Rootkit.MBR.Vrabber.A is a terrible cyber threat carved by hackers obviously to make money and guess how! Yeah you are absolutely right; by hacking and obtaining other's financial information by stealing it from their computer systems without user consent or knowledge. This is actually a rootkit infection which is dangerous itself and can cause extreme damage to whatever computer it attacks be it vulnerable or security protected. This program being a rootkit is also used by other malwares because it helps them to hide in the memory and go undetected and do their sort of dirty work what they are supposed to. Rootkit.MBR.Vrabber.A changes many of your default settings, damages MBR ( a crucial part of any system responsible for OS upload at the time of reboot). Moreover, it also opens backdoor to let hackers have a bird's eye view of your data.
This rootkit infection in no way is good for your PC health and hence Rootkit.MBR.Vrabber.A must be removed ASAP.