This boot record is also named the Volume Boot Record and contains further instructions for booting up the operating system. The Boot Loader(or Partition Loader) looks in Partition Table for an active partition, usually that’s the partition containing the operating system and load the Boot Record which is located in the first sector of that partition(remember, the MBR is located in the first sector of hard disk) and has like the MBR, 512 bytes in size.The MBR is including also short error messages used in unsuccessful booting cases: “Invalid partition table”, “Error loading operating system” or “Missing operating system” The Master Boot Record with 512 bytes in size, is located in the first sector of the hard drive, cylinder 0, head 0, sector 1 and if it is valid(the last two bytes must be 55AAh) will contain a section with informations about hard disk partitions named partition table and another section with the Primary Boot Loader(or Partition Loader) instructions.
HOW TO SCAN MASTER BOOT RECORD FOR VIRUS WINDOWS
If it’s a hard disk boot case, like in any Microsoft Windows workstation, the BIOS will look for MBR.
Also during this boot sequence stage, user can get access to various BIOS settings or configurations by pressing the “Delete” button when the POST informations are displayed for 1-2 seconds. But if a DVD is inserted, the user is prompted with “Press any key to boot from CD/DVD” message. If, for example the first boot device is set to DVD-ROM but there is not any DVD inserted, the BIOS will check automatically the second boot device in the order list for a boot record. In these routines the video card is initialized, RAM memory chips, hard drives or other drives(CD-ROM, DVD-ROM, USB devices) are tested and their details displayed and the last step is to read the configuration stored in CMOS memory to see what is the order set for boot devices. BIOS performs basic tests on the present hardware, loads if necessary other BIOS routines(for example for video cards) and finally executes Power On Self Test(POST) routines.
HOW TO SCAN MASTER BOOT RECORD FOR VIRUS PC
For who does know what is a boot record Master Boot Record(MBR) or Volume Boot Record(VBR) the advantages of a such infection are obvious.įor who does not know about MBR or VBR and their role, here are the details of an Windows PC boot sequence in a simplified form. Like their predecessors, the Stoned computer virus(created 1987), Brain(created 1986 and the first PC virus !), Michelangel0(1991), Elk Cloner(1980), actual boot record viruses use the same method of infection: they replace boot record codes with infected code. Coming from the oldest computing times,the boot record viruses remain still one of the most preffered attack vectors.