A penetration tester finds malware that spreads across a network without user interaction, replicating itself...

Comprehensive Explanation from CEH v13 Courseware:

CEH v13 describes worms as standalone malicious programs capable of self-replication without requiring user assistance. Unlike viruses, which need a host file and are triggered typically by user actions, worms propagate autonomously by scanning networks, exploiting vulnerabilities, or copying themselves to accessible machines. Worms are known for causing rapid, widespread damage by consuming bandwidth, degrading system performance, and creating backdoors for attackers. Classic examples such as Conficker, WannaCry, and SQL Slammer reinforce the destructive potential of automated propagation. CEH stresses that worms often use network shares, open ports, or unpatched vulnerabilities to move laterally. In contrast, keyloggers harvest keystrokes, ransomware encrypts data and demands payment, and viruses require user involvement to spread. The behavior in the scenario—automatic replication across the network—is the defining characteristic of worm activity according to CEH’s malware taxonomy.