This is a scam that has been going on for years that has adapted its techniques over time.
We used this botnet as a case study back in 2018 when doing analysis on finding Twitter bots at a large scale. You can find the paper here [0] - the cryptocurrency scam botnet starts on page 28. You can also find the talk here [1] where we go into a little more detail. In full irony, someone tried sharing our research on Twitter, and one of the bots replied to the thread trying to spread the scam.
[0] https://duo.com/assets/pdf/Duo-Labs-Dont-At-Me-Twitter-Bots....