The MacKeeper pop-up appear in your browser, the pop-ups might happen in Google Chrome or Mozilla Firefox or Safari at Mac OSX. This MacKeeper pop-up is caused by malicious software known as PUPs (Potentially Unwanted Program) or PUAs (Potentially Unwanted Application) also known as adware.
The adware causes pop-ups to promote ads thru a specific website and will pop-up if you click a blue, red or green underlined link or click in the middle of a website. The pop-ups are often based on keywords that are found on the website that you are visiting at the moment when the pop-up occurs.
The pop-up from MacKeeper is simply used to promote services or malicious software on your computer. Most of the pop-ups are for revenue, from services that are promoted by adware or potentially unwanted programs. The pop-ups might also offer a update for Java, the Adobe Flash Player or a Media Player update, which are obviously scams to install more unwanted software.
It is recommended to always read the Terms and Agreements and EULA’s before installing software on your computer.
Do never click to fast thru the installation process “Next” or “OK” button of software as you will agree to software you might not want to install. If the installer “Download Client” offers a Advanced or Custom option button, click it to find out if there is any other malicious software offered and installed during the installation process.