An eye-watering 98.1 million accounts, and their cleartext passwords, have been stolen from Russia's biggest web portals Rambler.ru.

The breach occurred way back on 17 February 2012 according to breach repository site LeakedSource and appears to have gone unreported in intervening years.

It represents a significant win for hackers wanting to compromise Russian accounts.

The breach was reported by the same user who handed LeakedSource some 43.6 million cleartext breached Last.fm accounts also dating back to 2012.

"Nearly 100 million records have been leaked online in yet another mega breach," admins wrote on the site.

"Rambler.ru … are the Russian version of Yahoo."

The site competes with Russian social media giant VK.com a site that saw 171 accounts leaked in June.

Rambler did not respond to requests for comment by the time of publication. ®