At a press conference today, health director-general Dr Noor Hisham Abdullah said the 865 new cases bring the total number of infections in the country to 21,363.
The death toll meanwhile has climbed to 190.
Noor Hisham said there were 455 recoveries, bringing the total number of those discharged to 13,717.
The three deaths today were all from Sabah, comprising two Malaysians and a foreigner.
They were aged between 52 and 85, with one of them having a history of chronic illness. The others did not have any existing medical conditions.
Noor Hisham said there are now 7,456 active cases in the country, with 99 receiving intensive care and 32 of them requiring respiratory assistance.
Out of the 865 cases, only seven were imported cases, while the 858 local transmissions comprised 767 Malaysians and 91 foreigners.
Five cases today came from people who returned home from Sabah, pushing the total number of cases with travel history to Sabah since Sept 20 to 448.
Sabah recorded the highest increase in cases today with 643 infections, which is 74.3% of total cases.
Noor Hisham said the massive increase came about after more test samples were done in Sabah and sent to the peninsula to be processed.
Meanwhile, he said 13.5% of the total cases were from states in the Klang Valley.
Noor Hisham also said 154 of the cases were from clusters in prisons, such as Kepayan, Tembok and Seberang Perai.
Selangor recorded the second highest number of cases again today with 101, followed by Labuan with 34.
The bulk of these cases came from existing clusters, while positive cases were also detected in other Covid-19 screenings.
Penang reported 26 cases, Perak 18, Melaka 16 and Kuala Lumpur six.
There were also cases in Negeri Sembilan (4), Kedah (3), Putrajaya (3), Johor (2), Pahang (1) and Terengganu (1), all of which came from close-contact screenings, screening of returnees from high-risk areas or existing clusters.
The seven imported cases involved three Malaysians and four foreigners who arrived in Malaysia from China, Australia, the US and Qatar.
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