GitHub is under a Distributed Denial of Service (DDoS) attack. The site’s engineers are currently working on fighting back and the site is working sporadically as a result.

On Tuesday, GitHub experienced a partial service outage, and it took 26 minutes to resolve: from the company’s first confirmation to the final message. On Wednesday, the service was down for at least 24 minutes in another partial service outage.

On Thursday (today), the site has already been down for more than half an hour, at the time of writing, and GitHub is calling the issue a major service outage. A DDoS attack is to blame for today’s disruption, according to GitHub.

It’s not clear if the other two outages yesterday and the day before were caused by the same thing, but if they were, GitHub is not saying. On Tuesday, GitHub said there was “a network issue at one of [its] upstream providers” and on Wednesday the company said there were “errors with [its] search service.”

Visiting github.com earlier today resulted in a boilerplate maintenance message:

github maintenance 520x424 GitHub goes down on Tuesday and Wednesday, hit by major service outage due to DDoS on Thursday

Yet a visit to status.github.com quickly showed that this is far from a normal outage. Here’s the series of events so far today (we’ll add to the list as we learn more):

01:05 PM PST: We are investigating issues with GitHub.com
01:17 PM PST: We’re experiencing some connectivity issues at the moment. GitHub.com is currently unavailable while we resolve this.
01:33 PM PST: We are experiencing issues due to a DDOS attack, working hard to restore service
01:41 PM PST: Performance is still substantially sub par as we fend of the connection flood. We’re on it.
01:41 PM PST: We’ve temporarily disabled service on port 80 while we investigate the source of a connection flood. HTTPS, GIT, and SSH service are unaffected.
02:44 PM PST: Performance is stabilizing. We’re investigating additional mitigation strategies to harden ourselves against future attacks, similar or otherwise.

We have contacted GitHub for more information. We will update this article if and when we hear back.

Update at 4:35PM EST: GitHub has confirmed the issue on Twitter.

Update at 4:45PM EST: GitHub’s status page now says “Partial service outage.”

Update at 5:50PM EST: GitHub is starting to come back.

Update at 6:10PM EST: GitHub has nothing to add beyond what we already know. “The most up to date information about today’s service interruption is available, as always, at status.github.com – we’re working hard to restore service and will continue to update status.github.com with more information as it becomes available,” a GitHub spokesperson told The Next Web.

See also: GitHub goes down, second major service outage in two days

Image credit: Marco Soscia