Which is not a malicious software?

The term 'Macro' refers to a legitimate automation feature in office applications (Excel, Word) that records sequences of commands. While macro viruses exist and are malicious, the macro feature itself is a neutral tool - not inherently malicious software. In contrast, Virus, Worm, and Rootkit are categories of malicious programs designed to cause harm or unauthorized access. This question tests understanding that 'macro' alone refers to the automation feature, not malware.