Mirai, Bitcoin, and numeracy

Newsweek (the magazine famous for outing the real Satoshi Nakamoto) has a story about how a variant of the Mirai botnet is mining bitcoin. They fail to run the numbers.

The story repeats a claim by Mcafee that 2.5 million devices were infected with Mirai at some point in 2016. If they were all mining bitcoin, how much money would the hackers be earning?