Ask HN: Does anyone what a "RiotCache.dat" file was doing in my EFI partition?

On 5 April 2026 I uploaded my security solution to my Claude account. I have DO NOT use my data selected. On 7th April 2026 they announced Mythos, solving the exact same problem my system solved. On 15th May I uploaded my scientific research tool to another platform. 2 Days later Google announced Google for Science. Not just a high level match. The entire pipeline is functionally identical. This isn't about me. They are literally harvesting us for our data. This isn't the first or second time this has happened. In 2016 I disclosed a system under NDA to Arrow Electronics who were partnered with IBM at the time. That system was later rebranded with new terminology and patented by Google as the transformer which now powers nearly all AI systems. Feel free to reach out to me via LinkedIn Wesley Schouw

It's part of Vanguard. As Vanguard hooks itself into the Windows kernel through a low level (ring 0) system driver and all partitions except the system / UEFI service partition are not available at boot/init time (which is the moment Vanguard is loaded and activated) it uses the UEFI service partition to dump files it temporarily or permanently requires.

If you no longer play any of Riot's games (which you should if you really care about the integrity of your system) and Vanguard is no longer active on your system you should be able to safely remove it.

It’ll be the Riot Games Vanguard anti-cheat. It’s very invasive. https://en.wikipedia.org/wiki/Riot_Vanguard

Riot Games client data? Aka anticheat root kit? Did your old laptop have a riot game on it?

must be added by chrome