Cyber-criminals targeted Nasdaq OMX Group’s community forum website and gained access to the email usernames and passwords of the members of the site, which took two days to come back online on Thursday evening.
The New York-based exchange operator said in an emailed letter to users of the forum that no e-commerce or transactions of any kind were taking place on the website. The forum was open to the general public to join.
Nasdaq spokesman Joseph Christinat could not say how many people’s information may have been compromised.
The cyber-attack happened on Tuesday, the same day a report was released saying that around half of the world’s securities exchanges had been targeted by cyber-attacks last year.
Cyber-crime appears to on the rise both in terms of sophistication and complexity, widening the potential for infiltration and large-scale damage, the report, by the International Organization of Securities Commissions’ research department and the World Federation of Exchanges Office, said.
A major attack could result in widespread public mistrust and a retreat from the markets, it added.