There seems to be a crypto-mining malware called CoinHive embedded in dorikaze. Gist of it is that it's a program that site owners can embed in the HTML to support their websites, which is fine IMO if disclosed. Though it's more likely to be used like it is here on DK, without any disclosure. Threat from Coinhive or crypto-mining in general is pretty small outside using up more of your CPU than is actually needed for your task.