Clam said it contains a coinminer: adblockultimate@adblockultimate.net.xpi Js.Coinminer.Generic-7132237-0

Update: This is still a problem.
Also, https://forums.malwarebytes.com/topic/214257-adblocker-ultimate-inject-coinhive-miner-script-into-browser/

Works very well. It does what it says it does!

Doesn't block everything, but does block most adds. Definetly there is room for improvement, but still does it's job well

Breaks websites and keeps interfering with login pages. Have to constantly disable on sites just to be able to log in and then re-enable the add-on on the site.

Cuidado es un fraude, si vas a realizar un pago en mi caso a mercadopago mejor eliminen esta extension, crea paginas falsas de mercadopago para que deposites en su cuenta y no en la tuya. Me robaron mi dinero. :´(

YouTube no longer works in Firefox. As soon as I disable this add-on it works. Boo!

A very useful add-on. Thank you very much.

very good