Android users exposed to drive-by cryptomining in one of the largest campaigns that we have detected so far. Visitors are presented with a CAPTCHA to solve in order to prove that they arent bots, but rather real humans. We estimate that the traffic combined from the domains we identified so far equals to about 800,000 visits per day, with an average time of four minutes spent on the mining page. Because of the low hash rate and the limited time spent mining, this scheme is only netting a few thousand dollars each month.”]