Proton

As few weeks back, we sent a notice to the Proton community regarding the DDoS attacks that we have been facing. Today we would like to provide a brief update of the situation.

  • Starting on June 27th, Proton Mail started to be hit by sustained DDoS attacks.
  • The attack campaign continues to this day, but there has been little to no user impact.
  • Thus far the attacks have included:
    • Rapidly morphing DDoS attacks with the combination of SYN floods, TCP handshake violations (first packets are not SYNs), IPv4 TCP SYN floods, TCP Zero Sequence, ACK Floods, NTP nonstandard port floods, and reflection attacks on SSDP, NTP, Chargen, LDAP and Memcache protocols.
    • Pulsed/Burst DDoS attacks, with multiple attack vectors and rapid changes within minutes.
    • Attacks up to 25Gbs in volume. This attack was largely challenging to handle because of its complexity, not the size/volume. No unknown attack vectors were used, but they were rapidly changing, and hence the complexity.

Since November 2015, Proton Mail has been protected by Radware’s Cloud DDoS Protection Services, and in this instance, Radware was able to successfully mitigate nearly all of these attacks. However, due to the nature of the ferocity and attack ingenuity, some of the attacks were only partially mitigated and briefly resulted in some service outages at the outset of the campaign.

In order to improve mitigation performance, Radware immediately upgraded their scrubbing centers and processes to provide better protection against rapidly changing attacks. As a result, attack mitigation through the upgraded Radware scrubbing center has been successful in the past couple weeks.

After the upgrade, we have found that Radware’s technology actually works well against rapidly evolving attacks, and the automatic mitigation capabilities are essential for reducing the response times when coming under attack frequently. We also deeply appreciate the support that we have received from the team at Radware, and the fact that they made defending Proton Mail a priority. Going forward, we plan to utilize a multi-layered DDoS defense strategy and will continue to partner with Radware on the first line of defense.

We appreciate your patience through these attacks and look forward continuing to provide you with secure and private email services.

Related articles

file management for teams
Learn how to set up a secure, efficient file management system for your team and keep everything organized with Proton Drive.
'A very perilous moment': Journalists feel under assault
At Proton, we believe the best way to protect press freedom is to give journalists tools that make them harder to target — and easier to trust.
The cover image for a Proton Pass blog about World Password Day, showing a purple globe with three password fields on it
On World Password Day, Proton Pass asks the question: Do we need passwords anymore? Are there better alternatives? Find out in our blog.
Illustration of a QR code inside an envelope with an alert symbol suggesting the code is part of a scam
Quishing works by tricking people into scanning a scam QR code disguised to look legitimate. Here's how to protect yourself from quishing scams.
Can I change my Gmail address without creating a new account?
This article will guide you through several ways you can edit your Gmail address by adding a few small tweaks.
A stylized icon resembling the Google Photos logo with a dark triangular warning sign containing an exclamation mark, representing Google Photos safety issues
Is Google Photos secure to share private pictures? Here's how its protections can fall short — and other options for safer photo sharing.