Which scenario BEST illustrates horizontal movement within a compromised network?

• A. The pentester accesses shared folders on other systems using the same user account privileges and searches for sensitive documents.
• B. The pentester moves through the network at the same privilege level without attempting to escalate privileges, focusing on accessing data available at that level.
• C. The tester escalates privileges on the initial host to obtain administrative access on the next system.
• D. The tester targets external services without touching internal hosts.

Answer: (A)

Horizontal movement means moving from one machine to another within a compromised network while keeping the same level of access, using existing credentials to access data across multiple hosts rather than raising privileges. The scenario where the tester uses the same user account privileges to access shared folders on other systems and searches for sensitive documents is a clear example: it shows traversing the internal network and accessing data on multiple hosts without escalating privileges, which is exactly what horizontal movement describes.

The other options don’t fit as neatly. Moving through the network at the same privilege level but focusing only on data available at that level can be vague about crossing to other machines. Privilege escalation on the initial host to obtain administrative access on the next system describes vertical movement, not horizontal. Targeting external services avoids internal lateral movement altogether.