something 'arrived' midday as well as the earlier ft.exe
More than likely, the download was prompted by the same method the Flashback Java exploit used, which is why I had you turn off Java in the browser's preferences.
What such sites do is attack by using Java to initiate a Java applet on your computer. That in turn downloads the payload they really want to get on your system; which would probably be the cause of two separate downloads.
How secure are MACs these days -my Missing Manual book, which is a couple of years old say they are bullet proof and there is no need to run virus checkers etc.
noondaywitch pretty much already nailed it. I have never yet seen the need to install AV software on my Macs. All current Mac exploits are in one of three categories.
The older and more common type are Trojans (though there isn't even many of these). The perps try to get you to install malware on your system by making it sound like something you would want, or need. Until you initiate the installation, they can't do a thing.
The newer ones are jumping on the Flashback bandwagon and trying the Java end-around. Since Java is already running (if you have it on), they don't need to talk you into running an app, the browser will just do it.
The last and actually most prevalent is torrent downloads. That "free" copy of Photoshop you installed? There's no telling what else ended up on your system. The crooks pack these torrents with extra packages of stuff you definitely don't want on your system. Keyloggers, backdoors, etc. When you give any installer your admin password to install the software, it doesn't need to ask you again for the pieces you weren't expecting. The simple solution there of course is to never, ever download software from file sharing sites.