The source is in the article, actually. This is the order from FSB that MTS operator received.
They translated this as: “the mass distribution of obviously false reports of a terrorist act” in January, resulting in “mass evacuations of schools, administrative buildings and shopping centers.”
Right before the IP addresses list, you can find terms "blackhole", "BGP".
The document has a signature of a head of the FSB center that handles this types of requests and orders. Also, you can see a stamp in the right bottom corner on the first page.
Full story, how a Russian internet company has actually found out about blackholing can be found here (in Russian): https://habr.com/ru/company/tm/blog/443222/
In the story, you can find that MTS confirmed that they are blocking traffic and referenced the order in the original article.
Right before the IP addresses list, you can find terms "blackhole", "BGP".
The document has a signature of a head of the FSB center that handles this types of requests and orders. Also, you can see a stamp in the right bottom corner on the first page.
Full story, how a Russian internet company has actually found out about blackholing can be found here (in Russian): https://habr.com/ru/company/tm/blog/443222/ In the story, you can find that MTS confirmed that they are blocking traffic and referenced the order in the original article.