At.yhs4.search.yahoo.com (Improved Guide)

Uninstall from Windows

1. Click Start → Control Panel → Programs and Features (if you are Windows XP user, click on Add/Remove Programs).
2. If you are Windows 10 / Windows 8 user, then right-click in the lower left corner of the screen. Once Quick Access Menu shows up, select Control Panel and Uninstall a Program.
3. Uninstall At.yhs4.search.yahoo.com and related programs
   Here, look for At.yhs4.search.yahoo.com or any other recently installed suspicious programs.
4. Uninstall them and click OK to save these changes.

Delete from macOS

1. If you are using OS X, click Go button at the top left of the screen and select Applications.
2. Wait until you see Applications folder and look for At.yhs4.search.yahoo.com or any other suspicious programs on it. Now right click on every of such entries and select Move to Trash.

Remove from Microsoft Edge

Delete unwanted extensions from MS Edge:

1. Select Menu (three horizontal dots at the top-right of the browser window) and pick Extensions.
2. From the list, pick the extension and click on the Gear icon.
3. Click Remove.

Clear cookies and other browser data:

1. Click on the Menu (three horizontal dots at the top-right of the browser window) and select Settings > Privacy, search, and services..
2. Under Clear browsing data, pick Choose what to clear.
3. Select Cookies and other site data and Cached images and files. (apart from passwords, although you might want to include Media licenses as well, if applicable) and click on Clear.

Restore new tab and homepage settings:

1. Click the menu icon and choose Settings.
2. Then find On startup section.
3. Click Remove next to any suspicious startup page.

Reset MS Edge if the above steps did not work:

1. Press on Ctrl + Shift + Esc to open Task Manager.
2. Click on More details arrow at the bottom of the window.
3. Select Details tab.
4. Now scroll down and locate every entry with Microsoft Edge name in it. Right-click on each of them and select End Task to stop MS Edge from running.

Instructions for Chromium-based Edge

Delete extensions from MS Edge (Chromium):

1. Open Edge and click select Settings > Extensions.
2. Delete unwanted extensions by clicking Remove.

Clear cache and site data:

1. Click on Menu and go to Settings.
2. Select Privacy, search and services.
3. Under Clear browsing data, pick Choose what to clear.
4. Under Time range, pick All time.
5. Select Clear now.

Reset Chromium-based MS Edge:

1. Click on Menu and select Settings.
2. On the left side, pick Reset settings.
3. Select Restore settings to their default values.
4. Confirm with Reset.
5. This will disable extensions and reset startup pages but will not delete bookmarks, saved passwords, or browsing history.

Remove from Mozilla Firefox (FF)

Remove dangerous extensions:

1. Open Mozilla Firefox browser and click on the Menu (three horizontal lines at the top-right of the window).
2. Select Add-ons.
3. In here, select the unwanted extension and click Remove.

Reset the homepage:

1. Click three horizontal lines at the top right corner to open the menu.
2. Choose Settings.
3. Under Home, set your preferred homepage and new tab settings.

Clear cookies and site data:

1. Click Menu and pick Settings.
2. Go to Privacy & Security section.
3. Scroll down to locate Cookies and Site Data.
4. Click on Clear Data…
5. Select Cookies and Site Data and Temporary cached files and pages, then click Clear.

Reset Mozilla Firefox

If clearing the browser as explained above did not help, reset Mozilla Firefox:

1. Open Mozilla Firefox browser and click the Menu.
2. Go to Help and then choose Troubleshooting Information.
3. Under Give Firefox a tune up section, click on Refresh Firefox…
4. Once the pop-up shows up, confirm the action by pressing on Refresh Firefox.

Remove from Google Chrome

Delete malicious extensions from Google Chrome:

1. Open Google Chrome, click on the Menu (three vertical dots at the top-right corner) and select More tools > Extensions.
2. In the newly opened window, you will see all the installed extensions. Uninstall all suspicious extensions related to the unwanted program by clicking Remove.

Clear cache and web data from Chrome:

1. Click on Menu and pick Settings.
2. Under Privacy and security, select Clear browsing data.
3. Select Browsing history, Cookies and other site data, as well as Cached images and files.
4. Click Clear data.

Change your homepage:

1. Click menu and choose Settings.
2. Look for a suspicious site in the On startup section.
3. Click on Open a specific or set of pages and click on three dots to find the Remove option.

Reset Google Chrome:

If the previous methods did not help you, reset Google Chrome to eliminate all the unwanted components:

1. Click on Menu and select Settings.
2. In the Settings, scroll down and click Advanced.
3. Scroll down and locate Reset and clean up section.
4. Now click Restore settings to their original defaults.
5. Confirm with Reset settings.

Delete from Safari

1. Remove dangerous extensions
   Open Safari web browser and click on Safari in menu at the top left of the screen. Once you do this, select Preferences.
2. Here, select Extensions and look for At.yhs4.search.yahoo.com or other suspicious entries. Click on the Uninstall button to get rid each of them.
3. Reset Safari
   Open Safari browser and click on Safari in menu section at the top left of the screen. Here, select Reset Safari....
4. Now you will see a detailed dialog window filled with reset options. All of those options are usually checked, but you can specify which of them you want to reset. Click the Reset button to complete At.yhs4.search.yahoo.com removal process.