Delta Air Lines Inc. sued cybersecurity company CrowdStrike Titles Inc. faced with the chaos caused this summer by a “catastrophic” disaster software update which disabled millions of computers worldwide and grounded much of the airline’s passenger fleet.

The update paralyzed Delta operations for days, causing thousands of flight cancellations and delays that affected more than a million of its customers, the airline said in the complaint.

CrowdStrike publicly apologized after the July 19 issue shut down computers running the Microsoft Windows operating system. The disruption crippled airports, banks, stock exchanges and businesses around the world – and proved particularly difficult for Delta, which struggled for days to get its flight schedule back to normal. CrowdStrike has since announced significant changes to the way it tests and deploys content updates.

Delta claims the faulty update cost the airline at least $500 million in losses — in addition to “severe harm to its reputation and goodwill,” according to the complaint filed Friday in a court in Delta. State of Georgia.

CrowdStrike said in a statement that Delta’s claims are based on misinformation that “demonstrates a lack of understanding of how modern cybersecurity works and reflects a desperate attempt to blame its slow recovery on its failure to modernize its infrastructure.” outdated IT.

The cybersecurity company said it tried to reach an amicable resolution regarding the update, but “Delta chose a different path.”

Delta claims the software update was “forced” on the company – and was not installed by its IT staff.

“These updates were applied to customers and their systems even when customers did not enable automatic update settings,” according to the complaint.

Delta’s claims against CrowdStrike include fraud, breach of contract, deceptive trade practices and computer intrusion.

CrowdStrike also faces investor litigation following the outage.