The city of Baltimore has been hit by a ransomware attack, forcing officials to shut down a majority of its computer servers as a precaution. Ransomware works by encrypting files and locking them up so users can’t access them. The attackers then demand a ransom amount, typically in Bitcoin digital currency, in exchange for the decryption keys to unlock the files. A similar attack hit the Baltimore City’s phone system in March last year, shutting down dispatches for 911 and 311 calls for more than 15 hours.
Source: https://thehackernews.com/2019/05/baltimore-ransomware-cyberattack.html