The Reserve Bank of Australia says it has been subject to a cyber attack and is in the midst of a security crackdown.
The attack occurred late in 2011, when a series of suspicious emails targeted six senior staff at the bank, the ABC reports.
According to an internal report titled "targeted email attack", six staff clicked on an embedded hyperlink to what is described as a "virus payload".
The Australian Reserve Bank is well known for its tight security and says its integrity was not compromised, but there are concerns that Chinese-developed spy software is posing a major threat to government institutions including central banks.