At the beginning of November 2013 attackers hiding behind the mask of Anonymous Ukraine arranged a campaign called #OpIndependence at the same time as a NATO exercise. The attacks included DDoS attacks, defacements and the sending of forged e-mail messages in several European countries.
The information systems of Estonian public institutions and businesses suffered no significant damage due to the attacks. The impact of the few hours of unavailability of the websites attacked was low. Recipients of the forged e-mail messages behaved responsively. The defacement case receiving wider attention once more stressed the importance of applying security patches to software.
The conclusion drawn from the incidents is that implementing additional technical and organisational means must be considered, and not only by the institutions attacked. The lessons learned due to the incidents prove the need to renew agreements and collaboration procedures between public institutions and between recipients and providers of hosting services.
