Trojan:Win32/Popureb.A is a trojan that modifies the hard disk's MBR (Master Boot Record). It changes Internet Explorer's start page and also displays unwanted advertisements.
Trojan:Win32/Popureb.B is a trojan that displays advertisements, and modifies the affected user's Internet Explorer start page.
Trojan:DOS/Popureb.A is a detection for a malformed MBR (Master Boot Record) generated by Trojan:Win32/Popureb.A. It loads the encrypted malicious code and stores it as disk sectors when the affected computer boots.
VirTool:WinNT/Popureb.A is a component of Win32/Popureb. It uses a low level disk driver hook to prevent a malicious Master Boot Record (MBR) and other malicious data stored as disk sectors from being changed.