sigfind: 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

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/sigfind - from package: sleuthkit

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