WordPress.com currently serves 30 million publishers, including VIPs and is responsible for 10% of all websites in the world, and WordPress.com itself sees about 300 million unique visits monthly -- is currently being targeted by a "extremely large Distributed Denial of Service attack which's affecting connectivity in some cases. The size of the attack is multiple Gigabits per second and tens of millions of packets per second."
"We're working to mitigate the attack, but because of the extreme size, it's proving rather difficult. At this time, everything should be back to normal as the attack has subsided, but we're actively working with our upstream providers on measures to prevent such attacks from affecting connectivity going forward.
We'll be making our VIP sites a priority in this endeavor, and as always, you can contact us via firstname.lastname@example.org for the latest update. We'll also update this post with more information as it becomes available," read the official blog post.
Automattic and WordPress founder Matt Mullenweg said,
"There's an ongoing DDoS attack that was large enough to impact all three of our datacenters in Chicago, San Antonio, and Dallas -- it's currently been neutralized but it's possible it could flare up again later, which we're taking proactive steps to implement.
This's the largest and most sustained attack we've seen in our 6 year history. We suspect it may have been politically motivated against one of our non-English blogs but we're still investigating and have no definitive evidence yet."
You can check here for the latest status updates.