© Reuters. People look at the exchange rates that are displayed on the NZ Stock Exchange in Wellington
(Reuters) – The New Zealand Stock Exchange resumed trading Friday after experiencing disruption for four consecutive days this week following cyberattacks, while the government said national security systems had been activated to help the exchange.
There is no clarity as to who is behind these two "offshore" attacks, but failure to stop them has raised questions about New Zealand's security systems, experts said.
NZX Ltd had to cease trading by Friday afternoon after it crashed earlier due to network connectivity issues. This was the fourth day that trade was affected.
Treasury Secretary Grant Robertson said the Government Security Security Bureau and the national agency to combat cybercrime had been brought in to help the stock market.
"I can't go into much more detail than to say that we as a government take this very seriously," Robertson said at a press conference in Wellington.
NZX was hit by Distributed Denial of Service (DDoS) attacks on Tuesday and Wednesday. This is a common way of disrupting a server by becoming overwhelmed by a flood of Internet traffic.
The attacks forced the NZX to cease trading in its cash markets, disrupting business in its debt market, the Fonterra shareholder market and the derivatives market.
"Four days in a row are going to be frustrating and quite disruptive," said Jeremy Sullivan, investment advisor at brokerage Hamilton Hindin Greene in Christchurch.
Activity is very little, but institutional traders are still able to get "negotiated deals" through the market by speaking directly to one another, he added.
"The market is physically capable of running. They stalled it so people would not be penalized when the essential information website wasn't available."
NZX's Board of Directors, Debt Market and Fonterra Shareholder Market resumed trading at 1:00 p.m. (1:00 a.m. GMT).
Following the previous Friday crash, NZX had stated that it had "encountered connectivity issues similar to those caused by severe offshore DDoS attacks this week".
There were no details about the source or the impact of the attack.
"We can see that the Internet traffic came through the global gateway, so we know that it came from the coast, but it is nearly impossible to identify where it came from," network service provider Spark told Reuters.
New Zealand, a relatively small economy of five million people, is not often the target of such attacks, but neighboring Australia has increased its cybersecurity this year after a surge in similar incidents.
Australia said it would spend A $ 1.66 billion ($ 1.19 billion) over a 10-year period to bolster cyber defense.
The Central Bank of New Zealand said cyber attacks could wipe out around 2-3% of banking and insurance industry profits each year.
"The first attack can happen at any time. But being attacked for four days in a row raises some questions," said Rizwan Asghar, professor at the University of Auckland's School of Computer Science.
"The real question is what resources have been allocated and what thresholds have been set to protect against these attacks."