awesome-linux-rootkits/details/reptile.md
Ilya V. Matveychikov 30806e974b
Update reptile.md
2018-07-02 20:14:03 +04:00

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# Reptile kernel rootkit details
https://github.com/f0rb1dd3n/Reptile
## Environment
- Linux kernel 2.6.x/3.x/4.x
- x86 (`sys_call_table` search method is x86-only)
## Persistency
Boot-time module loading using OS-specific startup files:
- /etc/modules
- /etc/rc.modules
## Detection evasion
Rootkit is trying to evade from detection by:
- hiding of own files
- hiding of kernel module by unlinking from `module_list`
- tampering contents of startup files while reading
## Management interface
Implemented via `kill(2)` by hooking `sys_call_table[__NR_kill]` entry. Supported commands are:
- hiding/unhiding processes
- hiding/unhiding rootkit's module
- enabling/disabling of tampering file content function
- gaining root priveleges to calling process
## Altering system (library) behaviour
Hooking of system calls by patching syscall-handlers in `sys_call_table[]`.
To write to read-only page `CR0/WP` technique used (x86-only).
## Hiding (tampering) of file contents
Filtering of file content while reading by hooking:
- `sys_call_table[__NR_read]`.
## Hiding of files and directories
Filtering of directory entries by hoocking:
- `sys_call_table[__NR_getdents]`, `sys_call_table[__NR_getdents64]`
## Hiding of processes and process trees
Filtering PID-like numeric entries while listing `/proc`.
Hidden tasks are marked using `task->flags \| 0x10000000`.
Not able to hide all threads and children of hidden (parent) process.