Hijackers are bad guys that overtake something and use it for a different purpose. There is no shortage of action movies involving criminals seizing a plane, taking hostages and re-routing the flight to land at a different location. Ransom, preferably the untraceable kind, usually comes into play along the way. Cryptojacking is a lot like hijacking but instead of planes, our computers are overtaken to mine cryptocurrency. Since we are all merely digital passengers through our devices, we become the hostages. The ransom demands do not come in the form of money, but rather, stolen energy in the form of CPU or GPU cycles from our devices. So if these cryptojackers are making no demands for money nor data, what exactly are they stealing from us?

Cryptocurrency mining requires serious juice

The energy used to mine bitcoins currently requires approximately 215 kilowatt-hours for each coin generated. And this requirement increases slightly with every new coin creation. In New Jersey, where our corporate headquarters is located, the cost in energy to mine one bitcoin is roughly $5,011 USD, whereas in Hawaii it costs roughly $9,483 USD per Market Watch’s state-by-state cost breakdown. This cost disparity is based solely on the price of electricity delivery. And while all cryptocurrencies have different monetary values and not all blockchains are created equally, we will only be dealing with Bitcoin here to simplify matters and because it’s the most popular digital currency by far.

Cryptocurrency miners are not thieves but are actually performing crucial functions within the blockchain by solving complex cryptographic problems to validate transactions across the Internet. In order to avoid falsified records of ownership, miners verify all Bitcoin network transactions in each block. For their work in each block of the chain, or blockchain, miners are rewarded with bitcoins. But all of this mining comes at a price. Electric consumption to mine the Bitcoin network has dramatically risen in parallel with the cryptocurrency’s value. It seems that everyone wants to become a miner these days so instead of moving to areas with the best weather or schools or lowest tax rates, wannabe miners are setting up camp in towns with the lowest kW-hour rates. Back in November, Motherboard reported that one Bitcoin transaction used as much energy as your house in a week.

CPU attention span

We have all experienced the annoying spinning pinwheel (Mac) or hourglass (PC) on our computers when trying to access a file or launch an application, but have you noticed an even more sluggish computer lately? You may have already been cryptojacked. Your precious CPU cycles are being used to operate your computer normally, while, at the same time, mining cryptocurrency without your knowledge or permission. SETI@home and Sony Playstation’s computer clusters both behave similarly except that these are academic endeavors that users must opt into in order to participate.

So cryptojackers are trying to give users just enough power so that normal computing functions will not be hindered. According to 9to5mac.com, Apple recently pulled Calendar 2 from the App Store for mining cryptocurrency in the background. Users were treated to premium calendar features in exchange for use of CPU cycles that they would never miss. So the developer was upfront about the exchange. However, while mining Monero, a bug in the code would use 200% of the CPU which violates Apple’s app developer policy regarding unnecessary burden placed on iOS devices. In the 3 days that the app was publicly available, it managed to earn $2,000 of Monero through mining. It has since been pulled and re-introduced to the App Store minus the cryptomining features.

Not nearly as many cryptomining programs are as upfront. Both malware and legitimate software (hiding crpytomining terms in the EULA) have been discovered stealing CPU cycles. This mining generally occurs through thousands of users via their browser. And it’s not just innocent computer users that are victims of cryptojacking but also some high-profile companies. BBC reported that a Buenos Aries Starbucks’ Wi-Fi service was surreptitiously hijacking connected devices to offer free Internet while mining cryptocurrency on those same devices.

Cryptocurrency popularity and soaring value

“One in three millennials will own cryptocurrency by the end of 2018,” according to a survey by the London Block Exchange. And due to its ease of mining and difficulty to trace, Monero has become one of the most popular cryptocurrencies for investment, mining and general use. Whereas, Bitcoin requires high performance CPU and GPU, Monero can be effectively mined using more affordable hardware. Monero has a current total market value of $4.3 billion and is ranked in the top 20 cryptocurrencies.

How can we protect our devices?

When hackers take over our devices, they are taxing them without our knowledge. The used electricity is on our dime and our computer’s processors are pushed to the limit. This produces a lot of heat which will likely shorten its life. If they are targeting a mobile device, the damage can be even greater. All mobile devices contain Li-ion batteries which are prone to explode when exposed to too much heat. Be sure to watch your devices for unusual lagging and slowness of operation and always keep an eye on the operating temperature. Keep your OS up to date and use software applications to combat cryptojacking such as avast. There are also some effective cryptojacking blockers on the market such as NoCoin. A cryptojacking blocker essentially adds a browser extension to block a list of domains specifically associated with the mining code.

With the continual rise in value and popularity of cryptocurrencies, we will likely see a growing list of hackers joining the cryptohijacking bandwagon. But even if you are not actively investing in or using cryptocurrency, there is a very real chance that you’ll be a victim of cryptojacking.

Full Disclosure – I am an advisor to BlockSafe Technologies which has patented technology to effectively secure blockchains and cryptocurrencies. This blog was originally written for and posted on BMC Blogs.