The article said that "purposing crafted emails, from attackers impersonating Singapore government officials of the APEC 2009 Organising Committee were sent to APEC officials and delegates of various APEC economies with the aim of infiltrating their computers and extracting privileged information."

"The attacks were highly targeted, focusing on members of the APEC Organising Committee and APEC delegates whose email addresses were published on various website or found within APEC mailing lists," the report said.

The article said that, in one of the first waves of Trojac attack, the perpetrators sent an email warning Singapore civil servants in the APEC meetings of impending terrorist attacks.

"The perpetrators further provided photos of supposed terrorists in a Microsoft PowerPoint document which was infected with malware. They played on the tightened security consciousness of the government officials to trigger and execute the malware, thus infecting the targeted computer systems."

The Home Team journal article said that "The malware used in these attacks were highly sophisticated and stealthy enough to evade the detection of most anti-virus programs."