Entries Tagged "phishing"

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Huge Online Bank Heist

Wow:

Swedish bank Nordea has told ZDNet UK that it has been stung for between seven and eight million Swedish krona — up to £580,000 — in what security company McAfee is describing as the “biggest ever” online bank heist.

Over the last 15 months, Nordea customers have been targeted by emails containing a tailormade Trojan, said the bank.

Nordea believes that 250 customers have been affected by the fraud, after falling victim to phishing emails containing the Trojan. According to McAfee, Swedish police believe Russian organised criminals are behind the attacks. Currently, 121 people are suspected of being involved.

This is my favorite line:

Ehlin blamed successful social engineering for the heist, rather than any deficiencies in Nordea security procedures.

Um…hello? Are you an idiot, or what?

Posted on January 23, 2007 at 12:54 PMView Comments

Microsoft Anti-Phishing and Small Businesses

Microsoft has a new anti-phishing service in Internet Explorer 7 that will turn the address bar green and display the website owner’s identity when surfers visit on-line merchants previously approved as legitimate. So far, so good. But the service is only available to corporations: not to sole proprietorships, partnerships, or individuals.

Of course, if a merchant’s bar doesn’t turn green it doesn’t mean that they’re bad. It’ll be white, which indicates “no information.” There are also yellow and red indications, corresponding to “suspicious” and “known fraudulent site.” But small businesses are worried that customers will be afraid to buy from non-green sites.

That’s possible, but it’s more likely that users will learn that the marker isn’t reliable and start to ignore it.

Any white-list system like this has two sources of error. False positives, where phishers get the marker. And false negatives, where legitimate honest merchants don’t. Any system like this has to effectively deal with both.

EDITED TO ADD (12/21): Research paper: “Phinding Phish: An Evaulation of Anti-Phishing Toolbars,” by L. Cranor, S. Egleman, J. Hong, and Y. Zhang.

Posted on December 21, 2006 at 6:58 AMView Comments

Fighting Fraudulent Transactions

Last March I wrote that two-factor authentication isn’t going to reduce financial fraud or identity theft, that all it will do is force the criminals to change their tactics:

Unfortunately, the nature of attacks has changed over those two decades. Back then, the threats were all passive: eavesdropping and offline password guessing. Today, the threats are more active: phishing and Trojan horses.

Here are two new active attacks we’re starting to see:

  • Man-in-the-Middle attack. An attacker puts up a fake bank website and entices user to that website. User types in his password, and the attacker in turn uses it to access the bank’s real website. Done right, the user will never realize that he isn’t at the bank’s website. Then the attacker either disconnects the user and makes any fraudulent transactions he wants, or passes along the user’s banking transactions while making his own transactions at the same time.
  • Trojan attack. Attacker gets Trojan installed on user’s computer. When user logs into his bank’s website, the attacker piggybacks on that session via the Trojan to make any fraudulent transaction he wants.

See how two-factor authentication doesn’t solve anything? In the first case, the attacker can pass the ever-changing part of the password to the bank along with the never-changing part. And in the second case, the attacker is relying on the user to log in.

The solution is not to better authenticate the person, but to authenticate the transaction. (Think credit cards. No one checks your signature. They really don’t care if you’re you. They maintain security by authenticating the transactions.)

Of course, no one listens to me. U.S. regulators required banks to implement two-factor authentication by the end of this year. But customers are rebelling, and banks are scrambling to figure out something — anything — else. And, amazingly enough and purely by accident it seems, they’ve stumbled on security solutions that actually work:

Instead, to comply with new banking regulations and stem phishing losses, banks and the vendors who serve them are hurriedly putting together multipronged strategies that they say amount to “strong” authentication. The emerging approach generally consists of somehow recognizing a customer’s computer, asking additional challenge questions for risky behavior and putting in place back-end fraud detection.

[…]

Despite the FFIEC guidance about authentication, the emerging technologies that actually seem to hold the most promise for protecting the funds in consumer banking accounts aren’t authentication systems at all. They’re back-end systems that monitor for suspicious behavior.

Some of these tools are rule-based: If a customer from Nebraska signs on from, say, Romania, the bank can determine that the log-on always be considered suspect. Others are based on a risk score: That log-on from Romania would add points to a risk score, and when the score reaches a certain threshold, the bank takes action.

Flagged transactions can get bumped to second-factor authentication — usually, a call on the telephone, something the user has. This has long been done manually in the credit card world. Just think about the last phone call you got from your credit card company’s fraud department when you (or someone else) tried to make a large purchase with your credit card in Europe. Some banks, including Washington Mutual, are in the process of automating out-of-band phone calls for risky online transactions.

Exactly. That’s how you do it.

EDITED TO ADD (12/6): Another example.

Posted on November 27, 2006 at 6:07 AMView Comments

Targeted Trojan Horses Are the Future of Malware

Good article:

Security technology can stop common attacks, but targeted attacks fly under the radar. That’s because traditional products, which scan e-mail at the network gateway or on the desktop, can’t recognize the threat. Alarm bells will ring if a new attack targets thousands of people or more, but not if just a handful of e-mails laden with a new Trojan horse is sent.

“It is very much sweeping in under the radar,” said Graham Cluley, a senior technology consultant at Sophos, a U.K.-based antivirus company. If it is a big attack, security companies would know something is up, because it hits their customers’ systems and their own honeypots (traps set up to catch new and existing threats), he said.

Targeted attacks are, at most, a blip on the radar in the big scheme of security problems, researchers said. MessageLabs pulls about 3 million pieces of malicious software out of e-mail messages every day. Only seven of those can be classified as a targeted Trojan attack, said Alex Shipp, a senior antivirus technologist at the e-mail security company.

“A typical targeted attack will consist of between one and 10 similar e-mails directed at between one and three organizations,” Shipp said. “By far the most common form of attack is to send just one e-mail to one organization.”

Posted on October 17, 2006 at 7:04 AMView Comments

PhishTank

PhishTank went live this week:

PhishTank is a collaborative clearing house for data and information about phishing on the Internet. Also, PhishTank provides an open API for developers and researchers to integrate anti-phishing data into their applications at no charge.

It’s run by OpenDNS.

Posted on October 5, 2006 at 6:40 AMView Comments

Bot Networks

What could you do if you controlled a network of thousands of computers — or, at least, could use the spare processor cycles on those machines? You could perform massively parallel computations: model nuclear explosions or global weather patterns, factor large numbers or find Mersenne primes, or break cryptographic problems.

All of these are legitimate applications. And you can visit distributed.net and download software that allows you to donate your spare computer cycles to some of these projects. (You can help search for Optimal Golomb Rulers — even if you have no idea what they are.) You’ve got a lot of cycles to spare. There’s no reason that your computer can’t help search for extraterrestrial life as it, for example, sits idly waiting for you to read this essay.

The reason these things work is that they are consensual; none of these projects download software onto your computer without your knowledge. None of these projects control your computer without your consent. But there are lots of software programs that do just that.

The term used for a computer remotely controlled by someone else is a “bot”. A group of computers — thousands or even millions — controlled by someone else is a bot network. Estimates are that millions of computers on the internet today are part of bot networks, and the largest bot networks have over 1.5 million machines.

Initially, bot networks were used for just one thing: denial-of-service attacks. Hackers would use them against each other, fighting hacker feuds in cyberspace by attacking each other’s computers. The first widely publicized use of a distributed intruder tool — technically not a botnet, but practically the same thing — was in February 2000, when Canadian hacker Mafiaboy directed an army of compromised computers to flood CNN.com, Amazon.com, eBay, Dell Computer and other sites with debilitating volumes of traffic. Every newspaper carried that story.

These days, bot networks are more likely to be controlled by criminals than by hackers. The important difference is the motive: profit. Networks are being used to send phishing e-mails and other spam. They’re being used for click fraud. They’re being used as an extortion tool: Pay up or we’ll DDoS you!

Mostly, they’re being used to collect personal data for fraud — commonly called “identity theft.” Modern bot software doesn’t just attack other computers; it attacks its hosts as well. The malware is packed with keystroke loggers to steal passwords and account numbers. In fact, many bots automatically hunt for financial information, and some botnets have been built solely for this purpose — to gather credit card numbers, online banking passwords, PayPal accounts, and so on, from compromised hosts.

Swindlers are also using bot networks for click fraud. Google’s anti-fraud systems are sophisticated enough to detect thousands of clicks by one computer; it’s much harder to determine if a single click by each of thousands of computers is fraud, or just popularity.

And, of course, most bots constantly search for other computers that can be infected and added to the bot network. (A 1.5 million-node bot network was discovered in the Netherlands last year. The command-and-control system was dismantled, but some of the bots are still active, infecting other computers and adding them to this defunct network.)

Modern bot networks are remotely upgradeable, so the operators can add new functionality to the bots at any time, or switch from one bot program to another. Bot authors regularly upgrade their botnets during development, or to evade detection by anti-virus and malware cleanup tools.

One application of bot networks that we haven’t seen all that much of is to launch a fast-spreading worm. (Some believe the Witty worm spread this way.) Much has been written about “flash worms” that can saturate the internet in 15 minutes or less. The situation gets even worse if 10 thousand bots synchronize their watches and release the worm at exactly the same time. Why haven’t we seen more of this? My guess is because there isn’t any profit in it.

There’s no real solution to the botnet problem, because there’s no single problem. There are many different bot networks, controlled in many different ways, consisting of computers infected through many different vulnerabilities. Really, a bot network is nothing more than an attacker taking advantage of 1) one or more software vulnerabilities, and 2) the economies of scale that computer networks bring. It’s the same thing as distributed.net or SETI@home, only the attacker doesn’t ask your permission first.

As long as networked computers have vulnerabilities — and that’ll be for the foreseeable future — there’ll be bot networks. It’s a natural side-effect of a computer network with bugs.

This essay originally appeared on Wired.com.

EDITED TO ADD (7/27): DDOS extortion is a bigger problem than you might think. Right now it’s primarily targeted against fringe industries — online gaming, online gambling, online porn — located offshore, but we’re seeing more and more of against mainstream companies in the U.S. and Europe.

EDITED TO ADD (7/27): Seems that Witty was definitely not seeded from a bot network.

Posted on July 27, 2006 at 6:35 AMView Comments

Firefox 2.0 to Contain Anti-Phishing Features

This is a good idea.

The built anti-phishing capability warns users when they come across Web forgeries, and offers to return the user to his or her home page. Meanwhile, microsummaries are regularly updated summaries of Web pages, small enough to fit in the space available to a bookmark label, but large enough to provide more useful information about pages than static page titles, and are regularly updated as new information becomes available.

Posted on July 21, 2006 at 12:55 PMView Comments

Failure of Two-Factor Authentication

Here’s a report of phishers defeating two-factor authentication using a man-in-the-middle attack.

The site asks for your user name and password, as well as the token-generated key. If you visit the site and enter bogus information to test whether the site is legit — a tactic used by some security-savvy people — you might be fooled. That’s because this site acts as the “man in the middle” — it submits data provided by the user to the actual Citibusiness login site. If that data generates an error, so does the phishing site, thus making it look more real.

I predicted this last year.

Posted on July 12, 2006 at 7:31 AMView Comments

Why Phishing Works

Interesting paper.

Abstract:

To build systems shielding users from fraudulent (or phishing) websites, designers need to know which attack strategies work and why. This paper provides the first empirical evidence about which malicious strategies are successful at deceiving general users. We first analyzed a large set of captured phishing attacks and developed a set of hypotheses about why these strategies might work. We then assessed these hypotheses with a usability study in which 22 participants were shown 20 web sites and asked to determine which ones were fraudulent. We found that 23% of the participants did not look at browser-based cues such as the address bar, status bar and the security indicators, leading to incorrect choices 40% of the time. We also found that some visual deception attacks can fool even the most sophisticated users. These results illustrate that standard security indicators are not effective for a substantial fraction of users, and suggest that alternative approaches are needed.

Here’s an article on the paper.

Posted on April 4, 2006 at 2:18 PMView Comments

Sidebar photo of Bruce Schneier by Joe MacInnis.