barracuda vpn in linux and /etc/resolv.conf
When connecting to the company network it is actually a wanted functionality that the vpn client modifies /etc/resolv.conf to allow using the cpmpany internal name server to resolve the internal host names to ip adresses that can be reached inside the tunnel and this only happens if it is configured on the vpn server side.
In my experience the client does undo those changes as soon as the vpn connection is closed down - however it doesn't work properly if the connection is not closed gracefully.
Typical issues are that you use a WLAN and start the vpn client and then loose contact to your wireless access point before closing down the VPN. You end up with improper entries in /etc/resolv.conf but network manager is as much to blame as the barracuda client - those two don't work nicely with each other as they are unaware anyone else might modify the file.
It is an annoying issue but netiher nefarious nor really security relevant so i would not label it "harmful".