If I understand the OP correctly, he means could the blockchain be attacked by a vast number of infected hosts, causing a malware-induced change in the consensu

If I understand the OP correctly, he means could the blockchain be attacked by a vast number of infected hosts, causing a malware-induced change in the consensus of nodes, allowing BTC to be illicitly acquired, spent, or produced. I believe controlling a massive number of nodes in the network via infection techniques like WannaCry used would open the door for many actual and hypothetical attacks. Please see the Bitcoin Wiki page titled Weaknesses [1] for more details about attacks involving the control of network resources. More realistically, a simpler attack would be to go for control of the wallets if you have that kind of access to the infected hosts. However, if an actor had an interest in devaluing Bitcoin, to buy after a crash and sell after recovery perhaps, or just destabilize users' trust and destroy it (states?) then there could be a lot of profit in it I believe. Bitcoin has many competitors and enemies, is this something we should worry about? [1] https://en.bitcoin.it/wiki/Weaknesses https://en.bitcoin.it/wiki/Weaknesses