Which statement best distinguishes a worm from a virus?

### Why this is right The course defines worms as self-replicating malware that spreads across networks without user intervention. A virus attaches to or infects files or programs and commonly spreads when the infected item is executed. ### The concept Malware is software designed to infiltrate, harm, exploit, disrupt, or gain unauthorized access to systems. Malware categories describe behavior, and real malicious programs can combine several behaviors. A Trojan horse is distinguished by disguising itself as legitimate software; ransomware is distinguished by locking or encrypting data and demanding payment. These labels are not interchangeable. ### The other options - **B. A worm is always disguised as legitimate software**: Disguise as legitimate software describes a Trojan horse, not the defining feature of a worm. - **C. A virus never infects files or programs**: File or program infection is a defining feature of a virus in the course material. - **D. A virus is defined by encrypting files for ransom**: That describes ransomware behavior, not a virus category. ### Terms - **Malware**: Malicious software designed to compromise, disrupt, exploit, or access systems. - **Worm**: Self-replicating malware that can spread across networks. - **Virus**: Malware that attaches to or infects files or programs. ### Remember Classify malware by its behavior: infection, autonomous spread, disguise, or ransom.