Stealth Syscall Redirection – This article describes a technique of redirecting system calls without modifying the sys call table (implemented in Linux). This can be used to evade intrusion detection systems that use the sys call table to register redirected or trojaned system calls. The basic premise behind this attack is to modify the old system call code to jump to the new system call, thus control is transferred to the replacement system call and the sys call table is left untouched.
You can download it from the following link: https://packetstormsecurity.com/files/download/24930/stealth-syscall.txt
Source: https://packetstormsecurity.com/files/24930/stealth-syscall.txt.html