Voter registration data for over 19.2 million California residents that was residing on an unsecured MongoDB database has been deleted and held for ransom by attackers, according to researchers at Kromtech, who discovered the incident.

This continues a series of cyber-extortion attacks that exploit the MongoDB database management system. Similar to others, in this instance, the attacker scanned the internet for unsecured MongoDB databases, found the one containing the voter data, wiped the data and left a ransom request for 0.2 Bitcoin (around $3,500 US today), Bleeping Computer reports. 

The Kromtech researchers state they have not been able to identify the owner of the database. They "believe that this could have been a political action committee or a specific campaign based on the unofficial title of the repository ('cool_db'), but this is only a suspicion."

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