Thousands of Australians may have had their personal data compromised, with a human resources company used by organisations including Coles and Medibank revealing a data breach.
PageUp, which claims to have more than two million active users, on Wednesday released a statement saying it had detected "unauthorised activity" on their system on May 23.
The ABC reports Telstra, the Reserve Bank of Australia, Officeworks, Kmart, NAB, Australia Post, the Australian Red Cross, Aldi and the ABC are also among PageUp's clients.
PageUp, which supplies job application software, says an investigation is ongoing.
The extent of any data breach is not yet known.
"We ... have been working together with international law enforcement, government authorities and independent security experts to fully investigate the matter," PageUp CEO Karen Cariss said in a statement.
"There is no evidence that there is still an active threat."
Coles has closed down its career website and has suspended all connections between its systems and PageUp's.
Coles put up a statement urging any person who has applied online with the company in the past year and a half to check if there had been any "recent unusual activity concerning their personal information".
Medibank has also suspended its careers page and is investigating whether the data of applicants has been compromised.
The Tasmanian government and the University of Tasmania (UTAS) have also been affected.
The state government's jobs website has been taken offline.
"As a precautionary measure, the government has suspended all connections between our systems and PageUp's systems," a spokeswoman said.
"This suspension will be in place until we are satisfied that PageUp is secure and there are no further risks."
UTAS says breached data may include the bank details, tax file numbers, mobile phone numbers and addresses of successful job applicants.
