What is a Boot Sector Virus and how to prevent or remove them?

Boot Sector Viruses are malicious programs that reside in your hard drive. They infect your car by replacing your Main Boot Tape (MBR) or DOS Boot Sector with their code. In some cases, kick sector viruses will encrypt the MBR. This mode of operation is what makes kick sector viruses are potent.

Boot Sector Virus

What is a Boot Sector Virus?

The Primary Boot Record is on the offset sector of your hard drive and executes whenever you power on your PC. This means that even if you endeavor to remove boot sector viruses using an antivirus, they go loaded back into your computer'southward retentivity on your next kicking.

Originating from your boot sector, these viruses volition then spread to all the disks on your estimator. This makes boot sector viruses tough to remove.

Also, if Windows is running, regular antivirus programs will not have access to the MBR. Yous tin, however, use bootable antivirus disks to remove kick sector viruses. This guide shows y'all how to practise this and other solutions for ridding your reckoner of boot sector viruses for good.

How to prevent Boot Sector Virus

While removing boot sector viruses is quite challenging, information technology'southward like shooting fish in a barrel to avert getting them in the first identify. The most mutual manner that these malicious programs spread is through shared removable media.

Earlier inserting any removable storage bulldoze into your calculator, you lot must be sure that it isn't infected with a kick sector virus. The virus may not get on your machine when you connect the media, just if you leave it connected while you boot upwardly your arrangement, then your hard drive will be infected.

Protecting your motorcar from boot sector viruses is similar to doing it for viruses in general – you must have reliable antivirus software and defenses and always continue their virus definitions updated. I can't overemphasize the roles of antivirus software. In this case, yous demand them for these two functions, primarily:

To monitor your computer organisation for malicious activity.
Detect known malicious actions and patterns in your reckoner system.
Browse for viruses and go rid of them from your system's disks.

In the section that follows, we'll get more in-depth on how these viruses infect your computer system.

TIP: Yous can protect your computer's Master Boot Record with MBR Filter.

How does a Boot Sector Virus get in?

As we've emphasized, kick sector viruses enter your PC mainly via physical storage media. However, they may likewise come up arranged in downloads, especially from untrusted sites and email attachments.

When you connect an infected USB pen drive or insert a floppy disk into your computer, the virus gets transferred to your system and infects the MBR. It modifies or completely replaces the existing MBR lawmaking, and on your next kicking, the virus is loaded into your organisation and runs with the MBR.

Regarding the download of infected files and email attachments, boot sector viruses remain more often than not harmless when you download them. Notwithstanding, when you lot open the malicious file, information technology then begins to infect the host machine. In many cases, the proprietor might've encoded instructions for the program to multiply and create batches to e-mail your contacts.

Thankfully, the computer BIOS architecture has improved, and this has curbed (to a large extent) the spread of boot sector viruses. This development is due to the inclusion of the pick to let users to block codes from modifying the start sector of PC's hard drives.

If you've never updated your BIOS, now'south a proficient time to do information technology.

Read: How to backup & restore Main Kicking Record with MBR Backup or MDHacker.

How to remove a Kick Sector Virus

Most boot sector viruses tin encrypt the MBR; your drive tin get severely damaged if yous don't remove the virus properly.

On the other hand, if the virus doesn't encrypt the MBR and merely infects the boot sector, you lot tin can utilize the DOS SYS command the restore the bad sector.

Further, you can also use the DOS LABEL command to restore affected volume labels. If the infection is astringent and across repair, you can supervene upon the MBR with the use of the FDISK/MBR command.

While all of these methods may piece of work for some cases, using a free bootable antivirus rescue software is the safest way to remove boot sector viruses. Most importantly, with antivirus software, you are unlikely to lose files and data saved on your difficult bulldoze.

Read: How to repair the Master Boot Tape.

TRIVIA: The first MS-DOS PC virus was created in 1986 and it was the Brain virus. Brain was a boot sector virus and but infected 360k floppy disks. Interestingly, even though it was the first virus, it had the full-stealth capability. V-Sign was the commencement polymorphic boot sector virus.

Boot Sector Virus