The following is a Google translation of a story that appears on securitylab.ru:
For hacking, it was enough for the victim to open a malicious email; no other action was required on her part.
Government-sponsored hackers exploited the zero-day vulnerability in the Estonian email service Mail.ee and hacked the accounts of a number of dignitaries.
According to a recent report by the Estonian Security Police (Kaitsepolitseiamet, KaPo), the incident took place last year, and the vulnerability has since been fixed.
Read more on securitylab.ru