In most cases, recent attacks come in the form of phishing schemes and internet-related hacks rather than viruses. These would be cases where someone gets your information through something like somethingThatLooksLegit.somethingfake.com somethingfake.com would be the actual website that you are accessing, and since you can download webpages and re-host them, fake webpages can be used for stealing web logins. These tend to be the simplest to execute, and phishing scams tend to be unfortunately extremely successful and more lucrative than anything else in the online scamming world.
Most infections that get reported in cases like
@PavelGubarev are Windows viruses that you could possibly transfer through your email. Windows tends to be extremely different from Macs in terms of back-wards compatibility due to their Enterprise status. A Windows XP program has no problems running on a Windows 10 computer. That means that every bug that needs to exist because some backwards compatibility requires it to persist will still be there. Macs tend to stay more secure by breaking backwards-compatability all the time. So while Windows has all that backwards-compatibility, there are some Apps that worked on Yosemite that I can't use on El Capitan unless the developer updates their app.
Macs do have a bit of a built-in system with Protect (File Quarantine). Those Gatekeeper notifications that pop up before opening an app get a lot more to-the-point when you try to open up an app that matches a pre-defined set of apps in Apple's database.
It's also somewhat helpful that El-Capitan uses rootless or System Integrity Protection as well. While it's profoundly frustrating for those of us who like to tinker with the lower-level parts of OS X, it's a very good thing to protect the lower levels of the system. Where before every time you entered your password into those install packages, the program could access everything down to your OS files, System Integrity Protection prevents even the administrator from changing those files without disabling SIP.
That said, we do still live in a world where a large majority of people use Windows computers. It's a bit harder to spread those viruses on a Mac computer as many batch scripts an .exe files won't run. In most cases, you would need to forward those messages before they could do anything malicious.
There is plenty out there in terms of antivirus software that works and that aren't scams, but in most cases they are eliminating viruses for the sake of herd-immunity rather than for the sake of keeping your computer safe.
I personally don't bother with antivirus except to do a random scan every once in a while with Bitdefender's app in the App Store (it's a small free app), but if you don't feel comfortable without it (you really should feel comfortable - you'll be fine) Sophos, ClamXav, Bitdefender and some others make decent (but really unnecessary) pieces of software.
IF YOU DECIDE TO TRY OUT BITDEFENDER'S APP STORE APP:
Make sure that you set the infected items action to Take no action in the preferences before scanning for the first time to check if it has any false positives. I had a false positive that it just deleted off the cuff without doing a quarantine or asking me about it first. This is one case where I would say Anti-Virus can actually be more detrimental on a mac than useful.
If you're more curious about this (I'm weird like that, so maybe you haven't even read this far), you can check out the pages on places like av-test
https://www.av-test.org/en/news/new...osshairs-18-malware-scanners-put-to-the-test/ for an independent security firm's take on OS X antivirus.
