Trojan virus that infected multiple computers then used them to mine Bitcoins, without the PC owners knowing what is really happening. Bitcoin miners are then paid for the mining that they do for the network and this is the part of where hackers invade other peoples PCs to make their work faster and easier. Kaspersky Lab says that Trojan is not only used for mining Bitcoins unethically but also for other immoral doings that is why it is highly advised to be careful in receiving internet messages and downloading programs.”]
Source: https://informationsecuritybuzz.com/articles/trojan-virus-can-turn-pc-bitcoin-miner-without-knowing/