Tuesday, April 1, 2008

Only an Ungullible You Can Prevent Phishing

As I mentioned in a previous entry, I'm a computer security specialist by day, so I've spent a fair amount of time noodling on ways to help protect people from hackers. In particular, one problem that has become an escalating game of cat-and-mouse between hackers and banks is phishing. Phishing is when an email (or website, or voicemail system) claims to be a trusted source, such as your bank, and asks you to provide sensitive information - only it's not your bank - it's the bad guys - and you just gave them your online banking password. Doh!

Phishing results in thousands of stolen identities daily, and it erodes the trust that customers have in online banking. So banks are constantly adding new security technology to make these attacks more difficult, but phishers are constantly coming up
"Banks will never 100% solve the
phishing problem...
because it's
not a technology problem."
with more clever ways to get around these controls. Will it ever end? Should you wait for your bank to solve this problem before you venture into online banking? I can tell you with absolute certainty that, no, banks will never 100% solve the phishing problem. Never ever! Why? Because it's not a technology problem, so there is no technology solution. Phishing is not a new problem - it's a new spin on an old problem - con games. And "con" is short for confidence, which means that phishers only need to trick people into being confident that they are communicating with their bank, when in fact they aren't. And there are an infinite number of creative, non-technical ways of playing such tricks.

So how can you protect yourself? Should you just give up and avoid the internet? Well to borrow a phrase from the 1970's Smokey the Bear, "Only an Ungullible You can prevent phishing." But how do we learn to be ungullible to phishing? If the phishers are so clever at coming up with new tricks, is there any hope that we can outsmart them? I believe it is possible with just three simple rules, but before I explain, let's start with a simple example of how phishing works.

Please complete the following sample exercise before continuing to Part II of this blog. In a real phishing attack, the phisher might pretend to be your bank and ask you to confirm your identity by providing your full credit card number. In this example, we are only asking for part of a real card number to make the example safe.

Phishing Exercise #1

Name of Issuing Bank:
Last 4 digits: ---
Card Type: -Visa -MasterCard -Discover -American Express

Note: It is safe to use a real credit card in this example because...

  • You are only giving part of your credit card #, not all of it

  • There is no Submit button, so you aren't sending your data anywhere

  • You may provide fake data if you still prefer, although some lessons from the example may not be as clear

After filling in the above example Phishing form, Click Here to continue with the rest of this blog...



1 comments:

Will Stranathan said...

Also, by knowing the issuing bank, the card type, and the last four numbers, when you do the checksum, you're down to 10^6 possibilities for the remaining digits (the checksum effectively reduces the keyspace by one power of 10. Most banks will put you at 5 digits, and you've got the last four.)