Can not stop pop ups etc, display color too intense not responding to system preference display commands what antivirus is used in macs

Question

My 13 inch mac book pro is overrun with popups in spite of setting security  section etc. I removed McAfee and used clsm then  avasti and my display is too intense not responding to system preference display commands I have Adobe Flas in computer but Media Downloader keeps popping up to install also sILVER LIGHT IS IN HD BUT NOT WORKING VERY NEW MAC USER

Answer 1

A
You may have installed one or more of the common types of ad-injection malware. Follow the instructions on this Apple Support page to remove it. It's been reported that some variants of the "VSearch" malware block access to the page. If that happens, start in safe mode by holding down the shift key at the startup chime, then try again.
Back up all data before making any changes.
One of the steps in the article is to remove malicious Safari extensions. Do the equivalent in the Chrome and Firefox browsers, if you use either of those. If Safari crashes on launch, skip that step and come back to it after you've done everything else.
If you don't find any of the files or extensions listed, or if removing them doesn't stop the ad injection, ask for further instructions.
Make sure you don't repeat the mistake that led you to install the malware. It may have come from an Internet cesspit such as "Softonic" or "CNET Download." Never visit either of those sites again. You might also have downloaded it from an ad in a page on some other site. The ad would probably have included a large green button labeled "Download" or "Download Now" in white letters. The button is designed to confuse people who intend to download something else on the same page. If you ever download a file that isn't obviously what you expected, delete it immediately.
Malware is also found on websites that traffic in pirated content such as video. If you, or anyone else who uses the computer, visit such sites and follow prompts to install software, you can expect more of the same, and worse, to follow. Never install any software that you downloaded from a bittorrent, or that was downloaded by someone else from an unknown source.
In the Security & Privacy pane of System Preferences, select the General tab. The radio button marked Anywhere  should not be selected. If it is, click the lock icon to unlock the settings, then select one of the other buttons. After that, don't ignore a warning that you are about to run or install an application from an unknown developer.
Still in System Preferences, open the App Store or Software Update pane and check the box marked
          Install system data files and security updates (OS X 10.10 or later)
or
          Download updates automatically (OS X 10.9 or earlier)
if it's not already checked.
B
"Avast" is the worst of the whole wretched lot of commercial "security" products for the Mac. Not only does it fail to protect you from any real danger, it may send personal data (such as web browsing history and the contents of email messages) back to the developer without your knowledge, give false warnings, destabilize and slow down the computer, expose you to network attack, and corrupt the network settings and the permissions of files in your home folder. Removing it may not repair all the damage.
Some versions of the product also inject advertising into web pages. In short, apart from the fine print in the license agreement, Avast is indistinguishable from malware, and is arguably worse than any known malware now in circulation.
Back up all data, then remove Avast according to the developer's instructions. Restart.
If you tried to remove Avast by dragging an application to the Trash, you'll have to reinstall it and then follow the instructions linked above.