SSH access issue - credentials not working


I am having a weird issue with SSH access to volumio:

I installed volumio and enabled SSH, and I was able to connect without problems. However, after few days turned on, the default login credentials are not working anymore. I get the SSH prompt and can enter the user and pw, but I get access denied… this is what I get using Putty:

login as: volumio
volumio@'s password:
Access denied
volumio@'s password:

I have not touched the volumio since last time connected, so for sure the password has not been changed. I had same problem some weeks ago and decided to reinstall, but it´s happening again… this is why I decided to ask over here. The GUI access is working normally, and the functions are also Ok.

Is there any way to restore the SSH credentials without reinstalling the machine? What could cause this access issue?

Thank you very much!

Volumio Information

Volumio Version: 2.799
Hardware: Raspberry PI 3
DAC: HiFiBerry DAC Plus

Try this:
Shut down Volumio, eject the microSD card, mount it in your OS of choice.
Go to the /etc/passwd file. I can’t remember which partition it is in, but it is in one of them.
Look for the line that reads:
Remove the x. Save the file.
The volumio user now has no password. Put the card back in your device.
SSH to your device, login as volumio.
At the prompt, enter:
passwd volumio
Change your password.

Hi @truckershitch, thanks for your answer.

I removed the microSD and mounted all 3 partitions in a Linux server but the passwd file is not located in any of these… it seems to be located in a squashfs (volumio_current.sqsh). In order to update the passwd file is required to expand the squash file, modify the passwd and compress the fs…

So I decided to restore it to factory default again. In any case, if the password was changed one of the options is the volumio was compromised, so it could have malicious files, etc.