Which would be considered an active information gathering technique?

An active information gathering technique involves proactively engaging with a system or network to extract information and understand its structure or vulnerabilities. Conducting zone transfers fits this definition perfectly. A zone transfer is a type of DNS (Domain Name System) transfer where a copy of DNS records is shared between DNS servers. By executing a zone transfer, a security analyst can retrieve a comprehensive list of subdomains, IP addresses, and other valuable information about a target's network configuration. This technique is not passive, as it actively requests and retrieves data directly from the server.

In contrast, the other options—monitoring social media mentions, accessing archived website information, and reviewing company press releases—are all passive techniques. These methods involve gathering information that is already publicly available without interacting directly with the target system or network. They do not provide the same level of detail or specificity about the internal workings of the organization's infrastructure as an active technique like a zone transfer does.