disulfinder: command not found

Have You tried accessing the binary with the full path?

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/disulfinder - from package: disulfinder

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