Computer malware, or malicious software, can often masquerade as what is known as Scareware and Ransomware. Scareware is a type of scam software that leads a user to believe their system is infected with malware in an attempt to sell the user an app to rid their system of the "infection." Scareware plays on the user’s fear to sell the user the app.
Of the two, Ransomware is the more difficult to address. It is computer malware which holds all or part of a computer hostage against its user and demands payment or the purchase of products or services for restoration.