Contacted for comment, a party spokesperson told iTWire: "The matters raised are of serious concerns. We have referred the matter to police and we are conducting a full investigation."
This is the second attack by this gang on an Australian entity over the last few days, with the website of the Telstra dealer, Schepisi Communications, having been taken offline after it was hit.
On its site on the dark web, the group said NSW Labor had about 10 days left to make contact and "co-operate with us". Else, it said, data that had been stolen would be leaked.
The Avaddon gang also threatened to hit the party's website with a distributed denial-of-service attack and claimed that any data that had been encrypted would not be able to be decrypted using any external tool.
Photocopies of an Australian passport, a driver's licence and a number of other documents have been posted online.
Avaddon has not been used in many attacks as other strains of Windows ransomware. Prior to the attack on the Telstra dealer, only two other hits were reported by iTWire: one on an aircraft leasing asset manager and the other on a small businessman in Columbus, Ohio.
The security firm Emsisoft, which specialises in tackling ransomware, said in its latest report on the cost of ransomware in 2020 that there had been 2775 attacks on Australian organisations, based on submissions made to the ransomware identification service, ID Ransomware.
But this was believed to be only a quarter of the actual number, Emsisoft added.
