The company behind the Proton Mail email service, Proton, describes itself as a “neutral and safe haven for your personal data, committed to defending your freedom.”
But last month, Proton disabled email accounts belonging to journalists reporting on security breaches of various South Korean government computer systems following a complaint by an unspecified cybersecurity agency. After a public outcry, and multiple weeks, the journalists’ accounts were eventually reinstated — but the reporters and editors involved still want answers on how and why Proton decided to shut down the accounts in the first place.
Martin Shelton, deputy director of digital security at the Freedom of the Press Foundation, highlighted that numerous newsrooms use Proton’s services as alternatives to something like Gmail “specifically to avoid situations like this,” pointing out that “While it’s good to see that Proton is reconsidering account suspensions, journalists are among the users who need these and similar tools most.” Newsrooms like The Intercept, the Boston Globe, and the Tampa Bay Times all rely on Proton Mail for emailed tip submissions.
Shelton noted that perhaps Proton should “prioritize responding to journalists about account suspensions privately, rather than when they go viral.”
On Reddit, Proton’s official account stated that “Proton did not knowingly block journalists’ email accounts” and that the “situation has unfortunately been blown out of proportion.” Proton did not respond to The Intercept’s request for comment.
The two journalists whose accounts were disabled were working on an article published in the August issue of the long-running hacker zine Phrack. The story described how a sophisticated hacking operation — what’s known in cybersecurity parlance as an APT, or advanced persistent threat — had wormed its way into a number of South Korean computer networks, including those of the Ministry of Foreign Affairs and the military Defense Counterintelligence Command, or DCC.
The journalists, who published their story under the names Saber and cyb0rg, describe the hack as being consistent with the work of Kimsuky, a notorious North Korean state-backed APT sanctioned by the U.S. Treasury Department in 2023.
As they pieced the story together, emails viewed by The Intercept show that the authors followed cybersecurity best practices and conducted what’s known as responsible disclosure: notifying affected parties that a vulnerability has been discovered in their systems prior to publicizing the incident.
Saber and cyb0rg created a dedicated Proton Mail account to coordinate the responsible disclosures, then proceeded to notify the impacted parties, including the Ministry of Foreign Affairs and the DCC, and also notified South Korean cybersecurity organizations like the Korea Internet and Security Agency, and KrCERT/CC, the state-sponsored Computer Emergency Response Team. According to emails viewed by The Intercept, KrCERT wrote back to the authors, thanking them for their disclosure.
A note on cybersecurity jargon: CERTs are agencies consisting of cybersecurity experts specializing in dealing with and responding to security incidents. CERTs exist in over 70 countries — with some countries having multiple CERTs each specializing in a particular field such as the financial sector — and may be government-sponsored or private organizations. They adhere to a set of formal technical standards, such as being expected to react to reported cybersecurity threats and security incidents. A high-profile example of a CERT agency in the U.S. is the Cybersecurity and Infrastructure Agency, which has recently been gutted by the Trump administration.
... continue reading