If your PC is compromised with Trojan:Win32/Sirefef.AC, you may follow the procedure on this page to contain this threat. Remove the Trojan at once before it can bring more damage to the system.
Trojan:Win32/Sirefef.AC is a variant of Win32/Sirefef – a family of Trojan that may bring various hazards on the infected computer. One common thing about all variants is a rigid redirection of Internet search results to a different web site. This action aims to generate online revenue for its authors. When this Trojan infected a computer, user may experience a sudden slow-down on system performance. It consumes huge amount of system resources.
When Trojan:Win32/Sirefef.AC is executed on the computer. It will drop several files on Windows system folder, User Profile, and Temporary directory. These files are harmful and typically consist of random file name. It can also inject a code on legitimate Windows process to run itself while concealing its presence. This advance technique able to hide keep the Trojan undetected. It can evade even a powerful antivirus program.
Then, this Trojan will attempt to connect to a remote server to download other malware, probably another variant. Other type of Trojan:Win32/Sirefef.AC may be more dangerous that can cause permanent damage to an infected computer. Some essential files will be corrupted and some Windows services may be disabled. As a result of this grave harm, user may only remove the Trojan by reformatting the hard drive and reinstalling Windows.
Damage Level: Medium
Systems Affected: Windows 9x, 2000, XP, Windows Vista
How to Remove Trojan:Win32/Sirefef.AC
1. Download Microsoft Safety Scanner from this link and safe it on your desktop. This is a free tool from Microsoft that offer on-demand scanning. It helps remove computer infection such as malware, virus, and Trojan.
Note: If you have previous version of Microsoft Safety Scanner that is more than 10 days old, please disregard it. Download a new from the official web site. Every 10 days, Microsoft will release the latest edition of this tool with updated anti-virus definitions to ensure that it will detect even most recent malware threats.
2. Open your antivirus program and update the virus definition. Refer to your antivirus manual on how to initiate an update. Most antivirus software provides one-click process.
3. Restart Windows in Safe Mode.
– Turn off the computer. Then turn the power on, immediately press F8 on your keyboard right after a text appears on the screen.
– It will display a selection. Please choose Safe Mode and press Enter. Most threats like Trojan:Win32/Sirefef.AC will not load when you run Windows in this mode.
4. Once Windows starts in Safe Mode, open your antivirus program and run a full system scan and clean/delete all infected files. If it cannot perform clean/delete, better put the infected file into quarantine so that it will remain inaccessible.
5. Locate the file of Microsoft Safety Scanner (msert.exe) that you download earlier. Double-click to run the file.
6. When it shows End user license agreement, please accept and click Next to continue.
7. On Scan Type window, please select Full scan. The tool will scan the entire system. This is ideal to detect and remove all threats that are present on the computer.
8. Click Next to begin the scan. This process will take a while to finish. Please be patient and let MSS complete the scan procedure.
9. Once the scan operation ends, it will provide a report for identified threats. Please remove all the threats.
10. Reboot the computer and run another scan after Windows boots normally to make sure that Trojan:Win32/Sirefef.AC is gone.
Alternative Removal Method for Trojan:Win32/Sirefef.AC
Option 1 : Use Windows System Restore to return Windows to previous state
If Trojan:Win32/Sirefef.AC enters the computer, there is a big chance that Windows files, registry entries and other essential components are also infected. System Restore can reinstate clean system files by restoring the configuration to an earlier date. The method also replaces compromised files with a clean version. If you have a saved restore point before Trojan:Win32/Sirefef.AC infiltrates the PC, we highly encourage you to execute this procedure if none of the above works. You may proceed with Windows System Restore, click here to see the full procedure.