secutil: 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 CentOS possible default full paths are:

/usr/bin/secutil - from package: mono-devel

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/secutil - from package: mono-devel

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

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