JS.Downloader Trojan - How to remove

JS.Downloader is a detection Trojans based on Javascript, that is a language that is run in browsers and used to make page more interactive. The language might be used for harmfull purposes as well. Such Trojans have been known for years but keep infecting tons of online users to this day. The most obvious sign that you have been attacked by the JS.Downloader Trojan is your antivirus alert messages, but also slower browser and system, crashing programs, errors, frequent requests for updates and suspicious applications that you have not installed yourself. The downloader part means that computer parasite tries to infect PC with other malware, which can be both JS based and other types.

If you notice any of these signs, this means it is time to change your antivirus and fully clean your system in order to prevent any sensitive data leaking and consequential full computer destruction/file encryption. You may have heard about the similar kind of malware XMRig, CoinHive, LokiBot or SmokeLoader. It is best and easiest to remove JS.Downloader Trojan at the beginning of the infection, because then it is not so persistent and still has not managed to communicate with crooks which give future malicious directions and plans. Although it may be a tough cookie to deal with, 2-viruses team has prepared some easy to follow guidelines to help you get rid of JS.Downloader and its variants once and for all, so keep reading.

What is JS.Downloader Trojan

As you can tell from the name JS.Downloader is a Trojan type of malware, and as the story goes, it pretends to be a regular innocent file, but truly there is a malicious virus inside, which will compromise the system once it safely gets in. JS.Downloader does not describe just one Trojan, but refer to a whole family of malware that might have slightly different names, but behaves pretty much the same. Most of the antivirus software that reports such Trojan infections are AVG and Avast. Although these antivirus programs are not the most trustworthy when it comes to cyber protection because of the frequent False-positive reports, other reliable security products like Kaspersky detect JS.Downloader variants once in a while as well.

First JS.Downloader was noticed around 2003 October and since then been altered and changed names plenty of times. Most famous variants of JS.Downloader Trojan family are: JS.Downloader.Agent, Trojan.Downloader.JS.Agent, JS/Downloader, JS:downloader, JS.Downloader!gen33, JS.Downloader!gen36, JS:Downloader-DEF, JS/Downloader-tr, JS:Downloader-ZY, JS:Downloader-EOY , JS/Downloader.IOK , Trojan-Downloader.JS.Agent.hdm, JS/Downloader, Troj/JSDldr-AT. These are the names that you might see on your antivirus report if you really have been infected by this Javascript using Trojan.

Once Trojan.Downloader.JS.Agent enters the system it creates the files named %System%.exe, %temp%wininet.dll and then makes changes in the Windows Registry, modifying and adding new keys. This allows to use computers security loopholes and use remote host to connect with the hacker, find the location of the compromised machine, fake a digital certificate, gather and send recorded info to crooks, give infection updates to the developers, download and launch files, connect to the internet without asking for the victim’s permission and stay persistent no matter how many times user will restart the system.

The most # will be Browser slowing down significantly, programs crashing and freezing often, Windows loading up really slow, an antivirus showing virus alerts, but won’t find anything during the scan or won’t be able to clean it, a lot of errors. Meanwhile the JS.Downloader Trojan the will be stealing personal data, taking screenshots of infected computer and pages that include your logins, passwords, credentials, credit card information and downloading more malicious software like ransomware, adware and etc.

How does is JS Downloader Trojan infect systems

We know that JS Downloader is infecting only Windows operating systems and mostly doing it via targeted, Socially engineered emails. These special messages include hyperlinks or attachments that look like the regular picture (.jpg), video (.mp4, .flv, .avi), document (.doc, .pdf) files but actually they are executables, which after a click will start the installation of the virus. Because JS.Downloader is a javascript based virus, once the victim opens the attachment only a random string of characters will be seen that will not mean much to those who are not working in the IT sector.

What is more, some users have reported that they have been infected with the JS Downloader agent after visiting certain shady websites and also after downloading some suspicious software like Interstat. This scenario may be possible because of the bundling. Also, some people noticed that Fareit and Cryptowall were downloaded to their computers after their antivirus found JS Downloader.

How to get rid of the JS Downloader Trojan

The best cure is prevention, therefore following Safe browsing tips and recognizing spam is a good way to start for the JS Downloader Trojan free system. On the other hand, this Trojan family cannot be always prevented just with the help of precaution. As you may have heard, this month Alaskan town suffered from a multi-vectored attack which was also initiated by the Trojan virus, which despite the security measures managed to get in and compromise the network.

In such cases we recommend users to invest into a reliable anti-spyware tool like or Spyhunter that have been in the cyber business for years earning their name and trust amongst the malware specialists. While there are plenty of Fake antiviruses, these seem to be trustworthy, approved by specialists, sophisticated and resourceful even during the most persistent attacks.

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