The issue focused on Microsoft's Office desktop software and Internet Explorer browsers. Windows Vista Internet Explorer users could find malware embedded in websites they visited by downloading malware called JavaScript engines for bots that automated cyberattacks. Microsoft engineers noticed this malware running on PCs during testing of Internet Explorer 9. At the time, Microsoft stated it would remove it from Internet Explorer 9 after Microsoft delivered Internet Explorer 10 to customers. It wasn't until Microsoft launched Internet Explorer 10 last September that Microsoft updated Internet Explorer's Java browser plugin with security patches that addressed