I was hacked around 05/2024. If I messaged anyone about an eSports logo competition or something else, that is part of a scam! I don't know who the scammer also messaged, but know that this is NOT me and do not click on the link nor interact with the site. If you have, I'm sorry. Please follow this forum post to de-authorize your keys.

https://www.reddit.com/r/SteamScams/comments/16u7v2k/esports_logo_voting_scam/

TL;DR
For most people: https://store.steampowered.com/twofactor/manage
For those who use API, additionally: https://steamcommunity.com/dev/apikey