In a world where we keep our most sensitive and vital information on computers and the internet. It's a worrying thought to imagine someone remotely using your computer's power to further their own financial gain.
With that in mind, it's worth knowing about, and learning to protect yourself against, the threat of cybercrimes such as 'cryptojacking'.
Cryptojacking, for the uninitiated, is a technique being used by criminals to harness the power of other computers remotely in order to run programmes that mine for cryptocurrencies such as Bitcoin.
In short, your computer is working in the background to harvest Bitcoin for someone else, making them money.
This strange practice has been something of a niche concern until recent times, but as the market for crypto grows, so do the number of people looking to get their digital hands on it in ever more nefarious ways.
To begin with, it's worth pointing out that Bitcoin mining is time-consuming, and uses a whole heap of energy.
That energy has to come from somewhere, and needs to be found cheaply if you're going to turn a profit out of it. That's where the criminals step in.
Cryptojacking is the unauthorised usage of someone else's computer to mine cryptocurrency.
There's a few ways that you can become a cog in this machine.
You might receive a malicious link within an email, which when clicked downloads a cryptomining code onto the computer, which then runs in the background.
Alternatively, the hackers might infect a website or a pop-up advert with the same code, which then auto-runs once it appears in the browser.
Whichever way it happens, the code is working away there in the background, sapping away your energy and CPU.
You might notice that your computer is over-heating, or running slowly. That could be a sign that it has been harnessed by the criminals.
Whilst the phishing-style emails are pretty standard, the technology that performs the remote mining is anything but.
Alex Vaystikh, CTO and co-founder of online security firm SecB, said: "Attacks use old malware tricks to deliver more reliable and persistent software [to the victims' computers] as a fall back."
It's also possible that some codes can use worming techniques to infect other devices on a network or server, so if one goes, the others soon fall.
Sophisticated stuff, really. It's only likely to get more technologically advanced, too.
Marc Laliberte, threat analyst at network security solutions provider WatchGuard Technologies, told CSO Online: "Cryptomining is in its infancy. There's a lot of room for growth and evolution."
So, how do you stop them getting onto your machine?
The simple truth is, there is no one way.
In order to give yourself the best chance of avoiding getting cryptojacked, you need to be really careful with your internet security as a whole.
Get yourself some anti-virus software, and only download things from places that you trust.
Couple that with keeping vigilant and watching for malicious emails and phishing scams - if in doubt, don't click on it - and you have a chance of avoiding your computer becoming compromised.
Oh, and adblocker software is a useful tool to avoid mining site and pop-ups.
If you're worried, you can check your CPU usage and processes. If the CPU is particularly high, you may have a problem.
Although, some of the software could even make that appear normal. It's an absolute minefield.
It's a terrifying world out there, but if you're careful enough you might avoid getting ensnared by the criminals.
Chosen for YouChosen for You
Most Read StoriesMost Read