What is Cryptojacking? Definition and Explanation of Cryptojacking

With the rising popularity of cryptocurrencies, which are an integral component of day-to-day Internet transactions, investors who seek to earn earnings rapidly by computing powerful transactional records for the blockchain network have been interested in the so-called cryptomining service. Since the majority of users cannot afford the expense of specialized or standardized gear for mining, innovative ways have been developed to simplify the process and reduce the needed computing cost. Developers of big cryptocurrency houses have made available executable binaries and mostly browser-side scripts in order to access users' pooled resources and efficiently calculate puzzles for a proof of work. However, bad actors have utilized this feature to introduce harmful scripts and unlawfully harvest data without the knowledge of the user. This cyber-attack, also known as cryptojacking, is covert and hard to assess, creating a loophole in multi-layer protection procedures.

The definition of cryptojacking and an explanation of its workings will be presented at the beginning of this article, after which we'll discuss its various types. Later on, cryptojacking examples from real-world situations, cryptojacking prevention advice, and cryptojacking detection techniques will be presented.

What is Cryptojacking?

Cryptojacking is the unlawful use of a person's or company's computational resources for cryptocurrency mining. Cryptojacking is a cybercrime that involves the unauthorized use of another party's computational resources to mine bitcoin. Cryptojacking, also known as harmful cryptomining, allows hackers to mine bitcoin without having to pay for power, hardware, or other mining resources.

Cryptojacking programs are malware that is installed on a victim's computer through phishing, infected websites, or other malware attack methods, or they are small pieces of code inserted into digital ads or web pages that only run while the victim is visiting a specific website.

How Does Cryptojacking Work?

In the cryptocurrency realm, coin mining is a legal operation that releases fresh cryptocurrency into circulation. The approach works by rewarding the first miner who solves a challenging computational challenge with cash. This problem resolves blocks of validated transactions, which are then appended to the bitcoin blockchain.

"Miners are essentially getting paid for their work as auditors. They validate the integrity of Bitcoin transactions." explained a recent Investopedia tutorial on how Bitcoin mining works. "Mining serves an important purpose in addition to feeding miners' pockets and maintaining the Bitcoin ecosystem: it is the sole means to put fresh bitcoin into circulation".

Earning cryptocurrencies through coin mining often necessitates a significant amount of computing power and energy. Furthermore, the cryptocurrency ecosystem is constructed in such a manner that mining becomes more difficult and the incentives for it diminish with time and with increased mining competition. As a result, real cryptocurrency coin mining is an incredibly expensive endeavor, with costs growing all the time. Cybercriminals reduce mining costs by stealing computer and energy resources. They employ a variety of hacking techniques to acquire access to systems that will perform the computational work illegally and then direct the results to a server controlled by the hacker.

Because the only thing stolen is the victim's computer power, cryptojacking appears to be a harmless crime. However, the use of computational resources for this unlawful purpose is done without the victim's knowledge or agreement, for the profit of the criminal who is making cash illegally. Cybercriminals regard this as a lucrative crime since a high number of infected devices generates a large quantity of money.

The major impact of cryptojacking is performance-related, but it increases prices for impacted individuals and organizations because currency mining requires a lot of electricity and computer resources.

Cryptomining scripts with worming capabilities infects other computers and devices on a target network. This makes them difficult to isolate and remove, a cryptojacker's best financial interest is to retain persistence on a network.

Cryptomining programs include numerous versions that exploit holes in different network protocols to increase their ability to propagate throughout a network. In certain circumstances, the cryptomining code downloads many copies and attempts to execute them all until one succeeds.

What are the Types of Cryptojacking?

Cryptojacking is classified into two categories. The first is focused on infecting the web browser, while the second is based on host-based approaches.

• Browser Cryptojacking: The browser-based solution works by producing content that, when a user visits the webpage hosting it, automatically starts cryptomining software in their web browser. Drive-by cryptomining is another name for this approach. Cryptojackers establish a website with embedded cryptomining JavaScript code and route traffic to it for cryptojacking purposes, or they hack an existing site. Existing websites can be infiltrated by programmatic advertising, which contains malware that displays adverts on websites automatically. This is done without the website owners' awareness, and they have little control over whether or not the software runs on their site.

  Compromised advertising can be placed on a website as pop-unders, which are meant to hide behind windows that are already open on a victim's computer or phone in order to evade detection. This sort of malware use domain creation algorithms to circumvent ad blockers and provide advertisements to all site visitors.

  Cryptojackers can embed JavaScript on websites without the use of advertisements. Some websites even admit that their pages exploit users' devices to execute cryptomining software while they are browsing. This concept has been proposed for additional applications, such as generating income for websites and services and raising funds for disaster relief operations. Cryptomining malware is not saved on the victim's devices in these cases but instead executes only when the victim visits an infected website or fails to notice the corrupted pop-under ad.

• Host Cryptojacking: This strategy functions similarly to regular phishing and malware attacks. Cryptojackers trick victims into clicking on seemingly innocent URLs that install cryptomining software on their devices. All sorts of devices can be affected by host-based cryptojacking. For example, Google Android phones are vulnerable to Trojan horse cryptojacking attacks via Google Play Store applications.

  In addition, cryptojacking malware may infect open-source code and public application programming interfaces (API), infecting machines that download the code or API as well as any applications produced with it. Cryptojackers can gain access to unprotected cloud storage.

  Cryptojacking malware spreads across the network once inside a victim's endpoint, including servers, cloud infrastructures, and software supply chains. Many cryptojacking scripts also include worming capabilities, which identify and deactivate existing cryptojacking malware on a victim's device before replacing it.

How to Detect Cryptojacking?

If you are unsure whether your device is infected with cryptomining malware, pay attention to the most prevalent indicator of malware: an unusually high CPU or GPU load. Because cryptojackers are primarily interested in computational power, concealing the malware's influence is challenging. To make a lot of money with cryptojacking, cryptojackers have to put in a lot of labor. This can occasionally reach 90 or 100 percent.

A loud computer ventilation system or an overheating gadget implies that tasks are happening in the background. As a result, unless you are performing computationally heavy tasks, your device should not overheat. If it happens, it might be a sign of a malware infection. In the worst-case situation, undetected cryptojacking might degrade your device's lifespan due to constant load and increase your energy expenditures.

You should consider the following issues to detect the cryptojacking:

• Examine Your Resource Usage: Check the Task Manager (Windows: ctrl+alt+del) or the Activity Monitor (Mac: Finder > Applications > Utilities > Activity Monitor) to determine whether your CPU resources are at 99% or above. This does not necessarily portend calamity, but if the software eating your resources has no business using.

• Examine Your Browser to See if It Is Secretly Still Active: Close the Internet Explorer (or Chrome, or Firefox) browser window and launch the Task Manager / Activity Monitor to determine if the program is still active. Cryptojackers often operate through your browser and can produce a tiny "pop-up" browser window that hides behind your Start button or toolbar, allowing it to waste computer resources even after you believe you've closed your browser.

• Pay Close Attention to Your Cloud Bills: Cybercriminals can steal your cloud login credentials and use them to mine, but you won't be aware of the problem until the end of the month. Unfortunately, this procedure may be costly. It's similar to discovering a water leak in your home after the fact and then having to repair the damage the following month.

What are the Real Examples of Cryptojacking?

Though it has not touched many people to yet, cryptojacking is a serious problem that impacts companies. It has created far-reaching consequences. The following are some of the world's most infamous cryptojacking attacks:

• Microsoft: In 2019, the respected Microsoft store discovered eight cryptomining applications. The troublesome aspect was that the procedure utilized the resources of users who had installed and utilized the application. Even after the applications were deleted, significant harm was done. Speculations were made that, despite the fact that these apps originated from separate developers, this attack was organized and carried out by a single individual or group.

  The compromised applications included tainted JavaScript and were told to mine Monero. As a result of the task consuming a great deal of energy, the affected devices experienced negative impacts such as slower performance and diminished battery life.

• European Central Water Control System: In 2018, another victim of cryptojacking was identified. It was Europe's central water control system. The cryptomining code was also ordered to mine Monero in this instance. The central operating system of the whole water utility network was compromised by malicious hackers. It was technically the first attack of its type to target the industrial landscape for cryptojacking.

• Los Angeles Times: The Los Angeles Times, one of the top media outlets, has fallen prey to cryptojacking. The attack occurred in 2018 and was directed at the report page. Any mobile or other data-driven device user who viewed this website got infected. Unfortunately, for a longer period of time, this cryptojacking malware remained undiscovered and allowed criminals to mine Monero.

• YouTube: Multiple CoinHive miners were observed operating in YouTube advertisements.

What are the Cryptojacking Tools?

Along with the real cases, you should be familiar with the well-known cryptojacking programs that are employed in these attacks. Some of these cryptojacking programs are listed below:

• Coinhive: It has played a significant part in the emergence of the crypto theft menace, to the point that in 2018 Coinhive was nearly synonymous with crypto theft. Coinhive was sent via a web browser and loaded Javascript files into the sites of users.

• Blue Mockingbird: Blue Mockingbird is an attack that mines cryptocurrency against millions of public servers in India. Server vulnerabilities have been used to execute malware with many components that distributes cryptojacking software.

• Lemon Duck: The cryptojacking program Lemon Duck was found for the first time in 2019, but its efficacy is rising in 2020. Written in Python using a combination of code from open source projects, Lemon Duck can rapidly spread over the network in order to transform organizations' assets into digital money.

• Graboid: Graboid is a worm that spreads via Docker Engine (Community Edition) containers and is responsible for crypto-theft. Graboid is undetected by conventional endpoint security solutions.

• PowerGhost: PowerGhost is a fileless virus that employs natural Windows capabilities to infect workstations and servers on enterprise networks. It advances through remote access techniques or exploits.

• FaceXWorm: FaceXWorm encourages Facebook Messenger users to click on a fraudulent YouTube link in order to download a Chrome extension. The extension essentially hijacks the Facebook accounts of its victims in order to promote the link among their friend networks. FaceXWorm harvests credentials when users attempt to log in to sites such as Google and MyMonero, then redirects users attempting to access real cryptocurrency exchanges to phony websites.

• Black-T: Black-T targets AWS clients whose Docker daemon APIs are exposed.

• Kings Miner: The effectiveness of the Kings Miner virus against unpatched systems reached its peak in March 2020. It has been efficient in eradicating rival malware by attacking Windows-based servers hosting a variety of services.

• WannaMine v4.0: WannaMine v4.0 compromises hosts by exploiting the EternalBlue vulnerability. EternalBlue utilizes binary network distribution files located in the C:Windows folder. Based on a set of hard-coded strings, this form of WannaMine produces a random dll and service name. This is how persistence on the host is ensured.

• BadShell: BadShell is a fileless form of malware that requires no download. It use native Windows processes including PowerShell, Task Scheduler, and Registry, making it tough to detect.

What are the Cryptojacking Prevention Tips and Tactics?

Cryptojacking has become nearly hard to defend against online. This is mostly due to the fact that you have no control over the files installed on other websites. Even with this in mind, there are measures you can do to reduce the likelihood of cryptojacking as much as feasible. Common methods that are used to prevent cryptojacking are as follows:

• Use an Ad-Blocker: Typically, cryptomining scripts are concealed behind advertisements on websites, so if you employ an ad-blocker, you can avoid some types of cryptojacking. Some ad-blockers, such as Adblock Plus, offer a function that allows them to recognize cryptomining scripts.

• Use Special Extensions: NoMiner and minerBlock are extensions that identify cryptomining scripts deployed by hackers on websites.

• Use Antivirus Software: Antivirus software is beneficial if a cryptojacking script has already infected your machine. Similar to ordinary viruses or dangerous malware, scripts may be quarantined and removed. In addition, a great deal of antivirus software provides detection options for cryptomining scripts.

• Use a Firewall that is Updated: This is especially critical if your device is part of a bigger network that has a collective firewall. If you suspect a webpage contains a cryptomining script, it is crucial that the network firewall is updated to prevent you and everyone else in the network from accessing the page over the web. This will prevent bitcoin miners from using your network's resources without your awareness.

• Disable Javascript: The most used script on any website is Javascript, which is why hackers typically conceal cryptomining programs within Javascript components. There are a number of ways to disable Javascript, including the use of a free extension such as Quick Javascript Switcher. You can also utilize a specific feature of the Tor browser to prevent cryptojacking.

• Don't Fall for Phishing Emails and Messages: These days, cryptojacking mostly occurs through tabs in your web browser. That does not imply it cannot occur in other ways, such as when malware compromises your system's security. This often occurs through malicious links in phishing emails, therefore never click on links in unsolicited emails.

• Use a Firewall that is Updated: This is especially critical if your device is part of a bigger network that has a collective firewall. If you suspect a webpage contains a cryptomining script, it is crucial that the network firewall is updated to prevent you and everyone else in the network from accessing the page over the web. This will prevent bitcoin miners from using your network's resources without your awareness.

Best Practice

Zenarmor next-generation firewall is the most effective network security solution to prevent cryptojacking attacks by blocking ads. You can quickly install Zenarmor on your open-source firewall, like OPNsense, pfSense software and FreeBSD, or Linux-based systems such as Ubuntu, RHEL, CentOS, Debian, AlmaLinux and Rocky Linux.

You can use Zenarmor Free Edition to protect your valuable assets against not only cryptojacking but also phishing attacks, malware, spam with essential security features forever for free. Zenarmor offers enterprise-level security for home and small business networks by providing AI-based cyber threat intelligence. Advanced reporting, web content filtering and application control capabilities are other valuable features of Zenarmor available for free.

You can try Zenarmor Business edition to evaluate the enterprise level security, such as zero-day attack prevention.

Figure 1. Zenarmor Reports - Ads Blocking

Figure 2. How to block Ads on Zenarmor

Why Cryptojacking is Growing?

It is difficult to describe how cryptocurrencies gain monetary worth, but it is partially dependent on the law of supply and demand and the difficulty of acquiring the coin. There are a finite amount of Bitcoins that have not been entirely mined, for instance. Other aspects include the use of the money, the energy and equipment required to mine it, and more.

In recent years, the value of cryptocurrencies has changed for these and other reasons. In 2010, the price of a Bitcoin was less than 1 cent. Prior to the end of 2017, one Bitcoin was worth about $20,000 USD. As of June 2018, several cryptocurrencies have a maximum unit value of $6,750.83 USD.

In a sense, cryptojacking is a method for thieves to earn money for free with little effort. With only a few lines of code, cybercriminals are able to take control of another user's computer. Consequently, the victim must pay for the calculations and power required to mine bitcoin. The tokens are retained by the offenders.