Russia has blocked a second encrypted email provider, Swiss-based ProtonMail, in efforts to halt a prolonged series of anonymous bomb threats, the security service said Wednesday.
The FSB security service said Russia acted against Geneva-based ProtonMail after blocking another social network, Netherlands-based Smartmail, for the same reason last week.
ProtonMail, a free encrypted email service, was used to send messages falsely claiming bombs had been planted in more than 800 public places in four regions, the FSB said.
“We have received reports that ProtonMail and ProtonVPN are currently partially blocked in Russia,” a spokesperson for the Geneva-based provider said.
“We are reaching out to the appropriate authorities to get the block lifted as soon as possible.”
Russia’s communications watchdog, Roskomnadzor, confirmed that access to ProtonMail was blocked Wednesday.
It accused the Swiss provider of failing to hand over information on email users who sent threats.
ProtonMail’s spokesperson denied this, saying “no communications have yet been received from the Russian authorities.”
The block will be ineffective against cybercriminals but deny access to “regular law-abiding citizens,” the spokesperson said.
The blocking of a second foreign email provider came as Russia scrambles to stop a wave of threats that have led to more than a million people being temporarily evacuated from thousands of buildings.
Both email providers were used to send messages to courts warning of bombs in numerous public buildings including shopping centres and hospitals, the security service said.
It did not give any motive for the attacks.
Some of the messages referred to controversial businessman Konstantin Malofeyev, and demanded he pay back cryptocurrency, according to media and the Saint Petersburg courts’ press service.
Malofeyev, a businessman and founder of an investment fund, is on US and EU sanctions lists for allegedly funding pro-Russian separatist fighters in eastern Ukraine.
Some threats mentioned 120 bitcoins worth almost $900,000 (800,000 euros), allegedly stolen from a crashed cryptocurrency exchange.
They refer to WEX, a now-defunct spinoff of BTC-e, once one of the world’s largest and most widely used digital currency exchanges, where national currencies can be exchanged for bitcoins.
Malofeyev has denied any involvement in WEX or stealing bitcoins.
The suspected head of BTC-e, Russian Alexander Vinnik, was arrested in Greece in 2017 and faces money laundering charges in several countries. He was extradited to France last week.
After the latest threats, courts in Russia’s second-largest city of Saint Petersburg were evacuated Wednesday morning, the city courts’ press service said.
In July, ProtonMail said that journalists from Bellingcat website investigating Russian military intelligence had suffered cyberattacks on their encrypted email accounts and suggested the attack was “of Russian origin”.