[johnyzee]

> FBI assesses with high confidence that [...] malicious actors can [...] use botnets to generate bitcoins.

As far as I understand bitcoin (which isn't too far, admittedly), the generation of bitcoins is actually encouraged, and only possible within some well-defined boundaries which basically just ensures that bitcoins are put into circulation up until it hits the fixed limit. Maybe someone could clear that up for me? In that case the "malicious actors" would actually be performing a useful service for the bitcoin ecosystem.

[ewillbefull]

Interestingly botnets are probably a month away from being unprofitable for mining Bitcoins, in fact GPUs will be unprofitable for mining Bitcoins all-together. ASIC devices are being shipped over the next six months which will increase the mining difficulty substantially.

[LaRakel]

The benefit is that the electricity bill goes to the owners of the infected computers.

What does a botnet cost?

[eric_bullington]

I think the comment is referring to opportunity cost, since botnet's can also be used for other profitable activities, which may bring in more money than bitcoins (such as renting them to interested parties).

[avar]

Generating Bitcoins is CPU or GPU bound. There's a lot of profitable things you can do with botnets that don't compete for those resources.

[jbri]

There's opportunity cost in using it for yourself instead of selling the use of it to other people.

[Scaevolus]

It's malicious in the sense that infected machine resources are being used to directly turn a profit for the controller.

Other ways of profiting off botnets include renting out DDoS and spam capabilities.

[sliverstorm]

Not just turn a profit for the controller, but incur a cost for the victim. I measured my computer the other day; when I start mining, my power draw jumps 160 watts, and I have a fairly efficient machine.

[Nursie]

Yes they would be performing a useful function for the bitcoin ecosystem.

No, it's not acceptable to hijack thousands of computers through malware and use their processing power and electricity to mine bitcoin for you. That's why they're malicious, the computers they're using aren't theirs.

[rmc]

The malicious part is because the resources to mine the computers (physical hardware and electricity costs) are born by someone else (the owner of the infected computer).

[pdog]

If an attacker controls more than 50% of the Bitcoin network's computing power, they can manipulate transactions. Also, an attacker can fill the network with clients controlled by him, which might be helpful in the execution of other attacks.