The Alaska Department of Health and Social Services announced Thursday that a Division of Public Assistance computer storing sensitive information on more than 500 Alaskans had been compromised in an April cyber attack.

The Division of Public Assistance computer was reportedly infected by the Zeus trojan virus — malware that targets confidential information on computers running Microsoft Windows — on April 26.

DHSS Communications Director Katie Marquette says the infection was discovered on April 30, at which time the compromised computer was taken offline and a forensic investigation began. That investigation found that the virus bypassed multiple layers of security, and that the infected computer, which stored confidential documents on DPA clients, interacted with Russia-based IP addresses.

The documents accessed may have included names, health billing information, social security numbers, driver's license numbers, birthdates, phone numbers, and other confidential information.

Although the breach is still under investigation, Marquette says that so far, there are currently no indications that the stolen data has been exploited.

Marquette says the delay in disclosing the breach was necessary while investigators worked to learn the full scope of the breach.

Anyone who has had prior contact with the Division of Public Assistance Northern region (Fairbanks and Nome) is asked to call 888-484-9355 to find out if their personal information may have been compromised in the breach.