Russia appears to be carrying out one of its biggest VPN blocking campaigns in recent memory. Here’s what we know.

Amnezia, one of Russia’s most popular VPN services, reported on August 4 that Russian authorities had launched a new attack on tools used to bypass internet blocking. The attack had been underway for at least several days, according to the post. Amnezia representatives did not provide details about the new wave of blocking.

SecurityLab reported that several VPN services experienced outages and connection problems on August 4. According to the outlet’s journalists, the new restrictions hit IP addresses and entire subnets belonging to major hosting providers, though SecurityLab did not name the services affected.

Meduza reviewed the social media accounts of several VPN services popular among Russians and found a post from Paper VPN, published on the afternoon of August 4, acknowledging problems. That post also did not specify what might have caused the outages.

Commenters confirmed the service was experiencing disruptions, with some saying that switching connection locations helped. Others said they hadn’t noticed any problems, or that Paper VPN was working, just more slowly than usual.

The independent Russian investigative outlet Agentstvo stated that VPN Legend, GaMMa VPN, LTVPN, ABS, and FoxyBot have also reported restrictions, with posts from each saying the blocking affected only some of their servers.

Leonid Volkov, one of the leaders of the Anti-Corruption Foundation, called the current attack on independent VPN services “the biggest in history” on his Telegram channel, without specifying what led him to that conclusion.

Volkov suggested the new restrictions have proven effective because Russian apps — including banking and marketplace apps — track users, allowing the federal media regulator Roskomnadzor to compile a large database of IP addresses and carry out a large-scale attack.

Cyberlawyer Sarkis Darbinyan made the same argument in comments to Agentstvo.

The Telegram channel Eksploit (“Exploit”) calculated that the restrictions affected more than 20 popular VPNs, calling it one of the biggest attacks on blocking-circumvention services in recent memory. Though it’s not yet possible to assess the real scope.

A day earlier, sources who spoke to the Russian business news outlet RBC reported that the Digital Development Ministry wants tighter control over the IP addresses of corporate VPNs permitted for use in Russia. Those addresses currently sit on a special list exempt from blocking, according to the outlet’s sources.

“Disguised” VPN services designed to bypass Russian government restrictions regularly end up on that list, however. The ministry wants to work with hosting providers on a mechanism for continuous monitoring that would allow suspicious IP addresses to be quickly removed from the list.

It remains unclear whether the new wave of blocking is connected to those discussions, or whether Roskomnadzor is using any new methods to fight VPNs.

Amnezia suffered a large-scale attack earlier this summer that lasted a month and a half, affecting not only the service’s servers but the company’s broader infrastructure — including its payment system, which faced DDoS attacks. Amnezia representatives are confident Roskomnadzor is behind the campaign.