What cybersecurity attack monitors data traveling across a network?

The cybersecurity attack that involves monitoring data traveling across a network is known as sniffing. Sniffing is typically conducted using software tools called packet sniffers, which capture and analyze packets of data as they travel through the network. This type of attack can be used to gather sensitive information, such as usernames, passwords, and other confidential data.

By intercepting and examining the data packets, an attacker can understand the communication patterns and potentially exploit the information for various malicious purposes. Sniffing can be particularly effective in unsecured networks, such as public Wi-Fi, where data may not be encrypted.

In contrast, packet tampering involves altering the data packets themselves, rather than merely observing them. Ransomware is a type of malicious software that encrypts files and demands payment for their release, while malware is a broader category of malicious software that can include a variety of attacks but does not specifically focus on monitoring network data traffic. Thus, sniffing is the correct answer as it directly pertains to the act of monitoring data traveling across a network.