Adrian Croft and Peter Apps write the hacking incident affected the webpage of an affiliated cybersecurity hub in Estonia as well as the alliance’s unclassified email network.
The alliance did not disclose who was responsible for the attack but a group named Cyber Berkut declared in a website that it initiated the attack, according to the article.
Many cyber warfare experts believe the attacks are linked to NATO’s intervention in the ongoing tension in Crimea, Croft and Apps write.
The alliance opposes Crimea’s decision to hold a referendum with the intent to separate from Ukraine and join Russia, according to the report.