Mac Virus

JS:Cryptonight Virus Removal Win/Mac (Dec. 2019 Update)

Parasite may reinstall itself multiple times if you don't delete its core files. We recommend downloading ComboCleaner to scan for malicious programs installed with it. This may save you hours and cut down your time to about 15 minutes. 

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If you have been infected by a Trojan horse called JS:Cryptonight, then you have come to the right place and the following article is exactly what you will need to deal with the infection. Trojan Miners are among the most dangerous malware types and are easily the most widespread.

Nearly 3 in every 4 malware infections recently have been caused by this exact category, so it’s really no exaggeration that they’re littered across the internet. That’s also one of the reasons why they are so well-known even to people who are less than tech-savvy. However, even despite being so infamous, most users still have no clue of what to expect from an infection like this. That’s why the infection with JS:Cryptonight may as well have come as a genuine shock to you when you discovered it. Not knowing what the consequences of this Trojan’s presence on your Mac can also be very unsettling. That’s why we will aim to provide you with some basic knowledge about Trojans in general. And once you have read through the information that follows, you can proceed to our detailed removal guide below, which will aid you in locating and removing JS:Cryptonight.

What Trojans are capable of and how to protect your system in the future

A Trojan like the one you are currently dealing with now can have almost unlimited abilities of causing damage to your system, and you personally as well. This is perhaps one of the main reasons why viruses of this type are so common and why they make up the vast majority of all malware in general. In addition to that they’re incredibly stealthy and can remain hidden deep inside your system without showing even the slightest symptoms. But what you’re really interested in knowing is what JS:Cryptonight virus is specifically up to on your machine right now. And unfortunately, there’s no way of knowing that for sure, unless it reveals its malicious purpose on its own. That’s not something you want happening, though, and you’d best have it removed before you get to find out why it’s there.

What we can do, though, is tell you about some of the most popular reasons hackers and cybercriminals employ Trojans for. Perhaps topping the list of most common usages would be theft. A Trojan horse virus like JS:Cryptonight can easily be stealing data from your computer and transmitting it back to the hackers. This can be files from your computer or information obtained about your bank accounts, social media profiles, passwords, logins, etc. Or, if it’s a more sophisticated piece of malicious programming, your whole internet traffic can be hijacked and made to go through the hackers’ servers. That way they will gain unlimited access to absolutely everything you do online.

Alternatively, a virus of this type can also be set to spy on you, using perhaps similar means. For example, it can record your keystrokes or tap into your webcam or microphone. That way the hackers will not only know what you type into your computer, but they will be able to hear and see you as well. In addition, they can track your location and gain access to any kind of correspondence you lead and all of this can be done for the purpose of draining your accounts, impersonating you, perhaps even breaking into your home or workspace, etc. There are plenty of other possible usages, too. Resource exploitation, malware distribution, destruction, spamming – and that’s not even scratching the surface.

Therefore, you have before you no two very important tasks, and you need to take them both seriously. One is, obviously, the removal of JS:Cryptonight. You can do this manually with the help of the guide below, or you can also use the professional removal tool instead, which will do the job for you. And the second task you have is to eliminate any weaknesses your system has that JS:Cryptonight could have used as a means to infiltrate your Macintosh. And outdated system or even a program that’s never been updated on your computer is a good place to start. Be sure to always install updates manually as soon as they emerge, and be sure to also update your antivirus program. If you don’t have one at all, it would be a good idea to install a high quality one asap. Last but not least, practicing safe browsing habits and avoiding potential malware sources will also help in preventing any future Trojan horse or other virus attacks.


Name JS:Cryptonight
Type Trojan Miner
Danger Level Medium (Annoying and potentially dangerous for your hardware)
Symptoms Increased usage of system resources.
Distribution Method Torrents, insecure web locations, file-sharing sites, adult content websites, malicious online ads and fake system update requests
Detection Tool

JS:Cryptonight Virus Removal

If you have a Windows virus, continue with the guide below.

If you have a Mac virus, please use our How to remove Ads on Mac guide.


We get asked this a lot, so we are putting it here: Removing parasite manually may take hours and damage your system in the process. We recommend downloading ComboCleaner to see if it can detect parasite files for you.

Some of the steps will likely require you to exit the page. Bookmark it for later reference.

Reboot in Safe Mode (use this guide if you don’t know how to do it).



To remove parasite on your own, you may have to meddle with system files and registries. If you were to do this, you need to be extremely careful, because you may damage your system.

If you want to avoid the risk, we recommend downloading ComboCleaner
a professional malware removal tool.

More information on ComboCleaner, steps to uninstallEULA, and Privacy Policy.

Press CTRL + SHIFT + ESC at the same time and go to the Processes Tab (the “Details” Tab on Win 8 and 10). Try to determine which processes are dangerous. 


Right click on each of them and select Open File Location. Then scan the files with our free online virus scanner:

Drag and Drop Files Here to Scan
Maximum file size: 128MB.

This scanner is free and will always remain free for our website's users. You can find its full-page version at:

Scan Results

Virus Scanner Result

After you open their folder, end the processes that are infected, then delete their folders. 

Note: If you are sure something is part of the infection – delete it, even if the scanner doesn’t flag it. No anti-virus program can detect all infections. 


Hold together the Start Key and R. Type appwiz.cpl –> OK.


You are now in the Control Panel. Look for suspicious entries. Uninstall it/them.

Type msconfig in the search field and hit enter. A window will pop-up:


Startup —> Uncheck entries that have “Unknown” as Manufacturer or otherwise look suspicious.


Hold the Start Key and R –  copy + paste the following and click OK:

notepad %windir%/system32/Drivers/etc/hosts

A new file will open. If you are hacked, there will be a bunch of other IPs connected to you at the bottom. Look at the image below:

hosts_opt (1)

If there are suspicious IPs below “Localhost” – write to us in the comments.

Open the start menu and search for Network Connections (On Windows 10 you just write it after clicking the Windows button), press enter.

  1. Right-click on the Network Adapter you are using —> Properties —> Internet Protocol Version 4 (ICP/IP), click  Properties.
  2. The DNS line should be set to Obtain DNS server automatically. If it is not, set it yourself.
  3. Click on Advanced —> the DNS tab. Remove everything here (if there is something) —> OK.



  • After you complete this step, the threat will be gone from your browsers. Finish the next step as well or it may reappear on a system reboot.

Right click on the browser’s shortcut —> Properties.

NOTE: We are showing Google Chrome, but you can do this for Firefox and IE (or Edge).


Properties —–> Shortcut. In Target, remove everything after .exe.

ie9-10_512x512  Remove JS:Cryptonight from Internet Explorer:

Open IE, click  IE GEAR —–> Manage Add-ons.

pic 3

Find the threat —> Disable. Go to IE GEAR —–> Internet Options —> change the URL to whatever you use (if hijacked) —> Apply.

firefox-512 Remove JS:Cryptonight from Firefox:

Open Firefoxclick  mozilla menu  ——-> Add-ons —-> Extensions.

pic 6

Find the adware/malware —> Remove.
chrome-logo-transparent-backgroundRemove JS:Cryptonight from Chrome:

Close Chrome. Navigate to:

 C:/Users/!!!!USER NAME!!!!/AppData/Local/Google/Chrome/User Data. There is a Folder called “Default” inside:

Rename the Folder to Backup Default

Rename it to Backup Default. Restart Chrome.


To remove parasite on your own, you may have to meddle with system files and registries. If you were to do this, you need to be extremely careful, because you may damage your system.

If you want to avoid the risk, we recommend downloading SpyHunter
a professional malware removal tool.

More information on SpyHunter, steps to uninstallEULAThreat Assessment Criteria, and Privacy Policy.

Type Regedit in the windows search field and press Enter.

Inside, press CTRL and F together and type the threat’s Name. Right click and delete any entries you find with a similar name. If they don’t show up this way, go manually to these directories and delete/uninstall them:

  • HKEY_CURRENT_USER—-Software—–Random Directory. It could be any one of them – ask us if you can’t discern which ones are malicious.
    HKEY_CURRENT_USER—-Software—Microsoft—-Windows—CurrentVersion—Run– Random
    HKEY_CURRENT_USER—-Software—Microsoft—Internet Explorer—-Main—- Random

If the guide doesn’t help, download the anti-virus program we recommended or try our free online virus scanner. Also, you can always ask us in the comments for help!

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