What two conditions must a digital signature meet?

Initiating an attack against targeted businesses and organizations, threat actors compromise a carefully selected website by inserting an exploit resulting in malware infection. The attackers run exploits on well-known and trusted sites likely to be visited by their targeted victims. Aside from carefully choosing sites to compromise, these attacks are known to incorporate zero-day exploits that target unpatched vulnerabilities. Thus, the targeted entities are left with little or no defense against these exploits.
What type of attack is outlined in the scenario?

Under the "Post-attack Phase and Activities", it is the responsibility of the tester to restore the systems to a pre-test state.
Which of the following activities should not be included in this phase? (see exhibit) Exhibit:

You are tasked to perform a penetration test. While you are performing information gathering, you find an employee list in Google. You find the receptionist's email, and you send her an email changing the source email to her boss's email( boss@company ). In this email, you ask for a pdf with information. She reads your email and sends back a pdf with links. You exchange the pdf links with your malicious links (these links contain malware) and send back the modified pdf, saying that the links don't work. She reads your email, opens the links, and her machine gets infected. You now have access to the company network.
What testing method did you use?

Bob learned that his username and password for a popular game has been compromised. He contacts the
company and resets all the information. The company suggests he use two-factor authentication; which
option below offers that?