Step 1: Close Safari
Before you do anything else, you should first close your browser. Normally, this shouldn’t be a problem but if for whatever reason Safari (or whatever other browser you might be using) won’t close, here’s what to do:
Open the Apple menu and select Force Quit. If this proves to be ineffective, use the Command Key + Option Key + Esc keyboard combination to open the Force Quit Applications box. There, select your browser and then Force Quit it.
Step 2: Activity Monitor
Open Finder and go to Applications > Utilities > Activity Monitor. Take a look at the processes and see if there are any suspicious entries there. If you see anything shady or anything with the name of the malware on it, Quit that process.
Step 3: Re-load Safari
Now, you will have to re-open your browser but without loading any of the previously opened pages. To do that, hold the Shift key and then click on the browser to open it.
If you still have issues with your browser not working properly, once again close Safari and disconnect your device from the Internet before you proceed with the next step.
Step 4: Cleaning your browser
Re-launch Safari while holding the Shift key and open its main menu. Go to Preferences and then open the Extensions tab. Look through the list of add-ons and uninstall anything that seems fishy or that might have the name of the malware on it. Generally, any extension that you do not recognize (or need) should be removed for good measure. If you aren’t certain about what to do, you can also uninstall all extensions and once the issue is fixed, re-install those that you might need in future.
Note that it is advisable you do this with any other browsers that you might be using. Remove suspicious extensions from them as well. Here is a brief explanation on how to do that for Chrome, IE and Firefox.
Go to the Main menu of the browser > More Tools > Extensions. Look at the extensions there and click on the trash can icon next to the ones that seem suspicious to uninstall them.
Open the Main Menu and select the Add-ons icon. Click on Extensions from the left panel and uninstall any Firefox extensions that might be unwanted or malware.
Go to Tools (top-right) > Manage Add-ons and check each type of add-ons (Toolbars and Extensions, Search Providers, Accelerators and In-private Filtering). Uninstall anything that you think could be an unwanted add-on.
Step 5: Cleaning website data
While still in Safari, go back to Preferences and this time select Privacy. Click on Remove all website data and confirm the removal. This will delete all your stored web data such as for example account credentials – you will need to manually type those once you want to access any of your web accounts.
Next, from Preferences, go to General and take a look at your Home Page – is it the one that you want it to be or the one that has been set by default. If it is not, change it to the one you like. Also, open the History menu and select Clean History.