More than 40 Indonesian agencies, including the ministry overseeing immigration, were impacted by a cyberattack on the country's data centres, an official said on Wednesday.
The latest cyberattack, the worst that the country has experienced in recent years, disrupted immigration services and affected operations at Indonesia's major airports for days.
Forty-four government agencies, including key ministries, were targets of the ransomware attack, said Usman Kansong, an official from the communications ministry.
Data at five agencies, including immigration services and the coordinating ministry of investment, have been restored, and the government is working to restore data at 39 other agencies, he said.
"We expect the data at 18 government agencies to be restored by the end of this month," Usman said.
In a joint press conference with the ministry, Telkom Group director Harlan Wijanarko tried to assure Indonesians by saying that their data was secure.
"We have isolated the system in the national data centre so no one can enter it. We cut the access from the outside," he said, adding that they were still investigating the cause of the attack.
The Telkom group operates two major data centres in Indonesia, one in the capital city of Jakarta and the other in Surabaya.
All government agencies in Indonesia rely on these centres to store data. The Surabaya data centre was the target of the attack.
Indonesia's communications ministry announced earlier this week that the attacker had used malicious software called Lockbit 3.0 and demanded an $8 million ransom, which the government refused.
The Lockbit cybercrime group is notorious for using ransomware to digitally extort its victims.
Ransom software works by encrypting victims' data. Hackers can offer a key in return for payments in millions of dollars, typically through cryptocurrency.

Qatar is not directly mediating between US and Iran, ministry spokesperson says
Germany, France in rare rebuke of Trump over Iran war
Philippine president declares energy emergency over Middle East conflict risks
New York's LaGuardia airport faces second day of delays, cancellations after collision
Iran sends missiles into Israel, dismisses Trump's talk of negotiations as 'fake news'
Lebanon declares Iranian envoy persona non grata, asks him to leave by Sunday
Iran denies talks with US after Trump postpones strikes on power grid
Israeli minister calls for annexation of southern Lebanon
