Cryptojacking

What is cryptojacking?

Cryptojacking is a form of cyberattack in which criminals use the computing power of a device – for example a computer, smartphone or server – to mine cryptocurrencies without being noticed. The term is made up of “cryptocurrency” and “hijacking”. The aim of the attackers is to hijack computing resources in order to mine cryptocurrencies without bearing the costs of hardware or energy. In contrast to other cyberattacks in which data or financial information is stolen, cryptojacking involves the theft of computing power.

How does cryptojacking work?

Cryptojacking works by injecting malware or malicious code into the target system. This happens in two primary ways:

• Browser-based cryptojacking: The malicious code is embedded in a website. When a user visits the website, JavaScript code is executed that uses the computer’s processing power to mine cryptocurrencies. As soon as the user leaves the website, the mining process usually ends.
• Device-based cryptojacking: Here, malware is installed on the device itself, which runs continuously in the background and makes resources available. This malware can enter the system by downloading infected files, through phishing emails or via security vulnerabilities in operating systems and software.

The attack often goes unnoticed, as the attackers usually do not attempt to noticeably impair the user experience – the aim is to keep the unlawful use undetected for as long as possible.

How can I tell if my device is being used for cryptojacking?

Symptoms of a cryptojacking attack can be subtle, but there are signs that indicate the unauthorized use of computing power:

• Slower performance: The device responds more slowly than usual, especially when performing simple tasks such as surfing the Internet or starting programs.
• Increased CPU utilization: The CPU (central processing unit) operates at an extremely high level, even if no resource-intensive applications are running.
• Overheating: Devices such as laptops, PCs and smartphones become excessively warm because the CPU is constantly under load.
• Fan activity: The fans are constantly working at full speed to cool the device, even when it is not under heavy use.
• Increased power consumption: A sharp increase in the electricity bill or a faster discharge of batteries, as mining places intensive demands on the hardware.

Which devices are susceptible to cryptojacking?

In principle, any internet-enabled device can be vulnerable to cryptojacking. This includes the following devices:

• Computers (desktop and laptop): The most common targets, especially Windows and Linux systems that are not regularly updated.
• Smartphones and tablets: Android and iOS devices can be affected by malicious apps or compromised websites.
• Servers: Poorly secured cloud servers or older servers without the latest security updates are particularly vulnerable.
• IoT devices (Internet of Things): Smart devices such as televisions, thermostats, cameras or routers often offer inadequate protection and are therefore easy targets for cryptojackers.

How can I protect my device from cryptojacking?

The following measures should be taken to protect devices from cryptojacking:

• Adblockers and script blockers: Tools such as “NoScript” or “uBlock Origin” can prevent malicious scripts from being executed in browsers.
• Antivirus programs: An up-to-date and comprehensive security solution can detect and remove malware designed for cryptojacking.
• Browser extensions against cryptojacking: Extensions such as “MinerBlock” or “No Coin” prevent mining scripts from being executed in the browser.
• Regular updates: Operating systems, browsers and software should always be kept up to date in order to close known security gaps.
• Strong passwords: Secure passwords and the activation of two-factor authentication (2FA) prevent attackers from easily accessing devices.
• System performance monitoring: Regular monitoring of CPU and RAM utilization can help to detect unusual activities at an early stage.

Is cryptojacking illegal?

Yes, cryptojacking is illegal. As it is carried out without the knowledge and consent of the device owner, it is an unlawful use of resources and therefore falls under hacking and misuse of IT systems. In many countries, the use of cryptojacking can have legal consequences as it is considered a cybercrime. The illegal use of other people’s hardware without their consent is a clear violation of IT security laws.

How do I remove cryptojacking malware?

The removal of cryptojacking malware often requires several steps:

• Perform a system scan: Use an up-to-date antivirus program or a special malware scanner to search for malicious software.
• Empty browser caches and check extensions: Since cryptojacking often takes place via the browser, browser data should be deleted and suspicious extensions deactivated or removed.
• Uninstall suspicious programs: Check the installed programs and uninstall unknown or suspicious applications.
• Update the operating system: Installing the latest security updates can help close known vulnerabilities that have been used to get cryptojacking malware onto the device.
• System monitoring: After removal, the system should be monitored to ensure that no new anomalies occur.

What impact does cryptojacking have on my device?

Cryptojacking has several negative effects on a device:

• Drop in performance: The permanent use of computing power through cryptojacking leads to a noticeable drop in system speed and performance.
• Increased electricity costs: As the device works around the clock, energy costs also increase. The battery of smartphones and laptops drains faster.
• Overheating and hardware wear: The constant high load can cause the device to overheat and wear out more quickly. The fan, CPU and graphics card in particular are subject to heavy strain.
• Security risks: A device that has been the victim of cryptojacking may also be vulnerable to other cyberattacks, as vulnerabilities or malware may be present.

Which cryptocurrencies are mined in cryptojacking?

The most commonly mined cryptocurrency through cryptojacking is Monero (XMR). Monero is particularly popular as it focuses on anonymity and is designed to be mined efficiently on conventional CPUs and GPUs without the need for specialized hardware (such as ASICs). Other cryptocurrencies such as Zcash or Ethereum could also be the target of cryptojacking, however Monero is the preferred choice due to its low hardware requirements and focus on privacy.

Which protection software helps best against cryptojacking?

There are several tools and programs that have been developed specifically to combat cryptojacking:

• NoCoin: A browser extension that prevents mining scripts from being executed.
• MinerBlock: Blocks crypto-mining scripts both on websites and in background processes.
• Adblockers like uBlock Origin: Many mining scripts are embedded via advertising. Adblockers such as uBlock Origin can help to block these.
• Antivirus software with cryptojacking protection: Some antivirus programs such as Kaspersky, Bitdefender and Malwarebytes offer specific protection functions against cryptojacking.

Regular security measures and a critical approach to unknown downloads and websites are also essential to protect yourself effectively against cryptojacking.

Zurück zur Übersicht des Glossars