Quote:Coin mining focused malware has seen a massive increase in activity in the second quarter of 2018, as the number of samples detected has grown by 86% according to a report by McAfee Global Threat Intelligence.

The samples collected and added by McAfee into its database come from its own crawlers and spam traps, as well as customer submissions other industry sources.
As reported by McAfee, the number of total coin miner samples grew significantly during Q2 2018, with an excess of 2.5 million new samples being added to their malware database.