Computer networks of the smartwatch and electronics firm Garmin were coming back online Monday, the company said, after an outage widely believed to have been due to a ransomware attack.

The company acknowledged it was the victim of a "cyber attack that encrypted some of our systems," without offering details.

The comments suggest a ransomware attack which would have required a payment to hackers in order to get a decryption key.

"We are happy to report that many of the systems and services affected by the recent outage, including Garmin Connect, are returning to operation," Garmin said in an online post.

"Some features still have temporary limitations while all of the data is being processed."

The attack on July 23 disrupted Garmin's website; company communications, and customer-facing services, according to the Kansas-based company.

There was no indication customer data was stolen or functionality of Garmin products affected, the company said.

Garmin said its systems were  back online after an outage widely believed to have been cause dby a ransomware attack
Garmin said its systems were back online after an outage widely believed to have been cause dby a ransomware attack AFP / DAMIEN MEYER

"As our affected systems are restored, we expect some delays as the backlog of information is being processed," Garmin said.

Although Garmin Connect was not accessible during the outage, activity and health and wellness data collected from Garmin devices during the outage is stored on the device and will appear in Garmin Connect once the user syncs their device, according to the company.

Garmin Connect is a health and fitness tracker.

While Garmin has yet to explain the nature of the outage, analysts have speculated that the company fell victim to a so-called ransomware attack, in which hackers block a victim's access to its own data unless a ransom is paid.

The company's Garmin Pilot application, used by pilots to plan flights, was fully functional on Monday, as was the flyGarmin aviation database service, according to the company.

The outage affected Garmin's call centers, meaning the group was unable to respond to customers' phone calls, emails or online chats.

Some reports have linked the malware to a Russian cybercriminal group known as Evil Corp.