Sicko cyber-crooks defaced the Mauthausen-Gusen concentration camp memorial website with images of child abuse late last week.
The attack on the site coincided with the run up to the 70th anniversary of the liberation of the Nazi death camp by US troops in May 1945 as well as wider VE-Day commemorations.
The site (en.mauthausen-memorial.at) was restored to normal by Monday lunchtime after initially being deactivated in the immediate aftermath of the attack.
Austrian police are investigating the assault. Interior Minister Johanna Mikl-Leitner called it a "criminal, sick attack and deeply abhorrent", the BBC reports.
The Nazis slaughtered more than 100,000 people at Mauthausen in the seven years between 1938 and 1945.
Far-right extremists are suspected of involvement in the assault, which was condemned by the head of Austria's Mauthausen Committee. ®