unhide-posix command not found

In this troubleshooting guide we learn how to fix unhide-posix command not found error message

Introduction

When you run more command in linux terminal / console, you get the following error message

unhide-posix: command not found

or when using sudo you get the following error message

sudo: unhide-posix: command not found

Solutions to unhide-posix: command not found

How To Fix unhide-posix: command not found in Ubuntu / Debian / Kali Linux / Raspbian

In Ubuntu unhide-posix is provided by unhide package.

unhide is:

Unhide is a forensic tool to find processes and TCP/UDP ports hidden by rootkits, Linux kernel modules or by other techniques. It includes two utilities: unhide and unhide-tcp.

unhide detects hidden processes using the following six techniques:

  • Compare /proc vs /bin/ps output
  • Compare info gathered from /bin/ps with info gathered by walking thru the procfs.
  • Compare info gathered from /bin/ps with info gathered from syscalls (syscall scanning).
  • Full PIDs space occupation (PIDs bruteforcing)
  • Reverse search, verify that all thread seen by ps are also seen by the kernel (/bin/ps output vs /proc, procfs walking and syscall)
  • Quick compare /proc, procfs walking and syscall vs /bin/ps output

unhide-tcp identifies TCP/UDP ports that are listening but are not listed in /bin/netstat through brute forcing of all TCP/UDP ports available.

This package can be used by rkhunter in its daily scans.

This package is useful for network security checks, in addition to forensics investigations.

To fix this problem, we can install more using the command below.

sudo apt-get -y install unhide

This command might take some time to finish depending on your machine internet connection.

You can also use apt command to install unhide.

sudo apt -y install unhide

Or if you have aptitude installed you can use the following command.

sudo aptitude install unhide

Summary

In this tutorial we learn how to fix unhide-posix command not found error in Ubuntu / Debian / Kali Linux or Raspbian distribution.