If you have installed a free wordpress plugin or theme, with hidden or “additional functionality” and your website is now using additional processing resources:

Whether the resources your website or web application is using is being used to search for life on other planets (SETI) or for minining of Bitcoin or for other crypto currency or for hashing password files, or whatever, it does not matter, as long as you remain within the allocated resources for your hosting plan and if you do not breach the Nkosi AUP and the Terms & Conditions of service applicable to all clients (Your web application is not illegally trying to breach cloud security, for example)

Please note that Nkosi Web Hosting (Pty) Ltd does not consider Bitcoin or Crypto currency mining as abuse, as long as you remain within the allocated resources for your hosting plan and if you do not breach the Nkosi AUP and the Terms & Conditions of service applicable to all clients. – But, please do be aware that the hosting costs and the return on specifically Bitcoin mining, is negative (It will cost you more money than you will earn)

If you are intentionally mining crypto currency, even at a financial loss to yourself, this is also perfectly acceptable, as long as you remain within the resource limits of your specific hosting plan and if you do not breach the Nkosi AUP and the Terms & Conditions of service applicable to all clients.