Image: ProtonMail

Belorussian authorities have blocked access to encrypted email provider ProtonMail on Friday last week, after receiving a wave of bomb threats from a mysterious attacker.

The threats, sent from a ProtonMail email address, warned private companies and government institutions of trinitrotoluene (TNT) bombs left and armed at various locations.

Targets included five Minsk hotels (known: Belarus, Garni, and Yubileynaya), three Minsk shopping malls (Capital, Dana Mall, and Galileo), the Minsk airport, several railway stations for multiple regional centers, the offices of tech news site Onliner, the Grodno office of chemical company Grodno-Nitrogen, and the the Novopolotsk offices of financial firm Naftan.

Local authorities reacted by ordering internet service providers (ISPs) to block access to ProtonMail IP addresses.

Ban is still in place

A ProtonMail spokesperson told ZDNet via email today that the ban is still in place. Local Belarussian users can't access the ProtonMail site, nor can they connect to the ProtonVPN service, the company told us.

ProtonMail said they've reached out to local authorities to request more information but have not received a response.

"As yet we have received no official communications from the Belarusian authorities or the Swiss authorities on the Belarusian's behalf," ProtonMail told ZDNet.

"ProtonMail abides by Swiss law and a request from Swiss authorities to block an account based on a court order would be honored. Sometimes, these requests are made by Swiss authorities on behalf of foreign authorities after judicial review and approval," the company said.

"We also have T&Cs [terms and conditions] for our users outlining what we consider to be inappropriate uses of our service. Where we have evidence that a user has broken these T&Cs we block their accounts," the spokesperson added. "Sending bomb threats would certainly be a violation of our T&Cs."

Ban won't stop future bomb threats

The Swiss email provider also disagrees with the Belarussian's state decision to block access to its service.

"The explanation for the block reported in local media does not, in our view, make sense," the ProtonMail spokesperson said.

"Blocking access to ProtonMail would not prevent cybercriminals from sending threatening emails by using another email service, and would not be effective if the perpetrators were located outside of Belarus.

"It is also likely that cybercriminals would be able to easily bypass the block. But it does deny regular citizens of Belarus access to our secure email services," ProtonMail added. "It goes without saying that we do not believe the wholesale blocking of ProtonMail is justified, and we condemn this form of Internet censorship."

But the company has gone through this carousel before. This is the second time this year ProtonMail has had its service blocked because of bomb threats sent via its platform. It was previously banned in Russia, in March.

However, the Russian block is different from the one in Belarus. Russians can access and send emails via ProtonMail; however, they can't send emails to Russian domains.

It is also the second time ProtonMail is blocked in Belarus. The site was also temporarily banned in June during a sporting event organized in Minsk, according to media reports at the time [1, 2]. Authorities never explained the July ban.

Updated on November 25 to add that ProtonMail is now again accessible in Belarus.