Know about Pdfiler.com pop-up
Some users are cheated by this page and download the file it offers. However they finally found that their browsers get slowed down and the performance get reduced. You should know that such a page is a malicious ad, which tries to mislead users to download its files to generate pay-per-downloaded revenue.
Seeing this pop-up means you got unwanted plugins and adware in your computer. They modify the browser settings and registry data to send the pop-up as soon as you run the infected browsers. It is quite necessary to clean up your browsers and unnecessary programs permanently.