Saturday, October 15, 2011

Know about Card Skimming and how to protect your card

Of late there are many reports about frauds related to  Credit/Debit/ATM cards. In many instances it is reported that the card details were obtained by the  fraudsters  using a technique called "Skimming". 

In this article, the modus operandi of skimming and the precautionary steps to be taken by the card holders are given for the benefit of card users.

What is Card Skimming?

Skimming is the unauthorised copying of information stored on the magnetic strip of a credit/debit/atm card.  It is typically an "inside job" by a dishonest employee of a legitimate merchant. The dishonest employee usually procures a victim's  card number using basic methods such as photocopying receipts or more advanced methods such as using a small electronic device (skimmer) to swipe and store hundreds of victims’ credit card numbers

The employee  sells the information through a contact or on the Internet, at which point counterfeit cards with your details on it are made. The criminals go on a shopping spree with a copy of the credit or debit card, and cardholders are unaware of the fraud until a statement arrives with purchases they did not make. 

Watch this video(from Youtube) on Credit card Skimming operations:

Skimming of ATM cards:

Instances of skimming have been reported where the perpetrator has put a device over the card slot of an ATM (automated teller machine), which reads the magnetic strip as the user unknowingly passes their card through it. 

These devices are often used in conjunction with a miniature camera (inconspicuously attached to the ATM) to read the user's PIN at the same time. This method is being used very frequently in many parts of the world, including South America, e.g. in Argentina and Europe, e.g. in the Netherlands 

Another technique used is a keypad overlay that matches up with the buttons of the legitimate keypad below it and presses them when operated, but records or transmits the keylog of the PIN entered by wireless. 

The device or group of devices illicitly installed on an ATM are also colloquially known as a "skimmer". Recently-made ATMs now often run a picture of what the slot and keypad are supposed to look like as a background, so that consumers can identify foreign devices attached. (Source:

Preventive steps to avoid fraud by skimming:

  • If you are in a restaurant or in a shop and the assistant wants to swipe your card out of your sight, or in a second machine, you should ask for your card back straight away and either pay with a cheque or cash, or not make the purchase.
  • Keep your credit card and ATM cards safe. Do not share your personal identity number (PIN) with anyone. Do not keep any written copy of your PIN with the card.
  • Check your bank account and credit card statements when you get them. If you see a transaction you cannot explain, report it to your  bank.
  • Choose passwords that would be difficult for anyone else to guess and keep your password secret.
  • If you are using an ATM, take the time to check that there is nothing suspicious about the machine like an unusual gadget or camera .If the ATM looks suspicious, do not use it and alert the bank which owns the ATM.



  1. more than skimming, if i am using an atm on the road side and someone robs it, thats it :) all gone :)

    very well written and thanks for sharing the information...

  2. Divya Ranjith and The BluntBlogger:Thank you for your comments

  3. Thank u Sujatha for your nice comments. There are many cases where people have lost money due to skimming. More awareness in Information Security is required among users of computers and cards when carrying out financial transactions.