Do you see some strange ads and coupons brought by Offers4U when you visit some sites like Walmart, Amazon or Ebay? This means that your computer is infected with an adware program. The problem occurs after user installs some program downloaded online at various free software download sites. Many of such cost-free utilities are often by default bundled with a lot of potentially unwanted programs (PUPs). Some of these PUPs are just annoying when they pop up in browsers, whereas some of these extra programs are very dangerous and may compromise your security and infect your computer with serious computer…