Member Avatar for Dougie

I've recently installed AVG Anti-Virus free edition. I've done a couple of scans with no viruses found. Then today I did a scan, and right at the beginning of the scan this showed up under the "file" list ( Partition Table MBR) and under the result/infection list it said " Change ).

Does anyone know why this info showed up during the virus scan? I do know that MBR stands for master boot record ..... what does it all mean?

Thanks;

Dougie

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When AVG reported "Partition Table MBR — Change" immediately after a scan, that matched what suggested and what did earlier: the disk layout was altered. Below are concise, practical steps and cautions to confirm the finding is benign and to deal with it safely.

First, confirm the partition changes are exactly the ones intended. Verify sizes and drive letters in Windows Disk Management (or fdisk -l on Linux) and make sure the system boots normally. Make a raw backup of the first 512 bytes (MBR + partition table) before doing anything else so a known-good copy exists:

# On a Linux live USB, backing up the MBR of /dev/sda:
sudo dd if=/dev/sda of=~/mbr_backup.bin bs=512 count=1

If the change was intentional, AVG’s detection is usually harmless. As noted, the anti-virus often offers an action during the scan; if that prompt was missed, update AVG and run another full scan so the product reevaluates the current MBR. Check AVG’s scan reports or history for the exact timestamp and result.

If the change was unexpected, or if signs of infection appear (boot failures, new boot entries, unexplained disk activity), perform an offline scan with rescue media (bootable antivirus rescue disk) and compare the MBR backup against the current sector. If repair is necessary on Windows, the Recovery Environment commands below will overwrite the MBR (use only when certain):

bootrec /fixmbr
bootrec /fixboot

Cautions: overwriting the MBR can remove other bootloaders (GRUB) and break multi-boot setups. Keep backups, avoid blind fixes, and use rescue media or a second-opinion scanner if there is any doubt.

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Member Avatar for gerbil

Between scans did you make any alterations to the partitions on your HD? All primary partitions [and perhaps one extended partition] are recorded in the MBR; AVG will detect alterations....
If you did, tell it to accept the change.

Member Avatar for Dougie

Thanks gerbil. I suspected that, but wasn't sure. I did partition off the rest of my new 320 gb HDD using the disc management system. Never did that before LOL!!

Thanks for your help :)

Dougie

PS: Whre do you tell AVG to accept the changes. Looked everywhere and can't find it?

Member Avatar for gerbil

Just after you do a scan and it finds something... you only get the option then.

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