ALBANY — Albany Mayor Kathy Sheehan on Saturday said in a social media post that the city experienced a ransomware cyber attack.

"We are currently determining the extent of the compromise. We are committed to keeping you informed and will provide updates as they become available," she tweeted.

Further details on the attack weren't immediately available, including any specific areas the attack targeted, what it means for city residents and employees, who is being called in to help fight the problem and when it could be resolved.

City spokesman Brian Shea, reached Saturday afternoon, declined to comment.

A ransomware attack happens when a hacker denies an owner access to a system or personal files, and demands a ransom for the victim to regain access. Typically, ransomware hackers demand payment via cryptocurrency or credit card.

This story has been corrected to clarify that in a ransomware cyber attack, a hacker denies the owner access to system files.