Q: mac app store tells me to log into <edited by host> account to update apps(that I don't own) but that is not my account and I never heard of this email. Is there a fix for this?

Open App store and click on Account on the right, then click the account (it should be <edited by host>) then select sign out, then log back in using your account. 

I have the same problem. I have a Twitter client that needs updating and have received the same message as alejandro186. Has the Mac App store exploited? This thread is the only result in Google. It wouldn't surprise me if more start appearing over the next few days. So, who is this "tr33st"? Your fix, Eric, did not work, thanks anyway.

I have exactly the same problem and what Eric Ross said doesn't work for me too.

I had a similar problem when another person sign into the AppStore on my computer, but if both of you guys are getting the same login name I think that is a problem with the AppStore. 

Same here, what is going on!?!?

I would not trust anything or anyone using a @live.com address - I've been inundated with spam from people using that server; most of the names have been Eastern European.

So, I may be way off, but because of the currently circulating Trojan (search the forums for Mac Protector or Mac Defender) which presents itself as the "Apple Security Center", my first thought was that they might have infiltrated the App Store. I would be extremely careful - I would not click on anything, but would contact the store asap.

Same here. Weird. It's annoying as the App Store dock icon now always has a 1 badge on it. Anyway to fix this?

it's happening to me too!

come on apple fix this!

You are not contacting Apple here - these are user to user forums. Please contact the store asap (without clicking on anything you get in that window). Hopefully one of our volunteer experts in such things will chime in - until then, contact the store.

I'm getting the same issue and it's driving me insane. Surely there has to be a way of letting Apple know so they can provide a fix...

Delete any pirated applications from the mac app store especially facetime. Then the update should and email should go. Hope this helps.

EdStennett is correct. If you have a pirated app (in my case FaceTime) that is the cause. When I deleted Facetime (with Appzapper) the tr33st thing stopped.

good it worked! But why did it do that?

Everyone here - please take a look at this thread ( the last two posts by WZZZ and Thomas Reed):

https://discussions.apple.com/message/15205291#15205291

It appears that a) Hotmail has 19 domains functioning as distributors for malware and b) someone is distributing pirated software. Although it does not appear to be related to the recent trojan, my suggestion: stay away from both.

Edit: so why does everyone here appear to have pirated software (and doing it through it App Store)?????