Macro-virus
A macro virus is a type of computer virus often written in Visual Basic. Macro stands for macroinstruction, a group of programming commands that automatically executes whenever a file is opened or when you perform a specified action. A macro virus takes advantage of this automation by disguising itself as a normal macro. When you open a file infected with a macro virus, the software executes the malicious macro as though it were a normal one. Along with ransomware, spyware, and other types of malware, macro viruses can severely threaten you or your organization. In addition to wreaking havoc on a system, these macro viruses are also programmed to replicate and spread themselves in order to infect other systems. Macro viruses most often spread online via phony web links or as e-mail attachments.
Antivirus software is generally very well capable of removing macro-viruses.
Mail-command injection: IMAP/SMTP-attack
This is a type of attack, typically pointed at an e-mailserver using the SMTP-protocol in combination with none-at-all or poorly sanitised input.
An attacker could send commands to the mailserver to use the connection for bulk-sending of e-mailmessages and to manipulate the headers and body / actual content of the message.
Malware
Generally: malware is a catch-all concept of any type of program that you contract on your computer or mobile device which aims to do harm to your system and/or network. Typically: malware has the following intentions:
- Provide remote control for an attacker to use an infected machine.
- Send spam from the infected machine to unsuspecting targets.
- Investigate the infected user’s local network.
- Steal sensitive data.
For a list of malware programs see this page.
You can contract malware through downloading and installing programs and apps, browsing malicious websites or by using someone else's datacarriers like USB-sticks.
Mass-mailing worm
This type of worm is embedded in an e-mail attachment, and spreads using the infected computer's emailing networks. It distributes copies of itself in infectious executable files attached to fake e-mail messages. E-mail worms normally use social engineering tactics to trick the user into opening the email attachment. Mostly it spreads by sending itself to email addresses and instant message contacts. Users can avoid infection by simply refusing to open any e-mail file attachments without being 100% sure that it's safe.