Remove Win32/Sirefef.FB.Gen

Threat Summary

Type: Trojan
Brief Description:This type of Trojan users rootkit techniques to hide its presence on the infected computer.


Win32/Sirefef.FB.Gen is a module of Win32/Sirefef – a multi-part group of Trojan that controls infected user’s Internet browsing by redirecting search result to unknown web sites. It also tries to produce pay-per-click profit for its authors. Basically, main goal of Win32/Sirefef.FB.Gen is to drive traffic to a web site that can generate revenue via online ads. This family of rootkit Trojan covers several variants that act upon different functions. This includes downloading other malware, hiding its presence, and executing other payload.

With Win32/Sirefef.FB.Gen advanced covert mechanism, it can deter antivirus detection. In some instances, if security program is weak, the Trojan can easily stop the service that belongs to security software.Win32/Sirefef.FB.Gen is so dangerous that it can control programs that may run on the affected computer. Most often, it will not allow security programs to initiate. It will block the process and issue a warning that the file is compromised. This threat may create certain lasting changes on the system that will require user to reformat the operating system in order to make the computer usable once more.

Removal of Win32/Sirefef.FB.Gen will depend on how serious the damage is. It can be taken away from the computer using virus scan. However, at some point, victim’s resort to reformatting of Windows just to delete this Trojan from the computer. Please use the guide below to get rid of this threat. If this will not work, it is better to consult technical expert first before reformatting the infected computer.

What are the Symptoms of Win32/Sirefef.FB.Gen Infection?

When this Trojan enters the computer, your installed antivirus program will display an alert. So far this is the obvious and visible symptoms of the Trojan.

Win32/Sirefef.FB.Gen Detection by ESET

Procedures to Remove Win32/Sirefef.FB.Gen

Removal steps on this page will help you get rid of the threat effectively using tools and virus scanners. Please make sure that you will carry out the guide in exact order.

Procedure 1: Scan Computer in Safe Mode Using Installed Anti-virus Program

1. When troubleshooting a PC, one common step is to boot operating system into Safe Mode with Networking. The same approach will be used in the removal of Win32/Sirefef.FB.Gen. Please execute instructions based on your Windows OS version.

Start Windows 8 / Windows 10 in Safe Mode with Networking

- Close all running programs on your computer because we will need to restart Windows on this procedure.
- Press and Hold Shift key on your keyboard while clicking on Restart.
- You will then be presented with Troubleshooting Options.
- Click on Troubleshoot icon.
- Then, Click on Advanced Options icon.
- Select Startup Settings icon and then, Click on Restart button.
- When Windows restarts, it will prompt to choose number from the list of options. Press the number on your keyboard that corresponds to Safe Mode with Networking, commonly number 5.
- Once in Safe Mode, please proceed to the next step which is running a virus scan on the computer.

Start in Safe Mode with Networking (Windows XP / Vista / 7 Instruction)

- Please restart the computer and just before Windows start, press F8 on your keyboard repeatedly. You will be presented with Advanced Options Menu.
- From the selections, choose Safe Mode with Networking. Please use keyboard's arrow up/down to navigate between selections and press Enter to proceed.


2. Once your Windows is running in Safe Mode, open your installed anti-virus programs and update it to the most recent version by automatically downloading necessary updates.

3. Thoroughly scan the computer and remove all identified threats. Do not restart or turn off the computer after the scan process. You still need to run another scan. Please follow the next procedure.

Procedure 2: Scan and remove Win32/Sirefef.FB.Gen files with MalwareBytes Anti-Malware

To remove Win32/Sirefef.FB.Gen, download Malwarebytes Anti-Malware. This tool is effective in getting rid of Trojans, viruses and malware.

Download Removal Tool

1. After downloading, please install the program using the default settings.

2. At the end of the installation, please make sure that it will download necessary updates.

3. Once update has completed, MBAM will launch.

MBAM Scanner

4. Select SCAN from the top menu. Then, click on Threat Scan (Recommended) section.

5. Click on Start Scan to thoroughly scan the computer. Remove all threats detected by this anti-malware program after the process.

Procedure 3: Run extra scan with Junkware Removal Tool

To make sure that no more malicious files linked to Win32/Sirefef.FB.Gen are inside the computer, we must run another effective scanner. This time, use Junkware Removal Tool. No installation is necessary with this tool.

Download JRT

1. Click the button above to start the download process. Save the file to your preferred location.

2. Junkware Removal Tool will close all running applications later. So, before executing the file, please Bookmark or Print this page. And then, close all programs.

3. Double-click the JRT.exe file to initiate the tool.

4. It will prompt you to "Press any key to continue."

JRT Scanner

5. Junkware Removal Tool will create a Restore Point and proceed with the scan. Please wait for the scan process to finish.

6. After scanning the computer, JRT will open a Notepad containing scan logs. It may have not find Win32/Sirefef.FB.Gen relevant entities, but it will surely delete any malicious items not found in the previous scans.

Procedure 4: Reset Affected Internet Browser

Reset browser settings of Google Chrome:

1. Open Google Chrome browser.

2. In the address bar, type this: chrome://settings/ and then, press Enter.

3. Navigate at the end of the page and click on Show advanced settings.

4. At the bottom of the page, click on Reset settings to remove all changes made by Win32/Sirefef.FB.Gen.

Reset Google Chrome

Reset Internet Explorer Settings:

1. Open Internet Explorer software.

2. Navigate to top menu and click Tools > Internet Options.

3. On Internet Options window, select Advanced tab.

4. In order to reverse modifications caused by Win32/Sirefef.FB.Gen, click on Reset button to bring back Internet Explorer's settings to their default condition.

Internet Explorer

Reset Firefox to its default state:

1. Open Mozilla Firefox program.

2. Navigate to top menu and Open Help Menu. Then, select on Troubleshooting Information.

3. Click on Refresh Firefox button to erase the effect of Win32/Sirefef.FB.Gen.

Reset Firefox

Procedure 5: Run Qualys Online Browser Check

Qualys Browser Check performs a security examination on your browser including installed plug-ins and add-ons. At the end of the scan, this tool will recommend on what to remove and give you steps to resolve any vulnerabilities found on the browser.

1. Open Internet browser application that is affected by Win32/Sirefef.FB.Gen.
2. Click Here to visit Qualys Browser Check web site.
3. Next, click on "Scan without installing lugin" link.

Online Browser Check

4. Click on Scan Now button to check and remove Win32/Sirefef.FB.Gen and any other malicious add-ons and extensions. You must read and accept "Service User Agreement" to continue.
5. After the scan, you will be presented with Browser Check Summary. Fix any issues and follow the recommendation on the result.

Protect your PC from Win32/Sirefef.FB.Gen or Similar Attack

Turn On Safe Browsing Features

Google Chrome's Protection from Dangerous Sites

With Google Chrome's Dangerous Site Protection feature, you will have lesser risks browsing the web. It will display a warning when the site you are trying to visit is suspicious, thus, you can prevent Win32/Sirefef.FB.Gen infection. To enable protection from dangerous sites, please do these steps:

1. Open Google Chrome.

2. In the address bar, type this: chrome://settings/ and then, Press Enter.

3. Once on the settings page, click on Show advanced settings... at the bottom of the page to see the rest of the Chrome setup.

4. Locate Privacy section and mark 'Protect you and your device from dangerous sites'.

Chrome Security Settings

5. Please restart Google Chrome. New settings keep your browser safe while surfing the web.

SEE MORE : Enable Google Chrome's protection from dangerous sites

Internet Explorer - Activate SmartScreen Filter

Internet Explorer versions 8 and 9 has this feature called SmartScreen Filter. It helps detect phishing web sites and protect you from downloading malicious programs including Win32/Sirefef.FB.Gen. To turn on SmartScreen Filter, follow these steps:

1. Please open Internet Explorer.

2. On top menu, select Tools (IE 9). For IE 8, please look for Safety menu.

3. Select SmartScreen Filter from the drop-down list and click on Turn on SmartScreen Filter.

IE SmartScreen Filter

4. Please restart Internet Explorer.

SEE MORE : Comprehensive steps to activate SmartScreen Filter

Mozilla Firefox - Block Attack Sites and Web Forgeries

Phishing and Malware Protection is a built-in feature on Firefox version 3 or later. It warns you when a page you are trying to visit contains phishing content or an attack site designed to drop threats such as Win32/Sirefef.FB.Gen. To help you keep safe while browsing the Internet using Firefox, please follow this guide:

1. Open Mozilla Firefox browser.

2. On top menu, click on Open Menu. Then select Options from the list.

3. Select Security and put a check mark on the following items:

  • Warn me when sites try to install add-ons
  • Block reported attack sites
  • Block reported web forgeries

Firefox Security Settings

Edge Browser - SmartScreen Filter

SmartScreen filter is a built-in feature in Microsoft Edge browser that can help you deter malicious programs such as Win32/Sirefef.FB.Gen. It can block malicious web sites and downloads.

1. Open Microsoft Edge browser.

2. Click on More Actions button located at top right corner of the screen.

3. Select Settings from the drop-down list.

4. Under Settings menu, go to Advanced Settings section and click on View Advanced Settings.

5. Scroll down to "help protect my PC from malicious sites and downloads with SmartScreen Filter". Turn it to ON.

6.You may now restart Microsoft Edge browser.

Edge SmartScreen Filter

One thought on “Remove Win32/Sirefef.FB.Gen

  1. Ipparxos says:

    These fake security system viruses are a real pain to get rid of. And many get by my real active antivirus program. You can try the removal tools if you want but many don’t work.This has worked every time I get one running XP. At least 8 times so far over the last 6 months and it is simple.This works every time.Shut off computer.Restart and as soon as welcome screen comes on go and run system restore to a time prior to infection (yesterday).You must start the system restore program before the virus loads so be quick.Once the virus loads it wont let you start the restore program.This has worked every time I get it.I gave up on all the removal tools posted here.Someone called me a moron for suggesting this. I wonder if they work for the removal tool Cos.?Of course one should restore to a clean setting.Run a complete scan after restore if you want and follow this if your restore point was not clean or go back to an earlier one.

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