Crypto miner on your PC: signs and detection methods

With the increasing popularity of cryptocurrencies, malicious actors actively utilize others’ computing power for digital asset mining. If you notice that your computer is running noticeably slower and the fan is whirring more than usual, it could be a warning sign. Let’s understand how to detect a miner on your device and protect yourself from such threats.

What happens when a virus-miner infiltrates the system?

Mining malware is not just a virus but a form of digital exploitation. When such a program gets onto your computer, it begins covertly using its processor and graphics card to solve mathematical problems necessary to confirm cryptocurrency transactions.

The difference from honest mining is that the user did not choose this activity voluntarily. The program installs without consent, runs in the background disguised as a system process, and transmits the computational results to cybercriminal servers.

Technically, this is called cryptojacking — a phenomenon where attackers redirect your device’s power into their own pockets.

Main symptoms of infection

How to tell if there’s a miner on your computer? Pay attention to the following changes:

Performance has significantly decreased. Even simple operations — opening a browser, launching a text editor — take more time. The system often “hangs” for several seconds.

Resources are maxed out. Even when idle, the CPU or GPU is loaded at 70-100%. This is visible in any system monitor.

Device overheats. The fan spins at maximum speed, making loud noise. The computer case or laptop bottom becomes hot to the touch.

Electricity bills have increased. If energy consumption suddenly spikes without apparent reason, consider it.

Unknown processes appear in Task Manager. These could be programs with suspicious names like “sysupdate.exe” or “proc64.exe” that actively consume resources.

Browser behaves unstable. New extensions appear on their own, tabs open automatically, download speeds drop.

These signs rarely appear all at once, but if you notice at least a few of them — it’s time for diagnostics.

Step-by-step guide: how to detect a miner

Step 1: Analyze active processes

Start with a simple method — see what is running on your computer right now.

Open Task Manager (Ctrl + Shift + Esc on Windows or “Activity Monitor” on macOS). Go to the “Processes” tab and sort by CPU usage in descending order.

Look for processes that:

• Take 30% or more of CPU resources without clear reason
• Have strange names, written in lowercase or with numbers
• Are launched by system accounts (which is suspicious for regular applications)
• Continue running even after reboot

Right-click on a suspicious process and select “Open file location.” If the file is in the Temp folder or another non-standard directory, that’s an even more alarming sign.

Step 2: Run a full antivirus scan

Specialized software is your main ally in fighting malware. Choose one of the trusted options:

Kaspersky — detects cryptojacking with high accuracy.

Malwarebytes — specifically targets hidden threats and works more effectively against miners than traditional antiviruses.

Bitdefender — lightweight, fast, does not freeze the system during scan.

Install the program, update virus definitions to the latest version, then run a full system scan. This may take from 30 minutes to several hours depending on data volume.

After completion, check quarantine — it will list detected threats. If you see “Trojan.CoinMiner” or similar names, it confirms the presence of malware. Click delete and then restart your computer.

Step 3: Check startup items

Most miner viruses automatically launch when the computer starts. Remove them from there.

On Windows, press Win + R, type “msconfig” and open the “Startup” tab. Carefully review the list and disable all programs you did not install yourself.

On Mac, open “System Preferences,” then “Users & Groups.” Select your account and go to “Login Items.” Remove unfamiliar applications from this list.

A sign of a problem is if there are programs with strange names or from unknown developers in startup.

Step 4: Check your browser

Web mining is one of the most common infection methods. To detect a miner via browser:

Visit the extension management pages (in Chrome — “Settings” → “Extensions,” in Firefox — “Add-ons”). Remove all plugins you don’t remember installing.

Clear cache and cookies — malicious scripts are often embedded there. It’s recommended to do this regularly.

Install ad blockers and miner-blocking extensions — MinerBlock, uBlock Origin, or similar tools help prevent mining scripts from running on websites.

If your browser has become noticeably slower even on lightweight sites, it could indicate a hidden miner.

Step 5: Use advanced tools

For users ready for deeper analysis:

Process Explorer (download from the official Microsoft site) shows detailed info about each process. Run the program, find a high-load process, right-click and select “Check online” — the system will show what is known about this application.

Resource Monitor (built into Windows) allows real-time resource tracking and shows which process consumes the most energy.

Wireshark analyzes network traffic. Miners constantly send data to remote servers — Wireshark can help identify suspicious network connections.

Additional verification methods

If basic methods reveal nothing but performance issues persist:

Monitor network activity. Open Command Prompt (Win + R → “cmd”), type “netstat -ano” and analyze the connection list. Miners usually connect to known mining pools — search online for IP addresses your computer connects to.

Track temperatures. Use HWMonitor or MSI Afterburner. If idle CPU temperature exceeds 50°C, it’s abnormal and may indicate background activity.

Check the filesystem. Miners often store files in Temp, AppData, or Program Files folders. Use file system search to find unknown executable files with recent creation dates.

How does a virus-miner get onto your computer?

Understanding infection sources helps you avoid future problems:

• Pirated software and cracks — downloading licensed software from dubious sites often comes with malware installation.
• Phishing — malicious links in emails, messengers, and social networks.
• Operating system vulnerabilities — outdated Windows or macOS versions with unpatched bugs.
• Visiting infected sites — some web resources contain scripts that attempt to load miners onto your device.
• Torrents and pirated materials — a common source of infection.

Removing the miner

If you find malware, act as follows:

End the suspicious process in Task Manager (right-click → “End task”).

Locate the file path via process properties and delete it manually. If the system prevents deletion, reboot into Safe Mode.

Run the antivirus again to check for remnants.

Use CCleaner to remove temporary files and registry entries related to the malware.

In extreme cases, if the miner is deeply integrated into the system, reinstall the operating system.

Prevention: how to avoid infection

Prevention is much more effective than treatment:

• Install a reliable antivirus and update its definitions weekly.
• Download programs only from official developer sites.
• Use a VPN when visiting suspicious resources.
• Regularly update your OS and all installed software.
• Disable JavaScript on sites you do not trust.
• Avoid clicking on unknown links.
• Use password managers and enable two-factor authentication.

Conclusion

The ability to detect a miner on your computer in time is an important skill in the digital age. Mining viruses are becoming more sophisticated, but they leave traces: slow operation, increased resource load, unusual processes.

By following our guide, you can both check your computer for miners and protect yourself from future infections. Don’t delay the check if you notice early signs — the sooner you detect a miner, the less damage it can cause.

Use a combination of methods: Task Manager for initial analysis, antivirus software for detection, specialized tools for in-depth investigation. Protect your device and stay safe in the digital world.