My Mac Mini/Yosemite is new. But it now has malwares and Mac Keeper keeps popping up even after uninstalling.. Who can help?

Question

Hi everyone,
My mac mini is new. I have a few issues with it.
But the most annoying is the malwares that infested it now. I have only been using it for about 3 weeks or so. Of course, I thought everything that popped up are safe to click and just standard to click. I don't know yet what's best. Either, I figure out how to remove these ads / malwares or I just thought of reformatting it and start anew with it.
What would you guys recommend and please include steps for me to follow. I'm no techy.
By the way, I do not see these extensions on my Finder files (Conduit, also known as Trovi, MyBrand, or Search Protect, etc.) As a matter of fact, my extensions folder is empty except for the Adblock and AdBlock Plus that I recently installed to kill the ads.  However, it worked but it didn't stop MacKeeper and Facebook ads from popping to a new window each time I click a link, or just a space on a safari)
On YouTube, when I watch a video, every second, the other videos are pushed down for as long as i watch, they are kept being pushed down. These are done by ads that are being stopped by the AB and ABP. yes, the ads do not appear. Just a white space forever adding up. Very frustrating. Please help.
Thanks in advance!

Answer 1

How to uninstall MacKeeper - updated
How to Remove MacKeeper
Helpful Links Regarding Malware Problems
If you are having an immediate problem with ads popping up see The Safe Mac » Adware Removal Guide, AdwareMedic, or Remove unwanted adware that displays pop-up ads and graphics on your Mac - Apple Support.
Open Safari, select Preferences from the Safari menu. Click on Extensions icon in the toolbar. Disable all Extensions. If this stops your problem, then re-enable them one by one until the problem returns. Now remove that extension as it is causing the problem.
The following comes from user stevejobsfan0123. I have made minor changes to adapt to this presentation.
Fix Some Browser Pop-ups That Take Over Safari.
Common pop-ups include a message saying the government has seized your computer and you must pay to have it released (often called "Moneypak"), or a phony message saying that your computer has been infected, and you need to call a tech support number (sometimes claiming to be Apple) to get it resolved. First, understand that these pop-ups are not caused by a virus and your computer has not been affected. This "hijack" is limited to your web browser. Also understand that these messages are scams, so do not pay any money, call the listed number, or provide any personal information. This article will outline the solution to dismiss the pop-up.
Quit Safari
Usually, these pop-ups will not go away by either clicking "OK" or "Cancel." Furthermore, several menus in the menu bar may become disabled and show in gray, including the option to quit Safari. You will likely have to force quit Safari. To do this, press Command + option + esc, select Safari, and press Force Quit.
Relaunch Safari
If you relaunch Safari, the page will reopen. To prevent this from happening, hold down the 'Shift' key while opening Safari. This will prevent windows from the last time Safari was running from reopening.
This will not work in all cases. The shift key must be held at the right time, and in some cases, even if done correctly, the window reappears. In these circumstances, after force quitting Safari, turn off Wi-Fi or disconnect Ethernet, depending on how you connect to the Internet. Then relaunch Safari normally. It will try to reload the malicious webpage, but without a connection, it won't be able to. Navigate away from that page by entering a different URL, i.e. www.apple.com, and trying to load it. Now you can reconnect to the Internet, and the page you entered will appear rather than the malicious one.
An excellent link to read is Tom Reed's Mac Malware Guide.
Also, visit The XLab FAQs and read Detecting and avoiding malware and spyware.
See these Apple articles:
  Mac OS X Snow Leopard and malware detection
  OS X Lion- Protect your Mac from malware
  OS X Mountain Lion- Protect your Mac from malware
  OS X Mavericks- Protect your Mac from malware
  About file quarantine in OS X
If you require anti-virus protection Thomas Reed recommends using ClamXAV. (Thank you to Thomas Reed for this recommendation.)
From user Joe Bailey comes this equally useful advice:
The facts are:
1. There is no anti-malware software that can detect 100% of the malware out there.
2. There is no anti-malware that can detect everything targeting the Mac.
3. The very best way to prevent the most attacks is for you as the user to be aware that
     the most successful malware attacks rely on very sophisticated social engineering
     techniques preying on human avarice, ****, and fear.
4. Internet popups saying the FBI, NSA, Microsoft, your ISP has detected malware on
    your computer is intended to entice you to install their malware thinking it is a
    protection against malware.
5. Some of the anti-malware products on the market are worse than the malware
    from which they purport to protect you.
6. Be cautious where you go on the internet.
7. Only download anything from sites you know are safe.
8. Avoid links you receive in email, always be suspicious even if you get something
    you think is from a friend, but you were not expecting.
9. If there is any question in your mind, then assume it is malware.