Is remedial action needed if you click a link in an unsolicited 'scam-looking' email and the link went 404?

Question

Mac Mini 2.4GHz Core 2 Duo; 2GB memory; OS X 10.6.8. Incident occurred while using Firefox 35.0.
The latest/most current discussions I can find are from 2013 or older. Assuming more than a year is plenty of time for "new" malware or even "virus" that can affect Macs to be developed and distributed, I can either assume that "no news is good news"-- 'no new malware/virus possibilities' for Mac, or swallow my pride and ask the question: Is there any malware or other harmful/malicious computer code--read, something that could steal my identity if/when I do my taxes online this year--currently known to be a threat to home non-business Mac computers?
I ask because I committed the sin of all sins.....I got an unusual email from a vendor from whom I made one purchase (on ebay, a few months ago), asking me to loan "him" a sizable amount of money so he could "pay his hotel and retrieve his passport" while stranded in a foreign country. A very clear and not particularly uncommon scam method.....another flavor of the "grandma I'm in jail in Mexico" scam......and I'm one who constantly wonders how in the world people continue to allow themselves to get scammed (in my head when reading of other people doing it) by clicking on a link OR opening an 'attachment' in an unsolicited email. It wasn't tagged as "spam" by my ISP's very-good spam filters.....it was in my normal inbox; and, it was from a vendor I've done business with.
There was no attachment, but there was a link; I hovered the cursor over it; the lower left of my monitor showed the link exactly the same as it appeared on the page. I figured, well, it seems to be to the correct URL (knowing the seller's web address outside of ebay because I had visited it before finding he sold the same items on ebay). So, I clicked the link. Without a second thought. There was no other 'contact info' in the body of the email, so I thought the link looks authentic so I'll just go see if there's any information there about the owner being out of the country or ????.
The link took me to a Google "404" not found page. It was only there that I noticed the URL/link had an added letter; a stupid lack of attention on my part. The site could not be found because the URL was misspelled. I still was blissfully unaware that I violated my own rule (not to click links or attachments in unexpected email from entities I don't know or aren't currently transacting with). So I just closed the window and forgot about it.
It was only on waking this morning that I realized what I did.....and started worrying that I may have been directed to a phony "404" page that, without any further action on my part needed, might have contained something malicious that could be passed to anyone who connected to the page. I don't even know if that's possible, and I have so far not seen any unusual activity on the computer. But soon I will want to file my tax return....and I worry about the timing of this unusual-possible-scam email and the beginning of "tax time" here in the states?
So, in summary: Should I be worried that I fell for some new (since 2013) method of unknowingly downloading malicious software to my Mac? If so, what should I do now?

Answer 1

I don't even know if that's possible, and I have so far not seen any unusual activity on the computer.
No, it's not even remotely possible. What you encountered was an attempt to scam you, and a pathetic one at that.
Identity theft in general is a significant threat to any computer (a term encompassing Macs, PCs, iPads, iPhones...) user. However, that threat most commonly arises in the form of "phishing" and you didn't play along with it. The likely reason the email appeared to have come from one of your previous eBay vendors is that his email address was harvested using any number of methods. The email probably didn't even originate with him. eBay is a rich source for obtaining such information.
eBay has a fairly helpful guide on the subject: http://pages.ebay.com/help/account/recognizing-spoof.html
To answer your specific questions:
Is there any malware or other harmful/malicious computer code--read, something that could steal my identity if/when I do my taxes online this year--currently known to be a threat to home non-business Mac computers?
No.
So, in summary: Should I be worried that I fell for some new (since 2013) method of unknowingly downloading malicious software to my Mac?
No — although Mac-targeted adware has arisen since that time and is a rapidly growing annoyance that can make using your Mac practically impossible, it will not directly cause information theft as you have described it concerns you. Furthermore, it requires your participation to install it in the form of an Admin name and password — and it requires deception to convince you to supply those credentials. Learn more about how that happens here: How to install adware.