What is Vishing?

Vishing is the practice of using social engineering over the telephone system with the purpose of stealing sensitive financial information or other sensitive personal data from a victim. Vishing is one of the most serious threats today and is widely perpetrated by criminals.

The word “vishing” is a combination of two words “voice” and “phishing”. In this technique, attackers use the telephone system to do phishing and hence the name.

Vishing is typically used by criminals to steal sensitive banking information like account number, PIN, password, OTP, and credit card numbers. Attackers can also steal other personal details of users and exploit that to perpetrate identity theft.

Attackers often use VoIP and an automated system like IVR to perpetrate vishing. They may even use techniques like War Dialing and Caller ID Spoofing to serve their purpose.

 

What is War Dialing?

Attackers often use war dialing to harvest phone numbers of potential victims. It is a technique to automatically scan a list of telephone numbers in a particular region. Attackers often use dedicated software to dial all numbers in a local area one by one. As soon as they get a response from any number, they simply note it down so that they can later use it for vishing.

 

What is Caller ID Spoofing?

Attackers often use Caller ID Spoofing to deceive a victim in vishing. They mask the actual caller telephone number and a different deceiving number appears in the receiver of the victim.

Attackers can use a variety of methods and different technologies for that purpose. In the past, Caller ID Spoofing would require a piece of advanced knowledge, but nowadays attackers often use VoIP or PRI lines to do that easily. For example, some VoIP providers give a user the option to configure the displayed number. This has lots of legitimate uses also. For example, a doctor may want to answer a patient from his home, but he may not want to reveal his home phone number at the same time. But, attackers often use this technique to hide their identity and impersonate others.

 

How does Vishing work?

Attackers may perpetrate vishing as mentioned below.

  • Criminals first harvest phone numbers of potential victims. They may use several techniques for that purpose. They may steal phone numbers from an institution or they may use war dialing to find out valid phone numbers.
  • The criminals then start making calls to potential victims. They usually use Caller ID Spoofing to deceive the victims and hide their identity.
  • In a vishing call, the attackers may trick a user in revealing sensitive financial details. They may say the call is from a bank and there is a problem with the user’s bank account or credit/debit card and the user needs to give his financial details to the caller in order to address the problem. The attackers may also use automated instructions to ask the victim to type in his credit card number, account number or PIN on the keypad. And, in some cases, the attackers ask the victim for his personal details so that the attackers can later use that to impersonate the victim for fraudulent purposes.

 

A real-life example of Vishing

A widely perpetrated vishing scam is Microsoft tech support scam. In this scam, the attackers …

Facebooktwitterredditpinterestlinkedinmail

Calculate the pseudoinverse of a matrix using Python

What is the pseudoinverse of a matrix? We know that if A is a square matrix with full rank, then A-1 is said to be the inverse of A if the following condition holds: $latex AA^{-1}=A^{-1}A=I $ The pseudoinverse or the Moore-Penrose inverse of a matrix is a...

Cholesky decomposition using Python

What is Cholesky decomposition? A square matrix A is said to have Cholesky decomposition if it can be written as a product of a lower triangular matrix and its conjugate transpose. $latex A=LL^{*} $ If all the entries of A are real numbers, then the conjugate...

Tensor Hadamard Product using Python

In one of our previous articles, we already discussed what the Hadamard product in linear algebra is. We discussed that if A and B are two matrices of size mxn, then the Hadamard product of A and B is another mxn matrix C such that: $latex H_{i,j}=A_{i,j} \times...

Perform tensor addition and subtraction using Python

We can use numpy nd-array to create a tensor in Python. We can use the following Python code to perform tensor addition and subtraction. import numpy A = numpy.random.randint(low=1, high=10, size=(3, 3, 3)) B = numpy.random.randint(low=1, high=10, size=(3, 3, 3)) C =...

How to create a tensor using Python?

What is a tensor? A tensor is a generalization of vectors and matrices. It is easily understood as a multidimensional array. For example, in machine learning, we can organize data in an m-way array and refer it as a data tensor. Data related to images, sounds, movies,...

How to combine NumPy arrays using horizontal stack?

We can use the hstack() function from the numpy module to combine two or more NumPy arrays horizontally. For example, we can use the following Python code to combine three NumPy arrays horizontally. import numpy A = numpy.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]]) B =...

How to combine NumPy arrays using vertical stack?

Let’s say we have two or more NumPy arrays. We can combine these NumPy arrays vertically using the vstack() function from the numpy module. For example, we can use the following Python code to combine three NumPy arrays vertically. import numpy A = numpy.array([[1, 2,...

Singular Value Decomposition (SVD) using Python

What is Singular Value Decomposition (SVD)? Let A be an mxn rectangular matrix. Using Singular Value Decomposition (SVD), we can decompose the matrix A in the following way: $latex A_{m \times n}=U_{m \times m}S_{m \times n}V_{n \times n}^T $ Here, U is an mxm matrix....

Eigen decomposition of a square matrix using Python

Let A be a square matrix. Let’s say A has k eigenvalues λ1, λ2, ... λk. And the corresponding eigenvectors are X1, X2, ... Xk. $latex X_1=\begin{bmatrix} x_{11} \\ x_{21} \\ x_{31} \\ ... \\ x_{k1} \end{bmatrix} \\ X_2=\begin{bmatrix} x_{12} \\ x_{22} \\ x_{32} \\ ......

How to calculate eigenvalues and eigenvectors using Python?

In our previous article, we discussed what eigen values and eigenvectors of a square matrix are and how we can calculate the eigenvalues and eigenvectors of a square matrix mathematically. We discussed that if A is a square matrix, then $latex (A- \lambda I) \vec{u}=0...

Amrita Mitra

Author

Ms. Amrita Mitra is an author, who has authored the books “Cryptography And Public Key Infrastructure“, “Web Application Vulnerabilities And Prevention“, “A Guide To Cyber Security” and “Phishing: Detection, Analysis And Prevention“. She is also the founder of Asigosec Technologies, the company that owns The Security Buddy.

0 Comments

Submit a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Not a premium member yet?

Please follow the link below to buy The Security Buddy Premium Membership.

Featured Posts

Translate »