Are there different classes of crimeware? What is considered crimeware?

Crimeware is not a single category within malware (malicious software), but is more a definition of all types of malware used for financial gain:

    Massive attacks: attacks aimed at a large number of potential victims.  No matter how small the percentage of people who are successfully tricked, as the number of recipients is so large, the attack can be highly profitable.
    Targeted attacks: these are silent, selective attacks. They can be more dangerous than massive attacks as they are more carefully prepared and more successful.
    Identity theft: the aim is to obtain confidential user information, in particular bank account numbers, credit card numbers, passwords, etc.
    Keyloggers: these are programs that capture keystrokes made by the user. All words entered through the keyboard will be visible to the attacker, from the text of email messages to information entered in forms, passwords, etc.
    Banker Trojans: these try to obtain information for accessing online banks used by the victim.
    Bots, botnets and zombies: these concepts are interrelated. A bot is a program that allows a system to be controlled remotely without either the knowledge or consent of the user. The compromised computer is known as a zombie. A network of zombies that receive and execute orders simultaneously, is called a botnet.
    Phishing: mass-mailing of messages which, using social engineering techniques, try to obtain user credentials for accessing online banking services.
    Spear phishing: this is a combination of phishing and targeted attacks: as it focuses on specific bank clients, it aims to be more credible and have a higher percentage of success.
    Dialer: program designed to switch the telephone connection being used to connect to the Internet to another, premium-rate, number. This activity results in an extremely expensive phone bill.
    Scam: A fraud designed to get a person or group of people to hand over money under false pretences, such as the promise of free holidays, lottery prizes, etc.
    Spam: junk email, normally mass-mailed advertising.  These types of messages can be highly annoying and consume both time and resources.
    Spyware: programs that gather data about users' Internet habits and preferences. This information is then sent to the creators of the spyware or to third parties.

Adware: programs that use various means for displaying advertising, such as: pop-ups, banners, changes to the browser home page or search page, etc. It is sometimes installed with the user's consent and knowledge, but on other occasions it is not. It operates in the same way regardless of whether the user has consented or not.