Zeus Virus

Zeus, ZeuS, or Zbot is a Trojan horse malware package that runs on versions of Microsoft Windows. While it can be used to carry out many malicious and criminal tasks, it is often used to steal banking information by man-in-the-browser keystroke logging and form grabbing. 

Zeus is very difficult to detect even with up-to-date antivirus and other security software as it hides itself using stealth techniques.^[5] It is considered that this is the primary reason why the Zeus malware has become the largest botnet on the Internet: Damballa estimated that the malware infected 3.6 million PCs in the U.S. in 2009.^[6] Security experts are advising that businesses continue to offer training to users to teach them to not to click on hostile or suspicious links in emails or Web sites, and to keep antivirus protection up to date. Antivirus software does not claim to reliably prevent infection; for example Browser Protection says that it can prevent "some infection attempts".

                                                  

                                              

                                                           

Source...https://en.wikipedia.org/wiki/Zeus_(malware)