A Trojan, or Trojan horse, is a type of malware that disguises itself as a legitimate, harmless program or file to trick users into downloading and installing it. Once activated, a Trojan can perform a range of malicious activities, including giving attackers unauthorized access to the infected system. This can lead to the theft of sensitive information, such as credit card numbers and passwords, and can also allow the attacker to install additional malware, potentially leading to further damage, such as the erasure of data. Unlike viruses and worms, Trojans do not replicate themselves but rely on the deception of users to spread.
References:The Incident Handler (ECIH v3) course materials cover various types of malware, including Trojans, and their characteristics. The curriculum emphasizes the importance of understanding how different types of malicious software operate to effectively manage and respond to security incidents involving such threats.

Pharming is a cyber attack intended to redirect a website's traffic to another, bogus website. By poisoning a DNS server's cache, attackers can redirect users from the site they intended to visit to one that is malicious, without the user's knowledge or any action on their part, such as clicking a deceptive link. This technique is particularly insidious because it can affect well-intentioned users who type the correct URL into their browsers but are still redirected. War driving involves searching for wireless networks from a moving vehicle, skimming refers to stealing credit card information using a device placed on ATMs or point-of-sale terminals, and pretexting is a form of social engineering where the attacker lies to obtain privileged data.References:The Incident Handler (ECIH v3) certification program covers a variety of cyber attacks and techniques, including DNS poisoning and pharming, explaining how attackers exploit vulnerabilities to redirect users to fraudulent sites.