Criminals attacked the Basecamp network with a distributed denial-of-service attack (DDoS) this morning. The attackers tried to extort us for money to make it stop. We refused to give in and worked with our network providers to mitigate the attack the best we could. Then, about two hours after the attack started, it suddenly stopped.

We’ve been in contact with multiple other victims of the same group, and unfortunately the pattern in those cases were one of on/off attacks. So while things are currently back to normal for almost everyone (a few lingering network quarantine issues remain, but should be cleared up shortly), there’s no guarantee that the attack will not resume.

So for the time being we remain on high alert. We’re collaborating with the other victims of the same group and with law enforcement. These criminals are sophisticated and well-armed.

Still, we want to apologize for such mayhem on a Monday morning. Basecamp, and our other services, are an integral part of how most of our customers get work done. While no data was compromised in this attack, not being able to get to your data when you need it is unacceptable.

During the attack we were able to keep everyone up to date using a combination of status.basecamp.com, Twitter, and an off-site Gist (thank you GitHub!). We’ll use the same channels in case we’re attacked again. If the attack does not resume, we will post a complete technical postmortem within 48 hours.

We want to thank all our customers who were affected by this outage for their patience and support. It means the world to us. Thank you.