Considering that MacOS systems have relatively few exploits and are only very recently known to have trojan horse software, it is unlikely that someone made purchases from your computer leaving a trail back to you.
The timing of your question and this random web post from a couple days ago quoting the same e-mail address in a different site could mean you're the same affected fellow. The 1 single reply the person got is that there indeed is software on your computer that the new MacOS has found to "belong" to that particular ID.
From a screenshot in another website, your error message looks a little different for what other users see, because theirs aren't mentioning a specific e-mail address. Having unwanted things in one's computer is common these days of mega-downloading. I would search for both "Angry Birds" and "firstname.lastname@example.org" using your magnifying glass tool on the top right (Spotlight) and see if something does come up. You of course can't know the password to review past App store purchases for that other mail.ru (Russian) person, but it is likely that they somehow hacked it to avoid paying, and registered under this seemingly fake address, and somehow you got that one "altered" copy of the software. I'd just ignore it.