through the Cortana toolbar with Yandex instead of Bing. It is a combination of Bing to Google and Edge deflector, developed by Louis Grasset.
Add-on stats
Manifest V2
Firefox on Android: No
Permissions:
- webRequest
- webRequestBlocking
- https://bing.com/*
- https://*.bing.com/
Size: 59.14K
Email: in*****@livansky.ru
URLs: Website
Source: Firefox Browser Add-ons
Add-on safety
Risk impact
Bing to Yandex requires some sensitive permissions that could impact your browser and data security. Exercise caution before installing.
Risk impact analysis details
- Critical Grants access to browser tabs, which can be used to track user browsing habits and history, presenting a privacy concern.
- Critical ******* ****** ** *** ********* ******** ********
Risk likelihood
Bing to Yandex has earned a fairly good reputation and likely can be trusted.
Risk likelihood analysis details
- High This extension has low user count. Unpopular extensions may not be stable or safe.
- Low **** ********* *** ******* **** **** * ****** **** ***** ******** *** **** ****** ** ** ****** *** *****
- Low **** ********* *** ***** **** **** * ****** **** ***** ********** *** **** ****** ** ** ****** *** *****
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