Checklist For Protecting Your Credit Card Information Online

Kenneth M. Smith CISSP CISA QSA


I am an information security consultant and a PCI Qualified Security Assessor. I have worked with companies to help them lower their risk when it comes to protecting customer card data and personally identifiable information (PII). I have seen some pretty interesting things, some of which I would rather not share or will not share due to non-disclosure agreements. I will let you surmise what I mean by "interesting".

But an important part of the equation is consumer awareness and good practice when it comes to using credit cards, whether online or at retail establishments. Below is my first attempt at a checklist for consumers when using their credit cards to make purchases online. I assume that you are practicing basic safe computing by using a Firewall, Anti-virus, and Anti-Spyware software. There are 18 items and they are not in a specific order of importance.

Note: In a future installment I will provide a checklist specifically related to retail purchases as there are also plenty of steps you can take to protect yourself when visiting your local restaurant, gas station, or other retail establishment. Dealing with a case of card fraud and identity theft is also quite a chore, not nearly as easy as some might make it sound. I am also working on a checklist for dealing with such an event.

1. Avoid using your email address as your login name. Don’t use your email address as your login ID on web sites that you use your credit card to make purchases from. It’s a common practice now that web sites default to using your email address as the login name. This is for convenience and to help address the problem of users forgetting their login name. The problem is that if your login information is compromised on just one site, it could be assumed that you used not only the same login name (email address) but the same password too. Now all the attacker needs to do is to try this same login name and password on other sites.

2. Delete online accounts you no longer use. Remove your credit card information and your login account from sites you no longer frequent. It will only take a moment and it will reduce your exposure. If the site does not make this easy to do this online, call them or send them a letter with your request.

3. Change your password regularly. And I don’t mean once a year here. A reasonable time frame is probably every few months or even more frequently depending on your online buying habits. If the site does not make it easy to change the password, contact them for assistance on how to do this yourself online.

4. Use complex passwords. This goes without saying but I continue to be amazed when performing security audits at how many people use very simple passwords. Consider using passphrases instead of passwords and mix it up with numbers, upper and lower case letters, and other punctuation characters. If a web site doesn’t allow the use of characters other than numbers and letters in the password, complain! This just isn’t good security practice.

5. Don't log in using your SSN or account number. Do not log into sites using your full social security number or account number as the login ID or password. If any sites you use require this, contact them and demand that they change this practice. There is really no reason for this.

6. Perform initial web site registration for services that provide online access as a benefit. You likely have credit card, bank, medical, insurance, 401k, and other sites that make online access to your accounts possible as an additional benefit. You may not even be aware that you have online access to your account as a counterpart to your standard account management method. The first time sign-in to some sites may use a portion of your social security number or other personal information as part of the initial sign up confirmation process. If you don’t plan on using such sites, contact the company and request that they disable online access to the account. If you do plan on using the site, perform the initial login as soon as you can and assign a complex password to the account. Also, as mentioned above, avoid using your email address as your login name.

7. Read the security and privacy policies of web sites that you use for card transactions. A number of large well known sites clearly stipulate that they are not responsible if your account or data is compromised and that there is no expectation of security or privacy on their part. Most users of these sites are probably not aware of this. Consider the consequences of using such sites.

8. SSL doesn’t mean your data is secure or that the company follows best security practices. Don’t trust sites that have a security and privacy statement that simple says “this site is protected with the latest SSL security technology so your information is secure”. This really bugs me to see this as a security statement on a web site. SSL only protects your information in transit between your web browser and their web server during your session. This means nothing when it comes to protecting your information once it is saved to their server, or leaves their server to be processed or stored elsewhere. Read their policy on protecting your information after the transaction.

9. Don’t make online card transactions from an untrusted computer. This includes Kiosks, Internet Cafes, or even a friends computer. You just don’t know what might be running in the background capturing your transaction information.

10. Use online payment services. Use an online payment service to reduce the number of merchants that have your credit card numbers. These services reduce the possible ‘attack surface’ of your card information by keeping your credit card and identity information with the payment service, not with each of the merchants.

11. Don’t ignore warnings from your web browser. They appear for a reason and you should read them. Don’t get in the habit of clicking Ok or Cancel before you know what the warning is about. An error could be a sign of a malicious site redirect, man-in-the-middle, or phishing attack.

12. Use additional security features offered by the site. If the site offers additional security features, like those that confirm the authenticity of the site and the user computer, use them. They help ensure that you are connected to the actual site you intended, not a spoofed site.

13. Watch for the lock. You’ve probably been reminded of this hundreds of times. But it’s worth mentioning it again. If there is no lock, then the site is not using SSL. If the lock indicator does appear but it looks “broken” or there is a line across it, then there is a problem with the web sites SSL certificate. Click on the lock for more information about the problem.

14. Avoid logging in from the main page of web sites. There are some sites that provide login fields on their main web site page which are not initially secure (no lock displayed). This, they claim, is for user convenience. In most cases, the actual login will usually then be carried out encrypted with SSL, but not until you enter your login information and click login. This behavior is inconsistent with the idea of ensuring that the site is secure (you see the lock) before providing your login information. A simple workaround is to click on the login button without providing a login name and password. You will see a login error but you will immediately be redirected to a secure login page where you can login as usual.

15. Do not use the ‘remember me’ feature for sites in which you use credit cards. For many sites, this means that they will store a persistent ‘cookie’ on your computer so they will know it’s you the next time you connect to the site. If your system were to be compromised, that ‘cookie’ is all that’s needed to login to your account without a login name and password. Note that this is different than the new feature of some sites that let you 'register' a computer as a system that you normally use to login. Also, after an online card transaction, remember to always click on the “log out” button and then close the browser window.

16. Do not use a debit card for online purchases. Most credit cards provide some form of protection in case fraud were to occur. For example, you are usually not liable for any fraudulent purchases if you notify the card company quickly. But you don't normally get these protections and liability limits if you use one of the many types of debit cards available that can also be used as if they were a credit card. They are not truly a credit card.

17. Check your credit report often. Many victims first learn of fraudulent accounts created on their behalf while reviewing their credit report. One of the tell-tale signs is a new address showing up in your credit report that is obviously not yours. At a minimum, you should be requesting your free credit reports from http://www.annualcreditreport.com/ or by phone at 1-877-322-8228 every 12 months.

18. Check your card statement as soon as it arrives. Many victims first learn that their card has been used fraudulently while reviewing their monthly statement. Be diligent and read it as soon as it arrives. Also, if you don't get your statement around the time it normally arrives, be concerned. Contact the card company to make sure the delay is on their end, and that someone didn't fraudulently change the address on the account.

Contents Copyright (c) 2007 Kenneth M. Smith