A major information system outage occurred worldwide on the morning of July 19, 2024. Cybersecurity Expert Dr. Ahmet Şenol noted that an update sent by Crowdstrike affected Windows-powered computers, bringing operations in many sectors to a standstill, stating, "As of July 19, it appears the root cause of the problem is Crowdstrike sending an update to computers without sufficient testing."
Dr. Ahmet Şenol: "Since the affected computer is currently inaccessible, each computer needs to be manually addressed to resolve the issue."
Dr. Ahmet Şenol, Head of the Cybersecurity Master's Program Department at Üsküdar Üniversitesi, evaluated the worldwide information system outage on July 19.
Not caused by cyberattack or malicious software
Dr. Ahmet Şenol reminded that as of the morning of July 19, 2024, Turkish time, a major information system outage occurred worldwide, rendering the systems of many giant companies and organizations, such as airlines, hospitals, and banks, inoperable. He stated, "First of all, this was not the result of a cyberattack or malicious software. It became clear that the problem was caused by a patch sent to systems by Crowdstrike, a company that provides security infrastructure to large companies and organizations."
'Blue screen' appeared on user computers
Dr. Ahmet Şenol, explaining that Crowdstrike develops software to actively protect systems, said, "Crowdstrike has monitoring software called Falkon sensor, which runs on all servers of protected companies. An update sent early on July 19, 2024, Turkish time, caused problems only on Windows-powered computers; it did not cause problems on MacOS and Linux-based systems. On Windows-powered servers or normal user computers, a 'blue screen' occurred, meaning the operating system was not providing service and the computers became unusable."
Started in Australia
Dr. Ahmet Şenol explained that this situation first occurred in Australia, rendering some banks and airports there inoperable. He continued, "It then affected Europe, the USA, and other regions. In the United Kingdom, the SkyNews channel became unable to broadcast. Delta, United, and American Airlines flights were halted. Turkish Airlines canceled 84 flights due to this issue. Information was also obtained that Denizbank's systems were affected."
Each computer needs to be manually addressed to resolve the issue
Stating, "As of July 19, it appears the root cause of the problem is Crowdstrike sending an update to computers without sufficient testing," Dr. Ahmet Şenol concluded his remarks as follows:
"Although Crowdstrike has explained on its website which update caused the problem and how the problem can be fixed on a specific device, since the affected computer is currently inaccessible, each computer needs to be manually addressed to resolve the issue. The Windows operating system needs to be opened in safe mode, a file deleted, and the system restarted, and this needs to be done separately for each device. It is estimated that it may take two days for the problem to be fully resolved."