crowdstrike-microsoft-outage-BSOD

  • CrowdStrike revealed that the global IT outage that impacted transport, finance, and medical industries around the world was caused by a sensor configuration update for Windows gone wrong.
  • Crowdstrike Falcon Sensor for windows was updated for microsoft windows version 7.11 or above

when was the update?

  • july 19 windows update over the air
  • update time from 4:09 UTC to 5:27 UTC

what was the update for?

  • Falcon sensor update
  • update was designed to target newly observed, malicious named pipes being used by common C2 frameworks in cyberattacks
  • the configuration update triggered a logic error that resulted in an OS crash

what was the impact?

  • 8.5 million windows devices
  • US and Europe mostly
  • some corporates in india also faced the issue
  • what about china? -> well china hardly uses apps from american companies for their system
  • hospitals, airlines, shopping malls could not function properly
  • some reports of telephone and internet outages(not so clear about this info yet)
  • some reports of 911 emergency call outage in some US states

how did it happen?

  • some updates in the configuration files caused the issue
  • configuration files are called channel files in here: -> C:\Windows\System32\drivers\CrowdStrike\
  • “these are not kernel drivers but extensions”
  • microsoft kernel during boot loads the sys files
  • boot time issue with the sys files, BSOD while loading that file because it had issues

solution?

  • remove the files from the recovery process?
  • if you have bitlocker enabled, first allow bitlocker to decrypt the harddrive using your password
    • then remove the sys files

sources

  • referenced from various pages in the internet