Norwegian news agencies report that several top companies have been targeted in an ongoing phishing campaign and could be one of the largest cases of data theft in the country.

Few details have been released so far but online 'Views and News from Norway' reports that 'National security unit NSM (Nasjonal sikkerhetsmyndighet) and police intelligence unit PST (Politiets sikkerhetstjeneste) believe the goal of the computer spies is to gather information on secret contracts, industrial drawings, user names and passwords' according to their source the newspaper 'Aftenposten'.

Top executives in organizations at the heart of Norway's critical infrastructure are said to have been targeted in a long running phishing attack. Malicious programs that locate and extract senstive information are thought to have entered computer systems by tricking key employees into clicking on attachments to emails sent by the data spies in a sophisticated and ongoing campaign.

None of the companies in the attacks have been named and investigations are continuing into the latest attack that happened earlier this month.