The attack comes a week after Singapore announced a plan to spend 130 million Singapore dollars ($105 million) over the next five years to bolster research and human resources to make computer networks more secure against online attacks.
Baey Yam Keng, deputy chairman of Singapore's Parliamentary Committee for Communications and Information, said the attack illustrated how online security could be cracked.
"We do not know what the hacker's capabilities are, so it's important for us to take this very seriously," he said.
This week's threats are the latest attempt to pressure Singapore's government to reverse a policy introduced this year that requires some news websites to obtain licenses and possibly remove offensive content.
Activists accuse the government of extending censorship to the Internet in a country where the media have long been tightly supervised. Government officials maintain the website policy is not meant to muzzle freedom of expression but to ensure a minimum standard of reporting.
Bertha Henson, who runs a Singaporean news website called Breakfast Network, voiced concerns that Friday's hacking might hurt instead of help independent website operators.
"It makes the government seem right, that we are just troublemakers," she said.
