It just seems to me like a coincidence that the upgrade was followed by your G-Mail account being hijacked.
It could be that you have been firesheeped - even though G-Mail uses ssl by default, if you use the same password for something else, trying the same password with your email would the first test any spammer would do.
It could also be a simple phishing scam.
As a matter of fact, there are so many ways for an attacker to steal your password so If i where you i would:
1.Boot my computer from a live CD
2.Change all my passwords
3.Do a clean install of all my computers
If you have a lot of free time, before reinstalling everything you can try and find out which one of your machines is actually infected with malware. Try antiviruses, or maybe sniffing the network for random traffic thats not supposed to be there.
That is probably not enough,
you should also change your habits :
Don't login to your account from public machines/networks.And if you have to - use a live CD/USB to boot it.
Don't install just any software on your computer/iphone etc.. make sure it's from a reputable source
Don't use the same password for everything.
There is a lot more you can do but i think you get the hang of it - just be sensible on when and where you use your account.
It could be that you have been firesheeped - even though G-Mail uses ssl by default, if you use the same password for something else, trying the same password with your email would the first test any spammer would do. It could also be a simple phishing scam.
As a matter of fact, there are so many ways for an attacker to steal your password so If i where you i would: 1.Boot my computer from a live CD 2.Change all my passwords 3.Do a clean install of all my computers
If you have a lot of free time, before reinstalling everything you can try and find out which one of your machines is actually infected with malware. Try antiviruses, or maybe sniffing the network for random traffic thats not supposed to be there.
That is probably not enough, you should also change your habits : Don't login to your account from public machines/networks.And if you have to - use a live CD/USB to boot it. Don't install just any software on your computer/iphone etc.. make sure it's from a reputable source Don't use the same password for everything.
There is a lot more you can do but i think you get the hang of it - just be sensible on when and where you use your account.