Service NSW was the victim of a cyber attack last month after being targeted by a phishing campaign.
The government department confirmed the incident on Thursday following an investigation that began on 22 April when the breach was discovered.
Investigations determined that 47 staff accounts were accessed in the attack.
CEO of Service NSW, Damon Rees, was apologetic about the incident.
“Cyber security is incredibly important and we’re very sorry that we haven’t been able to successfully protect our customers against this complex attack,” Rees said in a statement.
“We are now working as quickly as possible to confirm the scope of this attack on the personal information of our customers.”
Reece offered reassurances that the bad actors only reached data contained in those 47 staff email accounts and would not have accessed MyServiceNSW account data.
“We are now confident the criminal access was limited to the content of those email accounts, which are related to transactions over the phone or over-the-counter at a Service NSW Centre,” Rees said.
“We are going to do everything we possibly can to help customers who have been affected by this. We’ve established a dedicated team to offer help to affected customers.
“Service NSW will contact customers who we determine have been affected by this criminal attack.
“This is a very complex issue and the analysis and investigation are both ongoing.”
Service NSW recommends people who have experienced suspicious online activity review their existing accounts, reset passwords and PINs, delete suspicious emails or texts, and be cautious about giving personal information over the internet.
Service NSW operates government services and transactions relating to public transport; births, deaths and marriages; housing; and the NSW Police.
Last year, Service NSW introduced a digital driver’s license which works through a ServiceNSW app tied to the user’s MyServiceNSW account.
The digital ID can be presented to police officers, licensed venues, and retailers as a form identification.