Glossary
Macro virus
A macro virus is a virus written in the macro programming language of some office application - e.g., Microsoft Word, Microsoft Excel, Microsoft PowerPoint, Microsoft Access, Microsoft Visio and so on. Although most of the existing macro viruses (and other macro malware) are written for the Microsoft office applications, the reason for this is only the huge popularity of the latter. Macro viruses exist for practically every application that supports a macro programming language - e.g., OpenOffice, AutoCAD and so on.
Malware, Malicious Software
Malware is an abbreviation for "malicious software". It is the common term for all forms of software that are intentionally designed by their creator to inflict some form of damage to their user. The term "damage" is used in a very broad meaning; it can be anything the user does not approve of. It can range from simple replication (viruses), to collecting personal information (spyware), to stealing login credentials (password stealers), to displaying unwanted advertisements (adware), to simple destruction of the user's data (Trojan horses).
Mass-Mailer
A mass-mailer is a virus spreading by e-mail, usually as an attachment to an e-mail message. The attachment is executable in one form or another - e.g., either a directly executable file or a document containing macros, or a script. The e-mail message body and/or subject usually contains information designed to entice the user into opening/executing the malicious attachment. Upon execution, the virus examines the address book(s) of the computer it is running on and sends itself in e-mails to all the contacts listed there. In the past, such viruses used to be rather prevalent. However, contemporary versions of the popular e-mail clients (e.g., Microsoft Outlook) make it difficult for a program to automatically send e-mails via them (e.g., they display some kind of warning that requires manual user response) and the e-mail gateways routinely filter out e-mails with executable attachments.