https://arstechnica.com/information-technology/2018/02/ad-network-uses-advanced-malware-technique-to-conceal-cpu-draining-mining-ads/

The rise of drive-by cryptocurrency mining on a growing number of websites has led to a renewed demand for ad-blocking software. Web users are seeking new ways to ward off hidden code that saddles computers with resource-draining coin mining. Now some miners are employing a trick first popularized by botnet software that bypasses ad blocking.