Using a heuristic system to detect an anomaly in a computer’s baseline, a system administrator
was able to detect an attack even though the company signature based IDS and antivirus did not
detect it. Further analysis revealed that the attacker had downloaded an executable file onto the
company PC from the USB port, and executed it to trigger a privilege escalation flaw.
Which of the following attacks has MOST likely occurred?

A.
Cookie stealing

B.
Zero-day

C.
Directory traversal

D.
XML injection

Explanation:
The vulnerability was unknown in that the IDS and antivirus did not detect it. This is zero day
vulnerability.
A zero day vulnerability refers to a hole in software that is unknown to the vendor. This security
hole is then exploited by hackers before the vendor becomes aware and hurries to fix it—this
exploit is called a zero day attack. Uses of zero day attacks can include infiltrating malware,
spyware or allowing unwanted access to user information. The term “zero day” refers to the
unknown nature of the hole to those outside of the hackers, specifically, the developers. Once the

vulnerability becomes known, a race begins for the developer, who must protect users.