About 40 sites carried the messages "Hacked by EvLat" and "Freedom for all Muslims."
The Facebook page for Evlat shows websites in India and Malaysia were also hacked over the past few weeks, but its presence on the web is very limited.
Keven Ferland, CEO of Webshop, a web development company in Chicoutimi, said hackers often break into a shared internet server to spread their message.
In this case, most of the victims share the same web programmer, Perséides Technologies, which is based in Chicoutimi.
The company was in an emergency meeting this morning and was unavailable for comment.
Several of the websites had been restored by early afternoon.