Which description best distinguishes a worm from a typical virus?

### Why this is right The material distinguishes a worm by its ability to spread without human interaction. A typical virus is attached to an executable or other host and depends on a person running or spreading it. ### The concept Both worms and viruses can copy themselves and infect other systems. Their key difference here is the means of propagation: worms exploit transport or file-sharing features to spread automatically, while typical viruses rely on a human action involving an infected host file. ### The other options - **B. A worm is always harmless, while a virus is always destructive.**: Both categories describe propagation, not whether the malware is harmful. - **C. A worm only conceals other software, while a virus only steals passwords.**: Concealment and information theft are functions that can occur in different malware types. - **D. A worm must be attached to a legitimate executable, while a virus never is.**: This reverses the material's typical distinction; viruses are commonly attached to files, while worms can spread independently. ### Terms - **Worm**: Malware that can spread to other systems without requiring a person to run an infected file. - **Virus**: Malware typically attached to a host file that relies on human action to execute or spread. - **Executable**: A file that can be run as a program. ### Remember For this distinction, ask whether spread requires a human to run or pass along an infected file.