The New Zealand stock exchange was knocked offline two days in a row due to a cyber-attack, on Tuesday.
New Zealand Exchange, NZX, said it had first been hit by a distributed denial of service (DDoS) attack from abroad “via its network service provider”.
A DDoS attack is a relatively simple type of cyber-attack, in which a large array of computers all try to connect to an online service at once, overwhelming its capacity.
They often use devices compromised by malware the owners do not know are part of the attack.
Due to this, genuine traders may have had problems carrying out their business. However, it does not mean any financial or personal information was accessed.
The exchange said the attack had “impacted NZX network connectivity” and it had decided to halt trading in cash markets.
New Zealand cyber-security organisation CertNZ issued an alert in November that emails were being sent to financial firms threatening DDoS attacks unless a ransom was paid.
The emails claimed to be from well known Russian hacking group Fancy Bear, but CertNZ said at the time the threat had never been carried out, beyond a 30-minute attack as a scare tactic.