Bung: The log in history is interesting. I have had no indication that anything was wrong, I've not had any odd email and so far none of my contact list have had anything supposedly from me but the history shows that the account was accessed from India on Sunday night.
The Indian login was flagged as suspicious but I wouldn't have known about it unless I'd been prompted to look by this thread. If it's flagged as unusual why can't Yahoo send an email to the account holder or give that as a choice?
Are you sure you haven't clicked on any suspicious links that were emailed to you? If you ever went to a "work at home for free" web site accidently then you may have been impacted.
Feel free to email me pl at telecom.co.nz and I can look further, however if I suggest you change your password as an extra precaution.