|Brief Description:||This type of Trojan users rootkit techniques to hide its presence on the infected computer.|
|Alias:||Trojan.Zeroaccess, Trojan: Win64/Sirefef.W, Trojan.Sirefef.FR, Win64/Sirefef.W, ZeroAccess|
|Source:||View on Microsoft website|
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.
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.
Procedures to Remove Trojan:Win64/Sirefef.Y
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 Trojan:Win64/Sirefef.Y. 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 Trojan:Win64/Sirefef.Y files with MalwareBytes Anti-Malware
To remove Trojan:Win64/Sirefef.Y, download Malwarebytes Anti-Malware. This tool is effective in getting rid of Trojans, viruses and malware.
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.
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 Trojan:Win64/Sirefef.Y are inside the computer, we must run another effective scanner. This time, use Junkware Removal Tool. No installation is necessary with this tool.
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."
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 Trojan:Win64/Sirefef.Y 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 Trojan:Win64/Sirefef.Y.
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 Trojan:Win64/Sirefef.Y, click on Reset button to bring back Internet Explorer's settings to their default condition.
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 Trojan:Win64/Sirefef.Y.
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 Trojan:Win64/Sirefef.Y.
2. Click Here to visit Qualys Browser Check web site.
3. Next, click on "Scan without installing lugin" link.
4. Click on Scan Now button to check and remove Trojan:Win64/Sirefef.Y 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 Trojan:Win64/Sirefef.Y 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 Trojan:Win64/Sirefef.Y 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'.
5. Please restart Google Chrome. New settings keep your browser safe while surfing the web.
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 Trojan:Win64/Sirefef.Y. 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.
4. Please restart Internet Explorer.
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 Trojan:Win64/Sirefef.Y. 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
Edge Browser - SmartScreen Filter
SmartScreen filter is a built-in feature in Microsoft Edge browser that can help you deter malicious programs such as Trojan:Win64/Sirefef.Y. 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.