Slight correction, it is Remmina, not Remira.
Just to add I never sign up to internet banking following a Which? report years ago where they discovered that the most secure banking app was 85% secure. I stick with telephone banking, refuse voice recognition, and have statements delivered in snail mail.
Whilst GNU/Linux is not susceptible to viruses which need an .exe (which is why I don't use WINE/Windows App Support), there is always a chance email might be carrying a virus which you wouldn't want to forward to a friend or relative still using Windows so you could setup ClamTK Anti-Virus to scan your emails. Additionally, Evolution email can utilise Spam filters such as Bogofilter.
Something that all computers are vulnerable to are Rootkits. These nasties hide themselves in the system and take control of your machine without you knowing in order to launch attacks on other systems. For protection, install rkhunter and chkrootkit. These are comnand line tools that you run in the Terminal. They look at the system for rootkits and report back. You need to be aware though that these programs take a snapshot of your system at point of when they get installed, so if you were to install more applications after first run you will get some false positives because it has determined changes to what the base snapshot holds. However there is a new rootkit on the block that cannot be detected called 'curing'. Rootkits depend on system calls to work, but curing does not need to use system calls and so cannot be picked up by the usual rootkit hunters.
The biggest security flaw of any system is P.I.C.N.I.C. (Problem In Chair Not In Computer). Being careful on Browser use and checking site authenticity will prevent you from ransomware attacks.
Additionally some applications that are wrapped inside tarballs can contain malware so the method to check I reproduced Blackwolf's guide (a moderator for the defunct Ultimate Edition Oz forum) in the Unofficial Manual for Zorin 15 and 17 Core.