Malicious Macro

A macro is an automated input sequence that imitates keystrokes or mouse actions. A macro is typically used to replace a repetitive series of keyboard and mouse actions and are common in spreadsheet and word processing applications like MS Excel and MS Word.

A malicious macro, or macro virus is a computer virus that replaces a macro. When these actions and commands are replaced by a virus, this can cause significant harm to a computer.

Macro viruses can be built into sophisticated applications in order to run programs so that they can be launched automatically. Because macro viruses replace prompt commands, word processors are especially vulnerable to these types of viruses. The language is built into the macros in order to hijack the commands, including necessary actions like opening up a document. Thus, through the simple action of opening a document, a macro virus can be launched. Macro viruses may be spread through email attachments, modems and on the Internet, networks, and disks.

By and large, macro viruses are launched by simply opening a document. The macro virus is initially embedded in one document or a few documents, but it can spread to other documents within the same computer, as well reaching out to other computers through shared documents. Unfortunately, not all macro viruses can be detected by anti-virus software, although there are some good products available that can be used to detect them.