In October 2005, Windows expert Mark Russinovich broke the news about a truly underhanded copy-protection technology that had gone horribly wrong. Certain Sony Music CDs came with a program that silently loaded itself onto your PC when you inserted the disc into a CD-ROM drive. Extended Copy Protection (or XCP, as it was called) stymied attempts to rip the disc by injecting a rootkit into Windows
The concept of the rootkit isn't a new one, and dates back to the days of Unix. An intruder could use a kit of common Unix tools, recompiled to allow an intruder to have administrative or root access without leaving traces behind. Rootkits, as we've come to know them today, are programs designed to conceal themselves from both the operating system and the user

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