By | June 14, 2012 | 8 Comments

Trojan:Win64/Sirefef.Y is a component of Win64/Sirefef family. A multi-component group of Trojans that manipulates infected computer’s Internet browsing activity. Commonly, it modifies the search result on victim’s PC and redirects it to Trojan location. It also hijacks Internet browser to generate pay-per-click advertising profit for its makers.

This family of Trojans where Trojan:Win64/Sirefef.Y belongs may perform various actions once it is executed on the computer. This includes updating itself, download and execution of other malware, or hiding other components. There are no typical symptoms for each variant. With regards to Trojan:Win64/Sirefef.Y, most affected users reports that the Trojan is capable of hijacking Internet browser, displaying of advertisements, and blocking access to some web sites.

When Trojan:Win64/Sirefef.Y is initiated, it will begin to alter system settings. It also targets the registry of Windows and input relevant entries. This action may bring the Trojan in front of the start-up process. Moreover, the Trojan will drop other components that can perform diverse actions not yet accomplished on the compromised PC. It will also attempt to establish a connection to a remote server and pull down other malware, not a member of this clan. Commonly, it downloads a backdoor Trojan that will allow a remote attacker to control the computer and carry out harmful actions.

Type Trojan
Sub-Type FakeAV
OS Affected Windows

What are the Symptoms of Trojan:Win64/Sirefef.Y Infection?

When this Trojan enters the computer, Microsoft Security Essentials will display an alert. If user tries to remove the infection, Windows will logoff instantly.

Detection of Trojan:Win64/Sirefef.Y

Follow these Procedures to Remove Trojan:Win64/Sirefef.Y

Procedure 1: Start Computer in Safe Mode

Restart your computer in Safe Mode with Networking

- After turning On the power of the computer, just before Windows start, press F8. This is a quick process, so you must press F8 button very timely. Failure to enter this mode will start Windows normally. In that case, you need to turn off the PC again and repeat the process.

- From the selections, choose Safe Mode with Networking. Please use keyboard's arrow up/down to navigate between selections and press Enter to proceed. Safe Mode boots slower than normal and your screen will be in low-resolution format. If it prompts you at boot-up, please proceed to Safe Mode. Loaded driver and processes are minimal so expect that other devices on the computer will not be available during this mode.

SafeMode Networking

Procedure 2: Scan and remove Trojan:Win64/Sirefef.Y files with MalwareBytes Anti-Malware

To remove Trojan:Win64/Sirefef.Y, download Malwarebytes Anti-Malware by clicking on the button below. This tool is effective in getting rid of Trojans, viruses and malware.

Download Trojan:Win64/Sirefef.Y 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. The tool will launch.
4. Thoroughly scan the computer and remove all threats detected by this anti-malware program.

Procedure 3: Run TrendMicro's Fake Antivirus Remover (ATTK) to check and delete any remnants of Trojan:Win64/Sirefef.Y.

As an added help to remove Trojan:Win64/Sirefef.Y, you can scan the computer with Fake Antivirus Removal Tool. This software is provided and distributed by TrendMicro. Follow this procedure to run a scan with this tool.

1. Download the package by clicking on the button below. This will launch a new browser window that contains further details about the tool.

FakeAVRemover Download Link

2. Save the file to a location on your hard drive.
3. Browse for the location of the file and double-click to run. If you are using Windows Vista or Windows 7, right-click on extracted file supportcustomizedpackage and click on Run as Administrator.

Run FakeAVRemover

4. When program launch, it will run a command prompt to initialize, prepare components, and update the program.
5. Next it will open the graphical user interface (GUI) of Anti-Threat Toolkit.

FakeAVRemover GUI

6. Click on Scan Now. This operation will scan all Trojan:Win64/Sirefef.Y files and processes in your computer and display a list of result for possible Fake Antivirus program and malware that needs to be removed.

FakeAVRemover Scan

7. Tick all items that are detected by the program, and then click Clean. The tool will start removing Trojan:Win64/Sirefef.Y components from the computer.
8. If it asked you to restart Windows, please do so.

Procedure 4: Remove Rootkit Trojan with Avast aswMBR

A Trojan often drops malware using an advance technology known as rootkit. It hides the installation of Trojan:Win64/Sirefef.Y from your anti-virus program and injects malicious code to running Windows processes. To complete the clean-up process, you also need to scan and remove rootkit Trojan.

1. Download aswMBR from Avast server. Save it to your computer.

Avast Rootkit Scanner

2. Double-click on the file aswMBR.exe to run the program.
3. If it prompts you to download the latest Avast! virus definition, please click Yes. This is necessary to identify most recent version of the Trojan as well as hidden files of Trojan:Win64/Sirefef.Y.

Updating aswMBR

4. Click on Scan button to start checking your computer for presence of rootkit Trojan and other viruses. It will display a message "Scan finished successfully" when done.

aswMBR Scan

5. Click Fix or FixMBR to start removing infection. If aswMBR contains the latest Avast! virus definition file, it will automatically clean infected files on your PC.

Protect your PC from Trojan:Win64/Sirefef.Y or Similar Attack

Turn On Security Features of your Internet Browser

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 files online. You may have avoided Trojan:Win64/Sirefef.Y virus if this has been active on your PC. 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

Google Chrome's Enable Phishing and Malware Protection

With Google Chrome's Phishing and Malware Detection feature, you will have lesser risks browsing the web. It will display a warning when the site you are trying to visit is suspicious. To enable Phishing and Malware Protection, please do these steps:

1. Open Google Chrome.
2. Click on the Customize and control Google Chrome (3-Bars Icon) located on top right corner of the browser.
3. Select Settings from the drop-down list.
4. Once on the settings page, click on Show advanced settings... at the bottom of the page to see the rest of the Chrome setup.
5. Locate Privacy section and mark 'Enable phishing and malware protection'.

Chrome Security Settings

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

SEE MORE : Enable Phishing and Malware Protection on Google Chrome

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 on the computer. 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 Tools. 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

Remove Trojan:Win64/Sirefef.Y & Protect Your Computer Now!

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8 thoughts on “Trojan:Win64/Sirefef.Y

  1. paraid2

    Nice procedure. It take out the Trojan from my laptop. In addition to this guide, I also run a scn of yorkyt from Panda Labs. It is a tool dedicated in removing Sirefef Trojans. It found no infected files, but it forces to overwrite some drivers.

  2. Unknown

    Thanks very much. I tried everything to remove this problem before installing these specific programs. With help of this guide my computer is good as new.

  3. Sweetie

    i can’t to delete the virus from my computer but, this article was useful, due to i could access to my data and doing a copy, thanks for your help.

  4. THANKYOU!!!

    Thanks a lot! COuldn’t get past the constant restarting until I goolgled the trojan using my phone and stumbled upon your AWESOME removal guide. Everything seems good now. Thanks again

  5. ML

    My PC restarts too soon to allow any of these to run or install. Can I run in dos mode?? Please help!

  6. dansben

    @ML. Does it restart in safe mode? If so, you last chance would be to scan the computer with Kaspersky Rescure Disk. This tool will boot your copmputer via USB drive.

  7. wizpsycho

    @ML You must disable Microsoft Antimalware Service … clicck run then msconfig then go in services tab and uncheck Mirosoft Antimalware Service it will stop the process who keep restating the computer.. worked for me today …

  8. Popper

    Yes, disable microsoft forefront security and your computer shouldn’t restart so quickly. It seems as if it disables safe-mode (a restart after a long hang into normal mode). So immediately at start-up open MSCONFIG and stop the service. Still trying to clean it up but at least you can browse the web for a solution and download the fixes.

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