MalwareTips Blog

Removing malware has never been easier!

  • Blogs
    • Adware
    • Browser Hijackers
    • Unwanted Programs
    • Ransomware
    • Rogue Software
    • Guides
    • Trojans
  • Forums
  • News
    • Security News
    • Technology News
  • Tutorials
  • Malware Help
    • Malware Removal Assistance For Windows
    • Malware Removal Assistance For Mobile
    • Malware Removal Assistance For Mac
  • Giveaways
    • Giveaways, Promotions and Contests
    • Discounts & Deals
    • MalwareTips Giveaways
  • Reviews
    • Video Reviews
    • Users Review
  • Malware Hub
    • Malware Vault (Samples)

How to remove Trojan:JS/Medfos.B malware (Virus Removal Guide)

Trojans By Stelian Pilici on November 22, 2014

Trojan:JS/Medfos.B is a malicious JavaScript file that redirects search queries when using websites such as AOL, Ask, Bing, Google and Yahoo to other website from which cyber criminals get some sort of revenue.
Medfos is a member of the Win32/Medfos family and got your computer, after you have visited an infected website which exploited a vulnerability from a Java or Adobe software and Medfos installed a file called chromeupdate.crx in your %LOCALAPPDATA% folder.

As part of its self-defense mechanism,once installed Medfos disguises itself as a legitimate Google Chrome or Firefox extension with the name ChromeUpdateManager 1.0 or Translate This 2.0, as show in the below images:

Trojan:JS/Medfos.B sole purpose is to generate revenue for its authors via pay-per-click advertising links and redirect traffic to affiliate sites, so we recommend that you remove this Trojan as soon as possible from your computer.

Files reported as Trojan:JS/Medfos.B may not necessarily be malicious. Should you be uncertain as to whether a file has been reported correctly, you can submit the affected file to https://www.virustotal.com/en/ to be scanned with multiple antivirus engines.
You should always pay attention when installing software because often, a software installer includes optional installs. Be very careful what you agree to install.
Always opt for the custom installation and deselect anything that is not familiar, especially optional software that you never wanted to download and install in the first place. It goes without saying that you should not install software that you don’t trust.

How to remove Trojan:JS/Medfos.B virus (Virus Removal Guide)

This malware removal guide may appear overwhelming due to the amount of the steps and numerous programs that are being used. We have only written it this way to provide clear, detailed, and easy to understand instructions that anyone can use to remove malware for free.
Please perform all the steps in the correct order. If you have any questions or doubt at any point, STOP and ask for our assistance.
  • To remove Trojan:JS/Medfos.B virus, follow these steps:

  • STEP 1: Use Zemana AntiMalware Portable to remove malware
  • STEP 2: Scan and clean your computer with Malwarebytes Anti-Malware
  • STEP 3: Double-check for malicious programs with HitmanPro

STEP 1: Use Zemana AntiMalware Portable to remove malware

Zemana AntiMalware Portable is a free utility that will scan your computer for the Trojan:JS/Medfos.B browser hijacker and other malicious programs.

  1. You can download Zemana AntiMalware Portable from the below link:
    ZEMANA ANTIMALWARE PORTABLE DOWNLOAD LINK (This link will open a new web page from where you can download “Zemana AntiMalware Portable”)
  2. Double-click on the file named “Zemana.AntiMalware.Portable” to perform a system scan with Zemana AntiMalware Free.
    Zemana AntiMalware portable
    You may be presented with a User Account Control dialog asking you if you want to run this program. If this happens, you should click “Yes” to allow Zemana AntiMalware to run.
    Zemana AntiMalware User Account Control
  3. When Zemana AntiMalware will start, click on the “Scan” button to perform a system scan.
    Zemana AntiMalware Free Scan
  4. Zemana AntiMalware will now scan your computer for malicious programs. This process can take up to 10 minutes.
    Zemana AntiMalware scanning for virus
  5. When Zemana has finished finished scanning it will show a screen that displays any malware that has been detected. To remove all the malicious files, click on the “Next” button.
    Zemana AntiMalware Removing Trojan:JS/Medfos.B Virus
    Zemana AntiMalware will now start to remove all the malicious programs from your computer. When the process is complete, you can close Zemana AntiMalware and continue with the rest of the instructions.

STEP 2: Scan and clean your computer with Malwarebytes Anti-Malware

Malwarebytes Anti-Malware is a powerful on-demand scanner which should remove the Trojan:JS/Medfos.B virus from your machine. It is important to note that Malwarebytes Anti-Malware will run alongside antivirus software without conflicts.

  1. You can download download Malwarebytes Anti-Malware from the below link.
    MALWAREBYTES ANTI-MALWARE DOWNLOAD LINK (This link open a new page from where you can download “Malwarebytes Anti-Malware”)
  2. When Malwarebytes has finished downloading, double-click on the “mb3-setup-consumer” file to install Malwarebytes Anti-Malware on your computer.
    Malwarebytes installer
    You may be presented with an User Account Control pop-up asking if you want to allow Malwarebytes to make changes to your device. If this happens, you should click “Yes” to continue with the installation.
    Malwarebytes User Account Control Prompt
  3. When the Malwarebytes installation begins, you will see the Malwarebytes Setup Wizard which will guide you through the installation process.
    Setup Malwarebytes installer
    To install Malwarebytes Anti-Malware on your machine, keep following the prompts by clicking the “Next” button.
    Completing the Malwarebytes Setup Wizard
  4. Once installed, Malwarebytes will automatically start and update the antivirus database. To start a system scan you can click on the “Scan Now” button.
    Perform a system scan with Malwarebytes
  5. Malwarebytes Anti-Malware will now start scanning your computer for malicious programs.
    This process can take a few minutes, so we suggest you do something else and periodically check on the status of the scan to see when it is finished.
    Malwarebytes scanning for malware
  6. When the scan has completed, you will be presented with a screen showing the malware infections that Malwarebytes Anti-Malware has detected.
    To remove the malicious programs that Malwarebytes has found, click on the “Quarantine Selected” button.
    Malwarebytes Quarantine Selected
  7. Malwarebytes Anti-Malware will now quarantine all the malicious files and registry keys that it has found.
    To complete the malware removal process, Malwarebytes may ask you to restart your computer.
    Malwarebytes removing malware from computer
    When the malware removal process is complete, you can close Malwarebytes Anti-Malware and continue with the rest of the instructions.

STEP 3: Double-check for malicious programs with HitmanPro

HitmanPro can find and remove malware, adware, bots, and other threats that even the best antivirus suite can oftentimes miss. HitmanPro is designed to run alongside your antivirus suite, firewall, and other security tools.

  1. You can download HitmanPro from the below link:
    HITMANPRO DOWNLOAD LINK (This link will open a new web page from where you can download “HitmanPro”)
  2. When HitmanPro has finished downloading, double-click on the “hitmanpro” file to install this program on your computer.
    HitmanPro icon
    You may be presented with an User Account Control pop-up asking if you want to allow HitmanPro to make changes to your device. If this happens, you should click “Yes” to continue with the installation.
    HitmanPro User Account Control Pop-up
  3. When the program starts you will be presented with the start screen as shown below. Now click on the Next button to continue with the scan process.
    HitmanPro setup process
  4. HitmanPro will now begin to scan your computer for malware.
    HitmanPro scanning for Trojan:JS/Medfos.B virus
  5. When it has finished it will display a list of all the malware that the program found as shown in the image below. Click on the “Next” button, to remove malware.
    HitmanPro detected malware
  6. Click on the “Activate free license” button to begin the free 30 days trial, and remove all the malicious files from your computer.
    Activate HitmanPro to remove malware
    When the process is complete, you can close HitmanPro and continue with the rest of the instructions.

Your computer should now be free of the Trojan:JS/Medfos.B virus. If you are still experiencing problems while trying to remove Trojan:JS/Medfos.B virus from your machine, you can ask for help in our Malware Removal Assistance forum.
Help other people by sharing this article
Share on TwitterShare on FacebookShare on WhatsAppShare on Google+

We love Malwarebytes and HitmanPro!

We really like the free versions of Malwarebytes and HitmanPro, and we love the Malwarebytes Anti-Malware Premium and HitmanPro.Alert features.

Malwarebytes logoMalwarebytes Anti-Malware Premium sits beside your traditional antivirus, filling in any gaps in its defenses, providing extra protection against sneakier security threats.

Malwarebytes Anti-Malware Premium Features

HitmanPro logoHitmanPro.Alert prevents good programs from being exploited, stops ransomware from running, and detects a host of different intruders by analyzing their behavior. HitmanPro.Alert will run alongside your current antivirus without any issues.

HitmanPro.Alert Features

« Remove Zivb8r7v.com virus (Malware Removal Guide)
How to remove PUP.Optional.Bestop (Removal Guide) »
You are here: Blogs > Trojans > How to remove Trojan:JS/Medfos.B malware (Virus Removal Guide)

Helping people since 2010

MalwareTips has been launched in 2010, and we pride ourselves on offering detailed, clear, and easy to understand guides that anyone can use to remove malware for free.

BE PART OF OUR COMMUNITY!

Our community has more than 44.000 registered members, and we'd love to have you as a member.

Join us and take part in our unbiased discussions among people of all different backgrounds about security and technology . Register Now (it's free)

Follow us

Stay up to date with the latest cyber threats by following us on our social media accounts. Follow us on Twitter Like us on Facebook Follow us on Google+

TIP: What is “malware”?

Malware - short for malicious software - is an umbrella term that refers to any software program deliberately created to perform an unauthorized and often harmful action.
Viruses, backdoors, keyloggers, spyware ,adware, rootkits, and trojans are just a few examples of what is considered malware.
A few years ago,it was once sufficient to call something a 'virus' or 'trojan horse', however today's infection methods and vectors evolved and the terms 'virus and trojan' no longer provided a satisfactory definition for all the types of rogue programs that exist.

TIP: Avoid malware like a pro!

Keep your software up-to-date. This is especially true for things like your operating system, security software and Web browser, but also holds true for just about any program that you frequently use. Viruses often take advantages of bugs or exploits in the code of these programs to propagate to new machines, and while the companies that make the programs are usually quick to fix the holes, those fixes only work if they have been downloaded to your computer.

It's also important to avoid taking actions that could put your computer at risk. These include opening unsolicited email attachments, visiting unknown websites or downloading software from untrustworthy websites or peer-to-peer file transfer networks.

Helpful Guides

  • How to fix “No Internet After Malware Removal” (Free Guide)
  • How to remove Web Browser Redirect Virus (Windows Help Guide)
  • Remove “Update Flash Player” or “Update Java” fake alerts (Help Guide)
  • Remove “Your personal files are encrypted” ransomware (Removal Guide)
  • Remove Adware and Pop-up Ads from STEAM (Virus Help Guide)
  • Remove Adware and Pop-up Ads from Windows 10 (Virus Help Guide)
  • Remove Pop-Up Ads, Adware & Redirects from Web Browser (Guide)
  • Remove Pop-up Ads, Adware, or Virus from Microsoft Edge (Help Guide)
  • Remove Pop-up Ads, Redirects, or Virus from Android Phone (Help Guide)
  • Remove Pop-up Ads, Redirects, or Virus from Apple Mac OS (Guide)
  • Remove Tech Support Scam Pop-up Virus (Call For Support Scam)
  • Remove Unwanted Toolbars from Web Browser (Virus Removal Guide)
  • How to keep Windows 100% malware free – 5 steps guide!
  • From where did my PC got infected?
  • How to remove a Trojan, Virus, Worm and Malware (Windows Help Guide)
  • Remove stubborn malware
  • 3 Easy ways to remove any Police Ransom Trojan
  • How to fix a computer that won’t boot (Complete Guide)
  • How to remove Potentially Unwanted Programs (PUP’s) from Windows

Reset browser to default settings

  • How to reset Google Chrome to Default Settings (2017 Help Guide)
  • How to reset Internet Explorer to Default Settings (2017 Help Guide)
  • How to reset Mozilla Firefox to Default Settings (2017 Help Guide)

Recent Posts

  • How to remove AutoFixer Pro 2018 (Virus Removal Guide)
  • How to remove 83inzv.com redirect (Virus Removal Guide)
  • How to remove iSearch Search redirect (Virus Removal Guide)
  • Remove Search.smartmediatabsearch.com redirect (Virus Removal Guide)
  • How to remove Stabers.club redirect (Virus Removal Guide)
  • Remove Search.searchjsfd.com redirect (Virus Removal Guide)
  • Remove Search.hyourpdfsconverternow2.com redirect (Virus Removal Guide)

Need help?

If you would like help with any of these fixes, you can ask for free malware removal support in the Malware Removal Assistance forum. In this support forum, a trained staff member will help you clean-up your device by using advanced tools. Never used a forum? Learn how.

Ask for help now

  • Adware
  • Browser Hijackers
  • Unwanted Programs
  • Rogue Software
  • Ransomware
  • Trojans
  • Guides

Helpful Links

  • Contact Us
  • Terms and Rules
  • We Use Cookies
  • Privacy Policy

Community

  • Meet the Staff Team
  • Our Community Guidelines
  • Welcome Guide

TIP

Without meaning to, you may click a link that installs malware on your computer. To keep your computer safe, only click links and downloads from sites that you trust. Don’t open any unknown file types, or download programs from pop-ups that appear in your browser.

Copyright @ 2010 - 2018 - All Rights Reserved