 The popularity of Microsoft Security Essentials has led to the appearance of malware abusing its name . In February 2010 , a rogue security package calling itself " Security Essentials 2010 " appeared on the Internet . Designated <unk> : Win32 / <unk> by Microsoft , it bears no visual resemblance to the Microsoft product . It reappeared in November 2010 , this time calling itself " Microsoft Security Essentials 2011 " . A more dangerous rogue appeared in August 2010 . Designated Rogue : Win32 / <unk> or Unknown Win32 / Trojan , it closely resembles Microsoft Security Essentials and uses sophisticated social engineering to deceive users and infect their systems , under the guise of five different fictional anti @-@ malware products . It also terminates and prevents the launch of 156 different programs , including Registry Editor , Windows Command Prompt , Internet Explorer , Mozilla Firefox , Opera , Safari and Google Chrome . 
