"We have received a report confirming that 12 institutions were affected, but the figure could be higher," Rudiantara stated during a graduation ceremony held at the Malang Muhammadiyah University on Saturday.
The affected institutions include those in the plantation and manufacturing sectors, universities, and vehicle registration center located in Jakarta and other regions.
"However, in general, the attack was not significant as compared to that reported in other countries, thanks to the media that helped us to warn the public," he added.
Rudiantara admitted that Indonesia had yet to be free from the malware attack, with six to eight of the viruses still being active.
"Such viruses are less malicious than Wannacry, but they were here and attacked hundreds of computers in Indonesia," the minister cautioned.
Hence, Rudiantara has called on the public to regularly change the passwords of their accounts, emails, and ATM personal identification number to avoid virus attacks.
"Regularly back up data, update software, or download the newest version of anti-virus software," he remarked.
Earlier, on Wednesday, the minister had stated that Indonesia was already free from the WannaCry ransomware attack.
Ransomware is a malicious application designed to block access to computer systems and data by encrypting the files and demanding ransom to decrypt them.
The malware to have attacked thousands of computers across the world was the WannaCrypt0r 2.0 ransomware that breached the security gaps in the Windows operating system, patched by Microsoft in March through the Security Update Patch.
However, the malware could spread rapidly across the world, as several computers had not been updated.(*)