DNS provider sitelutions was floored by a particularly severe denial of service on Tuesday.
The Virginia-based internet services firm confirmed its site was offline as the result of a "multi-gigabit" denial of service attack via an update to its Twitter feed.
"Websites and data still safe, though there are still occasional DNS lookup issues that we are working on due to the massive attack," it said.
sitelutions was able to restore its website by Tuesday afternoon following an outage of around six hours earlier in the day.
The motives for the attack, much less its perpetrators, remain unclear.
Typically such attacks are launched from botnets of compromised machines that are normally rented for the purpose by someone with a grudge against a targeted organisation, or just as often, a beef with one of their clients.
Attacks tend to subside after a short period unless the hacker is in the grip of rage, or is using the attack to extort money from a targeted site; this being a tactic that was fairly common a few years ago but has died off more recently in favour of more subtle scams.
Various DDoS mitigation tools can be applied to filter off and discard junk traffic, but these tend to take some time to properly install and configure. ®