Replay Attacks & Malicious Code

Question 1

Replay Attack

Answer 1

Replay attack → attack where valid captured data such as authentication messages or session tokens are recorded and resent later to gain unauthorized access, often performed using network taps, address resolution protocol poisoning, or malware on the victim’s system.

Question 2

Pass the Hash

Answer 2

Pass the hash → attack technique where an attacker uses a stolen password hash to authenticate without knowing the actual plaintext password, commonly seen in Windows authentication environments.

Question 3

Browser Cookie & Session IDs

Answer 3

Browser cookies and session identifiers → small data values stored by browsers that maintain authenticated sessions, which become high-value targets because stealing them can allow session hijacking.

Question 4

Session Hijacking

Answer 4

Session hijacking → also called sidejacking, attack where an attacker takes over an active user session by stealing session identifiers or cookies, allowing impersonation without reauthentication.

Question 5

Header Manipulation

Answer 5

Header manipulation → attack where an attacker alters Hypertext Transfer Protocol headers to bypass security controls, inject malicious data, or impersonate legitimate users.

Question 6

Malicious Code

Answer 6

Malicious code → any unauthorized code intentionally designed to cause harm, including malware, scripts, or injected instructions that compromise confidentiality, integrity, or availability.

Question 7

Privilege Escalation Attack

Answer 7

Privilege escalation attack → attack where an attacker gains higher-level permissions than originally authorized, often by exploiting software vulnerabilities or misconfigurations.

Question 8

Cross-site Request Attack

Answer 8

Cross-site request attack → attack that tricks a user’s browser into sending unintended requests to a trusted website while the user is authenticated, abusing session trust.

Question 9

XSRF

Answer 9

Cross-site request forgery (XSRF) → attack where malicious requests are sent from a user’s authenticated browser without their knowledge, often mitigated using tokens, proper authentication checks, and request validation.