Ransom:Win32/Stopcrypt.Sab!Mtb is a type of ransomware that infects computers by encrypting the files on the system and demanding a ransom payment in exchange for the decryption key. This ransomware typically spreads through malicious email attachments, infected websites, or software downloads. Once a computer is infected, Ransom:Win32/Stopcrypt.Sab!Mtb will display a ransom note informing the user that their files have been encrypted and providing instructions on how to make the payment to receive the decryption key. It is important to regularly back up your files and avoid clicking on suspicious links or downloading unknown files to protect against ransomware threats like Ransom:Win32/Stopcrypt.Sab!Mtb.