chkrootkit software package provides rootkit detector, you can install in your Ubuntu 12.04 LTS (Precise Pangolin) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install chkrootkit
chkrootkit is installed in your system.
Make ensure the chkrootkit package were installed using the commands given below,
$ sudo dpkg-query -l | grep chkrootkit *
You will get with chkrootkit package name, version, architecture and description in a table
| Distro | Ubuntu 12 04 lts precise pangolin |
| Section | Miscellaneous |
| Package | chkrootkit |
| Version | 0.49-4ubuntu1.1 [amd64, i386], |
| Description | rootkit detector |
| Sub Section | misc |