The Malaysiakini website was once again attacked starting from 2.45pm yesterday. Although the cyberattack continued, the site was fully restored at 11.30pm.
It appeared that this was not an isolated attack against Malaysiakini - simultaneous attacks were launch against a number of other websites in the country.
At press time, most these websites, including those of opposition parties DAP, PAS and PKR remain unavailable.
In a Twitter message, DAP leader Lim Kit Siang said: "DDoS attacks on DAP, PAS, PKR websites since afternoon. Umno/BN cyber saboteurs rehearsing even more serious DDoS in 13GE."
The attack against Malaysiakini was the most sophisticated to date. "It used a complex attack pattern, and not easily detectable," said CEO Premesh Chandran.
The attack - commonly known as a Distributed Denial of Service (DDoS) - managed to overwhelm the Malaysiakini servers.
It involves using a large number of computers to flood Malaysiakini's servers with fake traffic, causing a traffic jam which denies access to legitimate users.
The attack is normally carried out by international syndicates paid to disrupt targeted websites.
However, Malaysiakini's technology team was able to bring the site back up after battling the debilitating attack for eight hours.
Over the past year, Malaysiakini has been hit with a number cyberattacks, most notably during the Bersih 2.0 and 3.0 rallies as well as the Sarawak state election.