The four researchers into the rootkit protector created and implemented a special virtualized system that defends against persistent rootkits that tamper with kernel execution. The system assembles specific function calls and messages, mirrors them in a "shadow interrupt stack" in a central location and protects them from hardware write access. To test their product, called HookSafe, the team let loose a few real rootkits and also measured the system load on the host system. The result showed just a 6% system slowdown, but with a highly effective implementation of the protection.
The team found successful defense against, for example, the Adore-ng and Phalanx rootkits. Xuxian Jiang, one of the four team members, told Linux Pro Magazine that the HookSafe source code will probably be made public sometime in the future.
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