“Hello. We are Vikingdom2015, the hacking crew, and we uploaded this track so we can warn American citizens. We will knock all American governments’ websites offline. We do not care if we get caught. We all like doing this. So you better be prepared for the battle.”

The same group responsible for posting this digitized-voice clip on SoundCloud.com has taken credit for temporarily disabling the Maine.gov website two mornings in a row, and state officials say there isn’t much they can do to prevent future attacks.

The central Internet portal for Maine state government offices was disabled for about three hours Monday and 2½ hours Tuesday, the target of seemingly random attacks on state government and other websites by a group claiming to be in Russia.

As a result, residents and businesses were temporarily unable to access online services to, for example, apply for a state license, register a vehicle or search incorporation papers and other public documents.

Vikingdom2015 boasted about the attacks both days via its Twitter feed with tweets such as “Maine cannot stop us” and “Other hackers helped us knock Maine.gov offline.”

In response to a tweet asking why a Russian hacker would target Maine, Vikingdom2015 replied, “cause they are dumb.”

The Twitter user also claimed to have temporarily disabled New Hampshire’s VisitNH.gov website on Monday and tweeted a link to a hit list of other state government sites it is threatening to attack.

The hackers used a method of attack on the Maine.gov website known as distributed denial of service, or DDoS, according to a LePage administration spokesman, Alexander Willette.

A DDoS attack involves flooding a website with thousands of simultaneous requests for data, causing it to become overwhelmed and lock up. The attack is “distributed” because the data requests are coming from many different computers working in tandem as part of a robot network, or “botnet.”

Botnets generally are made up of personal or business computers that have been infected with malicious software, allowing the botnet’s administrator to instruct them remotely to flood a particular website with data requests or perform other tasks. In most cases, owners of the infected “zombie” computers are unaware that their machines are part of a botnet.

Hackers don’t have to create their own botnets to conduct DDoS attacks, because there are botnet administrators on the black market who will take on jobs for hire. Once an attack is detected by a website’s security personnel, they often can isolate the geographic areas from which the disruptive data requests are being sent and block them, which makes the site functional again. However, Willette said it is virtually impossible to ward off DDoS attacks.

“To a certain extent, there is no way to inoculate the website against these attacks,” he said.

Subscribers to Maine.gov rich site summary – or RSS – feeds may have received a barrage of old messages Tuesday morning, the release of which was triggered by the site being switched over to a backup, Willette said.

The Department of Administrative and Financial Services is investigating the hacking incidents, and Willette said technicians from Information Resource of Maine – or InforME – are working to fix the problem.

The attackers’ motivation is unclear, Willette said, adding that state officials have not received any demands or other communications from the hacker group.

The Vikingdom15 Twitter account became active on March 16. Since then, its owner has taken credit for dozens of successful DDoS attacks on websites belonging to businesses, schools and state and local governments in the U.S. and other countries. U.S. state government websites it claims to have taken offline temporarily include Colorado, Georgia, Virginia, Alabama, Nebraska, Oregon, New Jersey, New Hampshire and Maine.

DDoS attacks do not give the perpetrators any access to private data, Willette said. Their sole purpose is to disrupt the normal functioning of a website.

But if there is no direct material gain, then why conduct such attacks?

“The motivation here is just plain old bragging rights,” said Glenn Wilson, director of the Maine Cyber Security Cluster and an associate research professor at the University of Southern Maine.

The hacker community is extremely hierarchical, Wilson said, and it’s common for less-sophisticated hackers to perpetrate attacks using tools developed by other, more advanced, hackers.

Vikingdom15 is likely trying to impress members of the hacker community and gain their respect by pulling high-profile stunts such as shutting down government websites, Wilson said.

“They’re just flexing their technological muscles,” he said.

Staff Writer Gillian Graham contributed to this report.