Securing Email with Cisco Email Security Appliance

A.

The correct answer is C. ^Alpha\ Beta$

Explanation:

Forged Email Detection is a feature in Cisco Email Security Appliance (ESA) that helps detect emails with forged or spoofed sender addresses. To accomplish this, ESA uses a content dictionary that includes a list of patterns or regular expressions that identify email addresses or domains that are commonly spoofed.

When creating a new content dictionary for Forged Email Detection, the analyst should add entries that match the patterns of the spoofed addresses or domains they want to detect. In this case, the entry that matches the pattern of the spoofed sender address is ^Alpha\ Beta$.

Let's break down this regular expression:

• The ^ symbol at the beginning indicates the start of the string.
• Alpha\ Beta matches the literal text "Alpha Beta", but the backslash () character is used to escape the space between the words. This is necessary because spaces are used as delimiters in regular expressions.
• The $ symbol at the end indicates the end of the string.

Therefore, this regular expression matches exactly the string "Alpha Beta" and nothing else. It will help detect emails where the sender address has been forged to appear as "Alpha Beta".

Option A, mycompany.com, is not a regular expression and will not match any specific pattern of a forged email address.

Option B, Alpha Beta, is also not a regular expression and will not match any specific pattern of a forged email address. Moreover, it is too generic and may result in false positives.

Option D, Alpha.Beta@mycompany.com, is a specific email address and not a regular expression. It will only match if the forged sender address is exactly Alpha.Beta@mycompany.com, which is not likely in most cases.