The browser extension "GasNow" available for Chrome/Brave allows you to easily keep track of ETH gas price and set up alerts. It has been downloaded by 10 000+ users, ranking it the second most dowloaded gas tracker extension.

While usefull, a few days ago the extension was updated :

This extension now asks you to be able to have access and modify what's in your clipboard.

This is a MAJOR security flaw. Basically if you copy a wallet address to transfer funds, this extension can now identify this address and switch it with another one when you paste it, which will result (if you don't check what you are pasting) in your funds being sent to another address, and thus, stolen.

If you are currently using this extension, uninstall it ASAP !!!

If you are not using it, but another similar one, check the permissions you granted because there is a lot of other extensions using this technique...

Edit : This permission has been deleted. Have a look at u/Snarkie3 comment that shares a statement from GasNow team about this matter https://www.reddit.com/r/CryptoCurrency/comments/nv25pc/-/h10wdyd