A program designed to hide its presence while copying itself across systems is commonly referred to as what?

The term used to describe a program that hides its presence while replicating itself across systems is "worm." Worms are a type of malware that are capable of self-replication, allowing them to spread without the need for a host file or user intervention. They exploit vulnerabilities in operating systems or applications to propagate themselves from one machine to another, often leveraging network connections. Unlike viruses, which attach themselves to other executable files and require a host to execute, worms can operate independently and can typically spread more rapidly across networks.

Worms can also employ various techniques to mask their presence, making detection and remediation more challenging for security systems. This stealth mechanism enables them to infiltrate systems and networks without drawing attention, thereby increasing their potential to cause harm or gather sensitive information.

In contrast, adware primarily focuses on delivering advertisements and may not necessarily replicate itself, while rootkits are used to gain unauthorized access and control over a computer without detection but do not inherently spread across systems like worms. Viruses attach themselves to executable files and require user action to spread, making worms distinct in their autonomous behavior.