Largest trial court in the US closes after ransomware attack, California officials say

LOS ANGELES (AP) — The largest trial court in the country was closed Monday after a ransomware attack shut down its computer system late last week, officials with the Superior Court of Los Angeles County said.

The court disabled its computer network upon discovery of the cybersecurity attack early Friday, and the system remained down through the weekend. Courts remained open for business Friday, but officials said all 36 courthouse locations in the county would be closed Monday.

“The Court experienced an unprecedented cyber-attack on Friday which has resulted in the need to shut down nearly all network systems in order to contain the damage, protect the integrity and confidentiality of information and ensure future network stability and security,″ Presiding Judge Samantha P. Jessner said in a statement.

Officials said Monday night that all 36 courthouses would reopen on Tuesday.

“As a result of the tireless work of court staff and security experts, the Court will reopen all 36 courthouses tomorrow, July 23,” according to a statement posted on the court website. “Court users should expect delays and potential impacts due to limits in functionality.”

The attack was not believed to be related to the faulty CrowdStrike software update that disrupted airlines, hospitals and governments around the world, officials said in a statement Friday.

A preliminary investigation shows no evidence that users’ data was compromised, according to Friday's statement.

The Superior Court of Los Angeles County is the largest unified superior court in the United States, serving the county’s 10 million residents over 36 courthouses. Nearly 1.2 million cases were filed and 2,200 jury trials were conducted in 2022.