Why my updated antivirus program is unable to remove Win32:Sirefef-AHF [Trj] completely from the system? Why the running speed of my PC is becoming extremely sluggish? Why am I detecting unwanted changes in the default settings? These days, I have got lots of PC related issues which has created havoc for me. I have tried several ways to remove the threat but none of the them was helpful. If you have any idea about Win32:Sirefef-AHF [Trj] then please suggest what should I do now?

What is Win32:Sirefef-AHF [Trj]?

Win32:Sirefef-AHF [Trj] is a very harmful trojan infection which slips into windows computer very secretly and without asking for any approval. It is introduced to gain full control over to the compromised machine and execute malicious code inside PC to run its evil processes. Win32:Sirefef-AHF [Trj] comes along with suspicious code and injects numerous infectious extensions as well as malicious programs into compromised machine. In such way, it get success in covering in large space of system resources and thus you won’t find any single space inside your computer so you can install any new software program. Upon infiltration, Win32:Sirefef-AHF [Trj] reduces performance speed of the affected computer and internet starts running very slower like never before. Once this happened, you will have to wait for too long time to open any web page on browser or execute even a single application program on computer.

Once Win32:Sirefef-AHF [Trj] gets infiltrated into your computer, it will modify your system registry and open a backdoor for downloading other malware such as adware, browser hijacker and other infection to harm your PC. It can consume your system to make it slow down. Moreover, it can block your antivirus and firewall after that you computer may be crashed down due to it. It can change your DNA setting as well as it can steal your sensitive information such as password, login ID and commercial information etc. It will keep your computer fully on dangerous as useless for you. So, you should delete Win32:Sirefef-AHF [Trj] completely as possible.

How Win32:Sirefef-AHF [Trj] Intrudes Into User PC:

Win32:Sirefef-AHF [Trj] usages lots of method to intrudes into the user System, some of them are as follows:-

Freeware software packages
Junk mail attachments
Pornographic sites
Infected media devices
Unauthenticated file sharing
Browsing suspicious links
System loophole etc.

Harmful Effects of Win32:Sirefef-AHF [Trj]:

Automatically modify System or browser settings
Add new files or registry into user System
Generates lots of annoying or irritating pop-up ads and advertisements
Allow hackers to steal user all personal and crucial information
Degrades System performance etc

Method 1: Remove Win32:Sirefef-AHF [Trj] by Using SpyHunter.

SpyHunter is a useful malware removal tool that detects and removes many malicious threats that several of the major brands can’t detect. This tool will be able to find out and delete Win32:Sirefef-AHF [Trj] and other related threats from your PC without much trouble. Now follow the steps below to automatically remove the Trojan horse:

Step 1: Download and install SpyHunter on your PC.

download spyhunter now

Step 2: Upon the installation, launch SpyHunter and perform a full system scan by clicking “Scan Computer Now”.

spyhunter-scan computer now

Step 3: Wait for the scan to complete. Then, you will be shown all detected threats on your PC.

spyhunter-fix threats

Step 4: To clean up all threats completely, click “Fix Threats” and restart your PC.

Method 2: How to manually get rid of Win32:Sirefef-AHF [Trj]?

Restart your computer in Safe Mode with Networking.

For Windows 8:

Reach the desktop on Windows 8 first.
Press Ctrl + Alt + Del keys together.
Open Switch User interface.

And then hold down the “Shift” key and click on “Shut down” button.
Select Restart option from the pop-up page.
From the next page to choose “Troubleshoot”.

Click on “Advanced Option” and choose “restart”.
Under Startup Settings, press F5/5 key to navigate to the Safe Mode with Networking.

Windows 7, XP and Vista:
Shut down the affected computer first.
Press F8 key repeatedly until Windows Advanced Option Menu loads.
Select the Safe Mode with Networking option by using the up and down arrow keys.
Hit Enter key to reach the desktop.

Step 2: Open Task Manager by tapping Alt+Ctrl+Del keys together. Move the mouse pointer to “Processes” tab. Detect the fake process created by the Win32:Sirefef-AHF [Trj] popup and click on “End processes” to terminate them.

You can skip this step if you do not find any file associated with Win32:Sirefef-AHF [Trj] popup.

Step 3: Uninstall Win32:Sirefef-AHF [Trj] popup programs from the Control Panel.

Remove Win32:Sirefef-AHF [Trj] popup For Windows 7| Vista

  • Click on Start menu and tap Control Panel.


  • Select “Programs” option and choose “Uninstall a Program”.


  • Detect all the malicious programs associated with Win32:Sirefef-AHF [Trj] popup and click on Uninstall button.


Steps to Delete Win32:Sirefef-AHF [Trj] popup From Windows 8

  • On the right edge of the screen, Click on Search button and type “Control Panel”. Click on search button.


  • From the search results, select Control Panel. Its Window will appear on the screen, click on Programs and Features option.


  • Identify the unknown programs and click on Uninstall button to get rid of Win32:Sirefef-AHF [Trj] popup permanently.


Steps to Delete Win32:Sirefef-AHF [Trj] popup From Windows 10

  • Click on Start button.


  • To show all the contents, you need to click on Settings option.


  • Tap System.


  • From the System menu, Choose Apps and Features option.


  • Find Win32:Sirefef-AHF [Trj] popup from the list.


  • Finally, Click on Uninstall button to protect the system from Win32:Sirefef-AHF [Trj] popup.


Step 4.Uninstall Win32:Sirefef-AHF [Trj] via System Restore.

System Restore is a utility which comes with Windows operating systems and helps computer users restore the system to a previous state and remove programs interfering with the operation of the computer. If you have created a system restore point prior to installing a program, then you can use System Restore to restore your system and completely eradicate the unwanted programs like Win32:Sirefef-AHF [Trj]. You should backup your personal files and data before doing a System Restore.


a. Close all files and programs that are open.

b. On the desktop, right click Computer and select Properties. The system window will display.

c. On the left side of the System window, click System protection. The System Properties window will display.

System protection

d. Click System Restore and the System Restore window will display.

system properties system restore

e. Select Choose a different restore point and click Next.

restore system files and settings

f. Select a date and time from the list and then click Next. You should know that all programs and drivers installed after the selected date and time may not work properly and may need to be re-installed.

choose a restore point

g. Click Finish when the “Confirm your restore point” window appears.

confirm your restore point

h. Click Yes to confirm again.

windows 7 restore finish confirm


Win32:Sirefef-AHF [Trj] is vicious and pesky computer Trojan virus. Once this virus installed on your computer, it may open a backdoor for other infections to get into your computer easily, such as other Trojans, adware, malware and spyware and so on. Lots of unwanted activities may be run automatically by this pesky infection. Your CPU may be occupied by a large extend by lots of unfamiliar stuff which is installed by the Trojan itself. Hence, your system performance will be degraded badly. Therefore, your computer may get stuck, crashed, while webpage or even blue screen after this virus’s installation. So, removing this infection from your computer is an urgent task once it is detected on your computer.