$CrowdStrike Holdings, Inc.(CRWD)$
CrowdStrike Microsoft Remediation
Symptoms of the Windows crash include hosts experiencing a bugcheck message or the Blue Screen of Death error, both of which are related to CrowdStrike Falcon Sensor update. CrowdStrike has indicated that channel file C-00000291*.sys with timestamp of 0409 UTC is the problematic version, and that channel file C-00000291*.sys with timestamp of 0527 UTC (July 19) or later is the reverted (good) version.
CrowdStrike has also indicated that Windows hosts that are brought online after 0527 UTC, Hosts running Windows 7/2008 R2, and Mac- or Linux-based hosts will not be impacted.
Current Actions for Remediation
Workaround Steps for individual hosts:
Reboot the host to give it an opportunity to download the reverted channel file. If the host crashes again, then:
Boot Windows into Safe Mode or the Windows Recovery Environment
NOTE: Putting the host on a wired network (as opposed to WiFi) and using Safe Mode with Networking can help remediation.
Navigate to the %WINDIR%\System32\drivers\CrowdStrike directory
Locate the file matching C-00000291*.sys and delete it.
Boot the host normally.
Note: Bitlocker-encrypted hosts may require a recovery key.
Workaround Steps for public cloud or similar environment including virtual:
Option 1:
βββββββDetach the operating system disk volume from the impacted virtual server
Create a snapshot or backup of the disk volume before proceeding further as a precaution against unintended changes
Attach/mount the volume to to a new virtual server
Navigate to the %WINDIR%\System32\drivers\CrowdStrike directory
Locate the file matching C-00000291*.sys and delete it.
Detach the volume from the new virtual server
Reattach the fixed volume to the impacted virtual server
Option 2:
βββββββRoll back to a snapshot before 0409 UTC.
Get Assistance If Still Affected
As many are affected worldwide, we understand that you might be impacted by the recent CrowdStrike agent issue and are working to fix it. I have posted the remediation here to help you.
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