Internet services slowed for Melita customers on Wednesday afternoon as the telecommunications provider faced a cyberattack.
Customers of the country's largest internet provider reported being intermittently unable to load websites or send messages using online services starting from just after 12.30pm.
In a statement, the company said that it was suffering a DDOS attack by "cybercriminals aiming to extort money".
The attack was still ongoing several hours later, though Melita said at 6pm that it had been "largely mitigated" and that services were returning to normal.
A DDOS attack, or distributed denial-of-service attack is a commonly-used method by which cybercriminals overwhelm a website or web service with too much traffic, forcing it to crash.
Melita said none of its systems had been breached as a result of the attack and that customer data was safe. The attack has been reported to the police.
"Internet services are being disrupted and Melita’s team is implementing mitigation measures to counter and resolve the threat as it evolves," the company said.
It said that DDOS attacks were a relatively frequent affair and often handled in the background, without any impact on users. Wednesday's attack, however, was "one of the most sophisticated yet," the company said.
A company spokesperson said calls, SMS and television services were not affected.
The company did not provide an indication of when it expected normal service to resume.
Melita is Malta's largest internet service provider with 49.31 per cent of all broadband subscriptions, according to a 2019 report published by the Malta Communications Authority.