[H] Linux Safe as I think?

[Winterlight]

I have been using Ubuntu  a lot this year in a virtual VM. My desktop 
is six core with 64GB of RAM so I can run lots of virtual desktops 
with full screen VMs. It has been quite a while since I ran anything 
Linux so I thought I would run it on a old Thinkpad X41 Tablet I have 
sitting around. So I installed Ubuntu and a number of different 
distros on my desktop to find the one I wanted to use on my X41.

 I decided on Elementary 0 and I like it a lot. In the discovery 
process I found myself using my desktop Ubuntu VM for lots of 
different online and off line expanding activities. Last night I was 
just about ready to log into my Ebay account and buy something from 
my Ubuntu Firefox browser when I paused because I really don't 
understand Linux down to the bone marrow like I do windows, and I am 
unsure if it is as safe as I think it is to use with sensitive 
information... something I have yet to do.

I am not running any Linux anti virus or malware program that I am 
aware of, I don't where the risks are, and goggling the issue brings 
up very few returns. So is Linux as safe, out of the box, as I think 
it is? And what is it about Linux and desktop security that I need to 
know that I am probably unaware of. Thanks!

w