China and Russia lead list of Yahoo hack suspects – but some doubt theory

'It doesn't fit the normal intent' of state-sponsored attacks, some experts say, pointing to the lack of detailed information from Yahoo about the hack

If Yahoo is to be believed in its assertion that a nation-state hacked into its network and made off with user data from 500m accounts, then there are a few obvious suspects, including China and Russia.

However, Yahoo has not provided any detailed information about the attack, leading some security experts to raise questions over its origin. Why would nation-states be interested in or motivated to hack Yahoo?