Following the collapse of the family business, while salvaging the hard drives from the company PC's, we have retrieved a key drive with the most important company files. The majority of the files on the key drive were apparently encrypted by ransomware more than 10 years ago, but some later files have not been encrypted. I'm not sure what if anything the former user did when the ransomware appeared.
When I connected the infected drive to my laptop via USB and ran MB Premium, I got 20 infected files with general malware and PUP's, of course I quarantined those. The encrypted files are still visible in Explorer, however they each have a new file extension.
Is there a procedure using MB and other software to decrypt these files ?
Also I have MB scanned my laptop and no malware is detected. I have also ESET-scanned the laptop, no problems detected. Do I need to do anything else ?