Sound the alarms: the internet was down ... well, some of it anyway.

Many of the biggest sites were down or screwed up Friday morning -- and an internet disruption could be the culprit.

New Hampshire-based Dyn, which provides internet traffic optimization for some of the biggest names on the web, said its servers were hit by a cyberattack early Friday morning. But the company says "services have been restored to normal."

Some users trying to access these sites still experience lingering issues, depending on their locations.

Here are some of the biggest sites reported to have been affected:

Twitter

SoundCloud

Spotify

Shopify

Esty

Grubhub

Yelp

Box

Boston Globe

New York Times

Github

Airbnb

Reddit

HBO Now

iHeartRadio

PayPal

Pinterest

The Associated Press contributed to this article.