So coin mining is a losing game, then ?
"But even if we allow a zero cost for hardware and power (the costs of the bots and their power are borne by the victims), the difficulty level of common mining algorithms and the nonspecialized hardware that the malware infects make this a futile effort."
Okay, I can understand that a smartphone is nowhere near the level of power required to mine any whatevercoin, so that's out by definition. But here, they're apparently saying that even on PCs without electrical costs, it is not worthwhile. At that point, I have to wonder if coin mining has not become just a fools' game.
Not that I'm going to, but I have an Intel i7 4930K on a system with 16GB of DDR3 and a Radeon HD 7850 with 2GB of memory on-board. I have difficulty believing that that kind of hardware would not be able to mine something of a profit even though I am the one paying for the electricity and hardware upkeep.
So, why would a botnet herder not find any profit on my machine if he took it over ? He's not paying the electricity, I am. He didn't pay for the hardware, I did. You take those costs out and it seems logical to get some coin mining going, it should supplement the revenue stream nicely.
Instead, they're saying that its a zero-sum game. I don't get it.