Regarding Yandex. The founder sold [3] the assets (seemingly including the index and Yandex trademark) to VK (Mail.ru) in 2022. VK are known supporters of the war [4]. The founder subsequently renamed [5] his original company to Nebius Group and pivoted towards compute for AI.
[1]: Kagi Community AMA by the founder. Timestamped link: https://www.youtube.com/watch?v=XbmMUGSFldQ
[2] Kagi forums, a response by the founder. https://kagifeedback.org/d/5445-reconsider-yandex-integratio...
[3] https://en.wikipedia.org/wiki/Yandex#2020s
[4] https://www.theverge.com/2022/2/26/22951307/us-sanctions-rus...
I may be wrong here, please correct me if needed, but from what I understood from the news it was actually reverse of that. Yandex during the "smaller" war period, had a Netherlands parent holding to play pretend they are European company, and last year that holding sold their shares back to some Russian companies. So it looks like that it's Europe left Yandex, and not Yandex left Russia. But again, the whole house of shell cards is so complex there that I'm not sure about it.