At least 19 organisations in Kenya have been affected by the ransomware virus in an ongoing global hacking attack.
Communication Authority of Kenya (CA) on Friday issued the update, noting the "WannaCryptor" virus has infected networks and computers the East African nation.
The number is an increase from the previous five reported on May 13 by the authority in an attack that has affected over half a million users globally as anxiety mounts amid today's deadline issued by the hackers, Xinhua reported.
"The authority will continue working with stakeholders to mitigate the effects of such instances while encouraging parties to put in place preventive mechanisms," said the authority's director-general Francis Wangusi.
Information and Communication Technology Cabinet Secretary Joe Mucheru had named Kenyan banks as among institutions targeted in the large-scale attack against computers worldwide that began last week.
He noted the software encrypts systems and denies the owner access to them, while the perpetrators demand payment using Bitcoin to allow access.
"Individuals and organisations are discouraged from paying the ransom, as this does not guarantee access will be restored," said Wangusi.
The authority formed the National Kenya Computer Incident Response Team (National KE-CIRT) to help in the coordination of fighting the virus.
CA said National KE-CIRT is working with other government agencies, banks, telecoms, academia and information technology experts to enhance security of Kenya's cyber infrastructure.
Almost 80 percent of Kenya's servers are based on Windows, another 16 percent on unix or the Linux variant, making the country vulnerable.
Industry experts noted that more companies are likely to be targeted before the end of the hacker's deadline, but added tracking the firms may present a challenge as many businesses are likely to shy away from publicising the attacks.
Tens of thousands of computer users around the world are anxious as the deadline to pay ransom issued by hackers is set to end today.
"WannaCry" has exposed the widespread susceptibility of computers across the globe, with Kenyan experts asking firms to backup data in flash drives and cloud.