There has been a "lapse in the maintenance" of the People's Association websites, said Minister for Communications and Information Yaacob Ibrahim.
Dr Yaacob was responding to questions from Mr Baey Yam Keng (Tampines GRC) on the hacking of at least 17 websites linked to the People's Association in December.
He said that his ministry was aware of a vulnerability in the software tool and that agencies using the software were told to conduct maintenance ahead of time.
"There was a lapse in maintenance and the agency responsible has informed us that they will step up the maintenance regime to ensure that the checking and auditing is done more timely," he said.
He said in parliament that preliminary investigations have traced the hacking activities to foreign Internet Protocol addresses, and that he Police have requested assistance from their foreign counterparts.
He added that personal information of visitors to the website were not compromised as the websites provide general information about the People's Association activities.