Comment 2 for bug 1792976

Thanks for filing this bug in Ubuntu.

It's unclear which steps you took led to this problem. You say you were removing clamav, but the logs show you were actually reinstalling it:
Start-Date: 2018-09-17 12:47:45
Commandline: /usr/sbin/synaptic
Requested-By: hector (1000)
Reinstall: clamav:amd64 (0.100.1+dfsg-1ubuntu0.18.04.2)
End-Date: 2018-09-17 12:47:48

Start-Date: 2018-09-17 12:48:16
Commandline: /usr/sbin/synaptic
Requested-By: hector (1000)
Reinstall: clamav-freshclam:amd64 (0.100.1+dfsg-1ubuntu0.18.04.2)

And over the same version, confirming it was a reinstallation:
Desempaquetando clamav-freshclam (0.100.1+dfsg-1ubuntu0.18.04.2) sobre (0.100.1+dfsg-1ubuntu0.18.04.2) ...

I tried that several times in a fresh bionic container (apt install --reinstall), but it always worked.

The /var/log/clamav directory is part of the clamav-base package, which is a dependency of clamav-freshclam. I wonder if perhaps you removed the /var/log/clamav directory manually? That would trigger the error you saw.

Since there are missing details, I'll have to mark this bug as "incomplete".