The problems with different kinds of frauds against cryptocurrencies, or rather crypto-assets since one can argue whether we are talking about real currencies, will not disappear in 2018. The problems will most likely evolve and increase.
Focus will most likely move away from attacks on online banking services and the use of ransomware that we have witnessed during the last couple of years. Such methods are rather difficult, dangerous, and actually not that effective. Now the criminals can find less dangerous and perhaps more lucrative ways to make money by using botnets to do crypto-mining through home computers, company servers and by using malicious scripts on websites.
Miners has now started to look beyond these sources. There is the whole vulnerable internet of things for them to feast on: IP cameras, smart-homes, fridges, vacuum cleaners, coffee machines and what have you. They’re much easier to hijack into botnets because their security is often weak and security updates are for some reason generally of lower priority than for other components in the network. Examples of this - the Mirai and BrickerBot botnets demonstrated this perfectly.
And not least - miners are starting a process of legalization. In the small print in the licensing agreement (or in a pop-up in the interface), the product will inform the user that it will take a small bite of processor power as payment. Software, hardware, web services, media content – practically everything on the internet can be monetized through the use of mining. The users will in many cases be aware of this and be for it, at least until it takes up all capacity in the CPU making access to the device non-existing. People working in companies with supercomputers have been noticed using the CPUs for mining off office hours (sometimes during office hours) and is something for CTIOs out there to watch out for since it can empose devastating effects on your business and reputation.