yahoo mail compromised

A couple of weeks ago one of my yahoo mail accounts was used to send spam to everyone in the address book. I hadn't used that account in a while, but got one of the emails becuase my primary account was also in the other address book.

 

Is there any way to tell if my account is now actually secure? I did the usual about changing password, etc.  But my contact with Yahoo support was less than satisfactory. It took them 2 days to get back to me and basically, after I explained how I have NIS 2012 and it updates automatically, etc. they said it should keep me safe in the future from this type of problem. But since that was being done at the time of the problem, which Yahoo Support said was caused by a virus, I don't see why I should feel any safer in the future.  By the way, according to my Yahoo History sign-in log when the bogus emails were sent I was supposedly signed in from India on a Monday night and France the next morning even though I was in NY the whole time.