Notes on Boot Sector Virus

Boot sector viruses infect the boot sector or the disk table partition of a disk. The infection prominently occurs in computers by these viruses when the infected floppy disk is inserted. The boot attempt does not bring any success in infecting the computer hard drive. Once a boot sector virus gets a hold of the computer, it leads to causing an infection on every disk that it gains access to and overwrites the existing program. But these viruses can be removed. There are programs currently known by the name ‘bootkits.’ The code is written to MBR to eagerly load in booting and then malware action concealing under the Windows operating system.  

Spreading of Boot Sector Viruses methods to get rid of them

Physical media is the primary factor in why Boot sector computer viruses are spread. USB Drive and floppy disk that is infected when connected to the computer when VBR of the drive is read will be ready to transfer and then further will replace the boot code that is already existing.   Viruses are locked and loaded and will run as the master boot record part when the user boots the desktop the next time. Email attachments are also prone to virus codes. If these emails are opened, they can infect the boot sector or harm the computer, and instructions may be set to send other emails to a further lot of computers via the contact list stored. BIOS architecture improvements have necessarily led to a reduction in boot viruses spreading and an option to minimise and prevent modification incurred in computer hard drive first sector.  

Removing the boot sector viruses is difficult because encryption of the boot sector may occur. In many instances, the users are unaware that the infection has been spread until an antivirus program has been installed or a scan is done on the computer. This results in users relying on protection programs with a huge registry of boot viruses and data for removal. If the viruses cannot be eradicated due to some damage or encryption, formatting can be a viable option for infection elimination.

Types of boot sector virus

Boot sector viruses are of two types: Older types run from storage media, the first sector is used for starting the computer. This type was evident when floppy disks were still in trend for DOS-based booting. 

The older type exists on media such as DVD ROM, CD, flash drives and other removable storage. Some recent and prominent viruses that infect the master boot record. Although they don’t target the actual boot sector precisely, they still indulge themselves in the boot process and certainly copy themselves to another part of the disk containing malicious actions.   

Precautions and damage control

Vigilance and avoiding contact with unknown disks are usually referred to as prevention. Some suggestions will certainly help maintain safe data:

• One of the best methods for protection against infection of boot sector viruses is using a good antivirus program that is well updated. The Antivirus has two functions in general:

• Scanning and removal of viruses on-disk files. 
• The operation of the computer for the activity that resembles virus activity and evaluation of actions known of specific viruses and has a generic suspicious activity. 

• Files should be backed up so that they can be restored if infected by a virus.

Note: If a file backup is already infected with a virus, re-infection can occur to the computer once it’s restored from backup. It’s important to check backup files before restoring them. 

• Keep the system disks, and original application writes protected. This will help prevent the virus from spreading to the original disks. 
• If one of the application floppy disks is inserted into an unknown computer, it should be locked first. Unlock the application disk only when verified that the device is virus-free. 
• Software about the public domain should be obtained from only reputed sources. Software should not be downloaded directly to a hard disk. It should be saved to a floppy disk and then locked and checked thoroughly by antivirus software. 
• The files should not be copied to the hard disk until safety is guaranteed. Help in protection from some Trojan horse programs.

Infected computers should be quarantined. If a computer is in the proximity of the virus program, it should be immediately isolated. If you say this, disconnect it from the network it is on. Copying and overwriting the existing program to other systems should not be allowed as it can cause infection to spread.

Conclusion

A boot sector refers to the reserved disk section consisting of the code and data needed to start the computer operating system. A boot sector virus is a malware type that infects the boot sector partition or the hard disk Master Boot Record (MBR). When starting and before the execution of the security software, the virus makes its presence known by executing malicious and dangerous code. Once the computer is infected, the virus will try to take over every disk accessed by the infected system.