Windows Blue Screen of Death could be a rootkit infection caused by the Tdss-rootkit which surfaced in the year 2008.
It appears that the affected machines had the rootkit infection by the deployment of Microsoft patches. Researchers isolated the atapi.sys file. They say that the atapi.sys is a good target for a rootkit attack because the atapi.sys loads early in the boot process. Once infected it is hard to replace the atapi.sys file. And the file is known to be able to "defend"itself.