mdetect: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/mdetect - from package: mdetect

You may install the required package with command apt-get install {package}

Error in other languages:
mdetect: bevel nie gevind nie
mdetect: comandă negăsită
mdetect: comando não encontrado
mdetect: commande introuvable
mdetect: command not found
mdetect: käsku ei ole
mdetect: không tìm thấy lệnh
mdetect: komanda nerasta
mdetect: Kommando nicht gefunden.
mdetect: kommandot finns inte
mdetect: komut yok
mdetect: nie znaleziono polecenia
mdetect: níor aimsíodh an t-ordú
mdetect: no se encontró la orden
mdetect: no s'ha trobat l'ordre
mdetect: opdracht niet gevonden
mdetect: parancs nem található
mdetect: perintah tidak ditemukan
mdetect: príkaz nenájdený
mdetect: příkaz nenalezen
mdetect: команда не найдена
mdetect: командата не е открита
mdetect: 命令找不到
mdetect: コマンドが見つかりません