Monero is the most popular cryptocurrency among cybercriminals, believe researchers at king’s College London and Madrid University Carlos III.

The document States that 4.32% of the outstanding Monero coins (worth about $56 million), extracted illegal ways. According to calculations, only in the world has 4.4 million malicious programs mining this cryptocurrency.

“One of the main reasons for the success of this criminal business is the relatively low cost and big return on investment” — note the researchers.

ForkLog previously reported about a new type of hidden miner for Monero, which is able to “evolve”.