Techniques of Social Engineering

In individual exploitation, social engineering is the act of manipulating people into performing actions or divulging confidential information. While similar to a confidence trick or simple fraud, the term typically applies to trickery or deception for the purpose of information gathering, fraud, or computer system access; in most cases the attacker never comes face-to-face with the victim.
All social engineering techniques are based on specific attributes of human decision-making known as cognitive biases. These biases, sometimes called "bugs in the human hardware," are exploited in various combinations to create attack techniques, some of which are listed here:

1. Pretexting is the act of creating and using an invented scenario (the pretext) to persuade a targeted victim to release information or perform an action and is typically done over the telephone. It is more than a simple lie as it most often involves some prior research or set up and the use of pieces of known information (e.g. for impersonation: date of birth, Social Security Number, last bill amount) to establish legitimacy in the mind of the target.
2. Phishing is a technique of fraudulently obtaining private information. Typically, the phisher sends an e-mail that appears to come from a legitimate business—a bank, or credit card company—requesting "verification" of information and warning of some dire consequence if it is not provided. The e-mail usually contains a link to a fraudulent web page that seems legitimate—with company logos and content—and has a form requesting everything from a home address to an ATM card's PIN.
3. This technique uses a rogue Interactive voice response (IVR) system to recreate a legitimate sounding copy of a bank or other institution's IVR system. The victim is prompted (typically via a phishing e-mail) to call in to the "bank" via a (ideally toll free) number provided in order to "verify" information. A typical system will reject log-ins continually, ensuring the victim enters PINs or passwords multiple times, often disclosing several different passwords. More advanced systems transfer the victim to the attacker posing as a customer service agent for further questioning.
4. Baiting is like the real-world Trojan Horse that uses physical media and relies on the curiosity or greed of the victim. In this attack, the attacker leaves a malware infected floppy disk, CD ROM, or USB flash drive in a location sure to be found (bathroom, elevator, sidewalk, parking lot), gives it a legitimate looking and curiosity-piquing label, and simply waits for the victim to use the device.
5. Quid pro quo means something for something. An attacker calls random numbers at a company claiming to be calling back from technical support. In a 2003 information security survey, 90% of office workers gave researchers what they claimed was their password in answer to a survey question in exchange for a cheap pen. Similar surveys in later years obtained similar results using chocolates and other cheap lures, although they made no attempt to validate the passwords.
6. Other types. Common confidence tricksters or fraudsters also could be considered "social engineers" in the wider sense, in that they deliberately deceive and manipulate people, exploiting human weaknesses to obtain personal benefit. They may, for example, use social engineering techniques as part of an IT fraud. The latest type of social engineering techniques include spoofing or hacking IDs of people having popular e-mail IDs such as Yahoo, Gmail, Hotmail, etc