Unknown attackers attacked the Yandex search engine and the resources of some other Internet holdings, taking advantage of a flaw in the Roskomnadzor blocking register. This was reported by RBC with reference to sources in the industry.
The essence of the attack was to bind IP addresses to victim sites, access to which had previously been restricted by Roskomnadzor. As a result of such actions, some Russian providers began to block the attacked resources, and large operators redirected all their traffic through DPI systems, which reduced the access speed. The attack continued for several days.
The vulnerability used by hackers was discovered in the Roskomnadzor registry back in 2017, but the agency has not completely eliminated it.