The New Zealand Stock Exchange (NZX) said in a statement Thursday that it was working with cybersecurity experts and hoped to resume “normal trading” on Friday.
The exchange said it halted trading at around 4 p.m. local time (12:00 AM ET) Tuesday after experiencing a Distributed Denial of Service (DDoS) attack from outside the country. This was followed by further attacks on Wednesday and Thursday, which shut down trading in the debt and equity markets for most of the day. The derivatives market was also closed at 4 p.m. on Thursday.
DDoS attacks aim to disrupt service by flooding a network with large volumes of Internet traffic. A widespread DDoS attack in 2016 caused outages for some users on services such as Twitter ( and )Netflix (. )
The motive for the attack on the New Zealand stock market remains unclear, and NZX declined to say whether the attackers demand a ransom.
But this type of attack is becoming more common, as cybercriminals take advantage of the growth of public clouds and sell their services cheaply on the dark web. DDoS attacks jumped 542% in the first quarter of this year, compared to the last three months of 2019, according to cybersecurity firm Nexusguard.
“One of the reasons DDoS attacks are so inexpensive is that more and more people offering DDoS services for hire are leveraging the scale and bandwidth of public clouds,” said Juta Gurinaviciute, Director of technology at NordVPN Teams, the cloud network provider.