iMAC virus protection

Do not worry about virus protection. No viruses for Mac. Only some troyans on hacked software

What plcn said.
As you are a newbie though, you might want to have a browse around to see what security you should have enabled. (In my experience at least), it's easy enough for switchers, even computer literate ones, to make mistakes as they are getting to learn a slightly new way of doing things.
For me, as a bare minimum - (referring to the Security pane of system preferences, I will have;
The firewall on, (and in its advanced tab: Enable stealth mode).
Checked the boxes for, Disable auto login, Require pswd for System prefs panes, Use secure virtual memory, require pswd after 15 mins.
- (referring to the Sharing pane of system preferences, I will have;
Nothing except essential services checked.

There are other things of course but it's up to you.

There is a - hopefully useful/informative - thread just below yours:

http://discussions.apple.com/thread.jspa?threadID=2365047&tstart=0

There's a little more to it than that. No viruses, true. There are a few trojans, and more specifically, they typically take the form of pirated software downloaded illegally (for example, one common trojan pretends to be an iWork installer) or "video plug-ins" that are "required" for watching skin flix on questionable web sites. In addition, as long as you aren't downloading through some torrent software or other such thing, those apps will be "quarantined." (If you've seen the "This app was downloaded, do you want to open it, blah, blah" warning, that's what quarantine does.) In Snow Leopard, there's an added benefit to this quarantine function... if you try to open a known trojan, it'll tell you.

So, you don't need virus protection now. But you should keep an eye on some Mac (or even general computer) news sites or RSS feeds... if a Mac virus pops up, it'll be big news.

Just by using a torrent to download something, might have been OpenOffice dev build, I noticed (or should say my router) a huge increase in DDoS. My IP was out there for harvesting. 😟

You don't need to download anything for that to happen. If I put a new computer on a public address it takes 5-20 minutes for attacks to start.

Maybe you should get an unpublished ip number 🙂

People round here seem to be complacent, or maybe that's just my take on things. Make sure you don't get like that.

None of those steps should. Which are you worried about?

frankie5 wrote:
Sorry, really another banal question for you I'm sure but you get to call your self a proper philanthropist!

Don't be silly. I learn just as much from these forums as you do.

Well had a few teething troubles getting my mail up and running so didn't want any of those settings to stop me being able to get my mail in.

Oh right, which I'm assuming are all sorted now.

When you said "nothing but essential services checked" I can see that window in the security settings menu, what would you class as things I should check in there?

I'm assuming you mean in the Sharing pane. What I mean is leave it all unchecked unless there is something specific you need. For example if you don't need +users of other computers to remotely view and control your computer+, then leave Screen Sharing unchecked.

frankie5 wrote:
Thanks for your comment that makes me feel a whole lot better.
The window I meant is in the advanced section of firewall settings, I dont have the "block all incoming connections" box ticked, and nothing below it in the white window- is this o'k?

That's fine. If you do have it checked and use things like MSN you'll have hassles. As for the white box below it, I believe it's where the exceptions go. Some apps that you might run on your Mac will require connections to the outside world through ports other than the default ones. When you run those apps you'll be presented with a window that goes along the lines of, +'do you want to accept incoming connections'+, when you allow those connections the rule will pop up here.

I have checked the other two boxes below as you suggested.
By the way the rather alarming flashing stuff I had up yesterday are .exe files and are still lurking in my downloads file thing on my dock. Shall I/can I delete them?

Anything .exe is for windoze and won't work. So unless you need it for something in particular, yes.