The Department of Information and Communications Technology (DICT) said no sensitive government information appeared to have been stolen in the hacking of the House of Representatives website.
The DICT said its initial check showed that the defaced pages mostly contained information already open to the public.
The agency, however, said the assessment was still preliminary and could change as investigators dig deeper into the breach.
The House website was defaced on Saturday, June 13, just two days after the Senate website suffered a similar attack.
The DICT said it quickly coordinated with the House after learning of the incident and activated its cyber incident response protocols.
The agency is now working with House officials and law enforcement units to trace the source, method, and extent of the unauthorized access.
For now, the DICT said its priority was to contain the breach, restore affected services, and tighten security across the compromised systems.
The agency warned that website defacement is a cybercrime under Republic Act No. 10175, or the Cybercrime Prevention Act of 2012, and those behind the attack could face charges.