The Art of Deception: Controlling the Human Element of Security (9 page)

That meant I'd have to trick the guy into telling me his username and password. For that, I'd wait until the weekend. 70 You already know the rest. On Saturday I called Cramer and walked him through a ruse about a worm and the servers having to be restored from backup to overcome his suspicions.

What about the story I told him, the one about listing a password when he filled out his employee papers? I was counting on him not remembering that had never happened. A new employee fills out so many forms that, years later, who would remember? And anyway, if I had struck out with him, I still had that long list of other names.

With his username and password, I got into the server, fished around for a little while, and then located the design files for the STH-100. I wasn't exactly sure which ones were key, so I just transferred all the files to a dead drop, a free FTP site in China, where they could be stored without anybody getting suspicious. Let the client sort through the junk and find what he wants. LINGO DEAD DROP A place for leaving information where it is unlikely to be found by others. In the world of traditional spies, this might be behind a loose stone in a wall; in the world of the computer hacker, it's commonly an Internet site in a remote country.

Analyzing the Con For the man we're calling Craig Cogburne, or anyone like him equally skilled in the larcenous-but-not-always-illegal arts of social engineering, the challenge presented here was almost routine. His goal was to locate and download files stored on a secure corporate computer, protected by a firewall and all the usual security technologies.

Most of his work was as easy as catching rainwater in a barrel. He began by posing as somebody from the mail room and furnished an added sense of urgency by claiming there was a FedEx package waiting to be delivered. This deception produced the name of the team leader for the heart-stent engineering group, who was on vacation, but - convenient for any social engineer trying to steal information - he had helpfully left the name and phone number of his assistant. Calling her, Craig defused any suspicions by claiming that he was responding to a request from the team leader. With the team leader out of town, Michelle had no way to verify his claim. She accepted it as the truth and had no problem providing a list of people in the group - for Craig, a necessary and highly prized set of information.

She didn't even get suspicious when Craig wanted the list sent by fax instead of by email, ordinarily more convenient on both ends. Why was she so gullible? Like many employees, she didn't want her boss to return to town and find she had stonewalled a caller who was just trying to do something the boss had asked him for. Besides, the caller said that the boss had not just authorized the request, but asked for his assistance. Once again, here's an example of someone displaying the strong desire to be a team player, which makes most people susceptible to deception.

Craig avoided the risk of physically entering the building simply by having the fax sent to the receptionist, knowing she was likely to be helpful. Receptionists are, after all, usually chosen for their charming personalities and their ability to make a good impression. Doing small favors like receiving a fax and sending it on comes with the receptionist's territory, a fact that Craig was able to take advantage of. What she was ending out happened to be information that might have raised alarm bells with anyone knowing the value of the information - but how could receptionist be expected to know which information is benign and which sensitive? Using a different style of manipulation, Craig acted confused and na�ve to convince the guy in computer operations to provide him with the dial up access number to the company's terminal server, the hardware used as a connection point to other computer systems within the internal network.

MITNICK MESSAGE Everybody's first priority at work is to get the job done. Under that pressure, security practices often take second place and are overlooked or ignored. Social engineers rely on this when practicing their craft.

Craig was able to connect easily by trying a default password that had never been changed, one of the glaring, wide-open gaps that exist throughout many internal networks that rely on firewall security. In fact, the default passwords for many operating systems, routers, and other types of products, including PBXs, are made available on line. Any social engineer, hacker, or industrial spy, as well as the just plain curious, can find the list at http://www.phenoelit.de/dpl/dpl.html. (It's absolutely incredible how easy the Internet makes life for those who know where to look. And now you know, too.)

Cogburne then actually managed to convince a cautious, suspicious man ("What did you say your last name was? Who's your supervisor?") to divulge his username and password so that he could access servers used by the heart-stent development team. This was like leaving Craig with an open door to browse the company's most closely guarded secrets and download the plans for the new product. What if Steve Cramer had continued to be suspicious about Craig's call? It was unlikely he would do anything about reporting his suspicions until he showed up at work on Monday morning, which would have been too late to prevent the attack.

One key to the last part of the ruse: Craig at first made himself sound lackadaisical and uninterested in Steve's concerns, then changed his tune and sounded as if he was trying to help so Steve could get his work done. Most of the time, if the victim believes you're trying to help him or do him some kind of favor, he will part with confidential information that he would have otherwise protected carefully.

PREVENTING THE CON One of the most powerful tricks of the social engineer involves turning the tables. That's what you've seen in this chapter. The social engineer creates the problem, and then magically solves the problem, deceiving the victim into providing access to the company's most guarded secrets. Would your employees fall for this type of ruse? Have you bothered to draft and distribute specific security rules that could help to prevent it?

Educate, Educate, and Educate... There's an old story about a visitor to New York who stops a man on the street and asks, "How do I get to Carnegie Hall?" The man answers, "Practice, practice, practice." Everyone is so vulnerable to social engineering attacks that a company's only effective defense is to educate and train your people, giving them the practice they need to spot a social engineer. And then keep reminding people on a consistent basis of what they learned in the training, but are all too apt to forget.

Everyone in the organization must be trained to exercise an appropriate degree of suspicion and caution when contacted by someone he or she doesn't personally know, especially when that someone is asking for any sort of access to a computer or network. It's human nature to want to trust others, but as the Japanese say, business is war. Your business cannot afford to let down its guard. Corporate security policy must clearly define appropriate and inappropriate behavior.

Security is not one-size-fits-all. Business personnel usually have disparate roles and responsibilities and each position has associated vulnerabilities. There should be a base level of training that everyone in the company is required to complete, and then people must also be trained according to their job profile to adhere to certain procedures that will reduce the chance that they will become part of the problem. People who work with sensitive information or are placed in positions of trust should be given additional specialized training.

Keeping Sensitive Information Safe When people are approached by a stranger offering to help, as seen in the stories in this chapter, they have to fall back on corporate security policy that is tailored as appropriate to the business needs, size, and culture of your company. NOTE Personally, I don't believe any business should allow any exchange of passwords. Its much easier to establish a hard rule that forbids personnel from ever sharing or exchanging confidential passwords. Its safer, too. But each business has to assess its own culture and security concerns in making this choice

Never cooperate with a stranger who asks you to look up information, enter unfamiliar commands into a computer, make changes to software settings or - the most potentially disastrous of all - open an email attachment or download unchecked software. Any software program - even one that appears to do nothing at all - may not be as innocent as it appears to be. There are certain procedures that, no matter how good our training, we tend to grow careless about over time. Then we forget about that training at crunch time, just when we need it. You would think that not giving out your account name and password is something that just about everybody knows (or should know) and hardly needs to be told: it's simple common sense. But in fact, every employee needs to be reminded frequently that giving out the account name and password to their office computer, their home computer, or even the postage machine in the mail room is equivalent to giving out the PIN number for their ATM card.

There is occasionally - very occasionally - a quite valid circumstance when it's necessary, perhaps even important, to give someone else confidential information. For that reason, it's not appropriate to make an absolute rule about "never." Still, your security policies and procedures do need to be very specific about circumstances under which an employee may give out his or her password and - most importantly--who is authorized to ask for the information.

Consider the Source In most organizations, the rule should be that any information that can possibly cause harm to the company or to a. fellow employee may be given only to someone who is known on a face-to-face basis, or whose voice is so familiar that you recognize it without question. In high-security situations, the only requests that should be granted are ones delivered in person or with a strong form of authentication--for example, two separate items such as a shared secret and a time-based token.

Data classification procedures must designate that no information be provided from a part of the organization involved with sensitive work to anyone not personally known or vouched for in some manner.

NOTE Incredibly, even looking up the name and phone number of the caller in the company's employee database and calling him back is not an absolute guarantee social engineers know ways of planting names in a corporate database or redirecting telephone calls.

So how do you handle a legitimate-sounding request for information from another company employee, such as the list of names and email addresses of people in your group? In fact, how do you raise awareness so that an item like this, which is clearly less valuable than, say, a spec sheet for a product under development, is recognized as something for internal use only? One major part of the solution: Designate employees in each department who will handle all requests for information to be sent outside the group. An advanced security- training program must then be provided to make these designated employees aware of the special verification procedures they should follow.

Forget Nobody Anyone can quickly rattle off the identity of organizations within her company that need a high degree of protection against malicious attacks. But we often overlook other places that are less obvious, yet highly vulnerable. In one of these stories, the request for a fax to be sent to a phone number within the company seemed innocent and secure enough, yet the attacker took advantage of this security loophole. The lesson here: Everybody from secretaries and administrative assistants to company executives and high-level managers needs to have special security training so that they can be alert to these types of tricks. And don't forget to guard the front door: Receptionists, too, are often prime targets for social engineers and must also be made aware of the deceptive techniques used by some visitors and callers.

Corporate security should establish a single point of contact as a kind of central clearinghouse for employees who think they may have been the target of a social engineering ruse. Having a single place to report security incidents will provide an effective early-warning system that will make it dear when a coordinated attack is under way, so that any damage can be controlled immediately.

You've seen how social engineers trick people by offering to help.Another favorite approach turns the tables: The social engineer manipulates by pretending he needs the other person to help him. We can all sympathize with people in a tight spot, and the approach proves effective over and over again in allowing a social engineer to reach his goal.

THE OUT-OF TOWNER A story in Chapter 3 showed how an attacker can talk a victim into revealing his employee number. This one uses a different approach for achieving the same result, and then shows how the attacker can make use of that

Keeping Up with the Joneses In Silicon Valley there is a certain global company that shall be nameless. The scattered sales offices and other field installations around the worldare all connected to that company's headquarters over a WAN, a wide area network. The intruder, a smart, feisty guy named Brian Atterby, knew it was almost always easier to break into a network at one of the remote sites where security is practically guaranteed to be more lax than at headquarters.

The intruder phoned the Chicago office and asked to speak with Mr Jones. The receptionist asked if he knew Mr. Jones's first name; he answered, "I had it here, I'm looking for it. How many Joneses do you have?" She said, "Three. Which department would he be in?" He said, "If you read me the names, maybe I'll recognize it." So she did: "Barry, Joseph, and Gordon." "Joe. I'm pretty sure that was it," he said. "And he was in .. which department?" "Business Development." "Fine. Can you connect me, please?" She put the call through. When Jones answered, the attacker said, "Mr. Jones? Hi, this is Tony in Payroll. We just put through your request to have your paycheck deposited directly to your credit union account." "WHAT???!!! You've got to be kidding. I didn't make any request like that. I don't even have an account at a credit union." "Oh, damn, I already put it through." Jones was more than a little upset at the idea that his paycheck might be going to someone else's account, and he was beginning to think the guy on the other end of the phone must be a little slow. Before he could even reply, the attacker said, "I better see what happened. Payroll changes are entered by employee number. What's your employee number?" Jones gave the number. The caller said, "No, you're right, the request wasn't from you, then." They get more stupid every year, Jones thought. "Look, I'll see it's taken care of. I'll put in a correction right now. So don't worry - you'll get your next paycheck okay," the guy said reassuringly.

A Business Trip Not long after, the system administrator in the company's Austin, Texas, sales office received a phone call. "This is Joseph Jones," the caller announced. "I'm in Business Development at corporate. I'll be in to, for the week, at the Driskill Hotel. I'd like to have you set me up with a temporary account so I can access my email without making a long distance call."

"Let me get that name again, and give me your employee number," the sys admin said. The false Jones gave the number and went on, "Do you have any high speed dial-up numbers.

"Hold on, buddy. I gotta verify you in the database." After a bit, he said, "Okay, Joe. Tell me, what's your building number?" The attacker had done his homework and had the answer ready

MITNICK MESSAGE Don't rely on network safeguards and firewalls to protect your information. Look to your most vulnerable spot. You'll usually find that vulnerability lies in your people.

"Okay," the sys admin told him, "you convinced me."

It was as simple as that. The sys admin had verified the name Joseph Jones, the department, and the employee number, and "Joe" had given the right answer to the test question. "Your username's going to be the same as your corporate one, jbjones," the sys admin said, "and I'm giving you an initial password of 'changeme.'"

Analyzing the Con With a couple of phone calls and fifteen minutes of time, the attacker had gained access to the company's wide area network. This was a company that, like many, had what I refer to as candy security, after a description first used by two Bell Labs researchers, Steve Bellovin and Steven Cheswick. They described such security as "a hard crunchy shell with a oft chewy center" - like an M&M candy. The outer shell, the firewall, Bellovin and Cheswick argued, is not sufficient protection, because once an intruder is able to circumvent it, the internal computer systems have soft, chewy security. Most of the time, they are inadequately protected.

This story fits the definition. With a dial-up number and an account, the attacker didn't even have to bother trying to defeat an Internet firewall, and, once inside, he was easily able to compromise most of the systems on the internal network.

Through my sources, I understand this exact ruse was worked on one of the largest computer software manufacturers in the world. You would think the systems administrators in such a company would be trained to detect this type of ruse. But in my experience, nobody is completely safe if a social engineer is clever and persuasive enough.

LINGO CANDY SECURITY A term coined by Bellovin and Cheswick of Bell Labs to describe a security scenario where the outer perimeter, such as firewall, is strong, but the infrastructure behind it is weak. The term refers to M&M candy, which has a hard outer shell and soft center.

LINGO SPEAKEASY SECURITY Security that relies on knowing where desired information is, and using a word or name to gain access to that information or computer system.

SPEAKEASY SECURITY In the old days of speakeasies - those Prohibition-era nightclubs where so-called bathtub gin flowed--a would-be customer gained admission by showing up at the door and knocking. After a few moments, a small flap in the door would swing open and a tough, intimidating face would peer out. If the visitor was in the know, he would speak the name of some frequent patron of the place ("Joe sent me" was often enough), whereupon the bouncer inside would unlatch the door and let him in.

The real trick lay in knowing the location of the speakeasy because the door was unmarked, and the owners didn't exactly hang out neon signs to mark their presence. For the most part, just showing up at the right place was about all it took to get in. The same degree of safekeeping is, unhappily, practiced widely in the corporate world, providing a level of non protection that I call speakeasy security. I Saw It at the Movies Here's an illustration from a favorite movie that many people will remember. In Three Days of the Condor the central character, Turner (played by Robert Redford), works for a small research firm contracted by the CIA. One day he comes back from a lunch run to find that all his co workers have been gunned down. He's left to figure out who has done this and why, all the while knowing that the bad guys, whoever they are, are looking for him.

Late in the story, Turner manages to get the phone number of one the bad guys. But who is this person, and how can Turner pin down his location? He's in luck: The screenwriter, David Rayfiel, has happily given Turner a background that includes training as a telephone lineman with the Army Signal Corps, making him knowledgeable about techniques and practices of the phone company. With the bad guy's phone number in hand, Turner knows exactly what to do. In the screenplay, the scene reads like this:

TURNER RECONNECTS and TAPS OUT ANOTHER NUMBER.

RING! RING! Then:

WOMAN'S VOICE (FILTER) CNA, Mrs. Coleman speaking. TURNER (into test set)

This is Harold Thomas, Mrs. Coleman. Customer Service.

CNA on 202-555-7389, please.

WOMAN'S VOICE (FILTER) One moment, please. (almost at once)

Leonard Atwood, 765 MacKensie Lane, Chevy Chase, Maryland.

Ignoring the fact that the screenwriter mistakenly uses a Washington, D.C., area code for a Maryland address, can you spot what just happened here?

Turner, because of his training as a telephone lineman, knew what number to dial in order to reach a phone company office called CNA, the Customer Name and Address bureau. CNA is set up for the convenience of installers and other authorized phone company personnel. An installer could call CNA, and give them a phone number. The CNA clerk wouldrespond by providing the name of the person the phone belongs to andhis address.

Fooling the Phone Company In the real world, the phone number for CNA is a closely guarded secret. Although the phone companies finally caught on and these days are less generous about handing out information so readily, at the time they operated on a variation of speakeasy security that security professionals call security through obscurity. They presumed that anybody who called CNA and knew the proper lingo ("Customer service. CNA on 555-1234, please for example) was a person authorized to have the information.

LINGO SECURITY THROUGH OBSCURITY An ineffective method of computer security that relies on keeping secret the details of how the system works (protocols, algorithms, and internal systems). Security through obscurity relies on the false assumption that no one outside a trusted group of people will be able to circumvent the system.

MITNICK MESSGAE Security through obscurity does not have any effect in blocking social engineering attacks. Every computer system in the world has at least one human that use it. So, if the attacker is able to manipulate people who use the systems, the obscurity of the system is irrelevant.

There was no need to verify or identify oneself, no need to give an employee number, no need for a password that was changed daily. If you knew the number to call and you sounded authentic, then you must be entitled to the information.

That was not a very solid assumption on the part of the telephone company. Their only effort at security was to change the phone number on l periodic basis, at least once a year. Even so, the current number at any particular moment was very widely known among phone phreaks, who delighted in taking advantage of this convenient source of information and in sharing the how-to-do-it with their fellow phreaks. The CN,' Bureau trick was one of the first things I learned when I was in to the hobby of phone phreaking as a teenager.

Throughout the world of business and government, speakeasy security. is still prevalent. It's likely that about your company's departments, people, and lingo. Sometimes les to than that: Sometimes an internal phone number is all it takes.

THE CARELESS COMPUTER MANAGER Though many employees in organizations are negligent, unconcerned, or unaware of security dangers, you'd expect someone with the title manager in the computer center of a Fortune 500 corporation to be thoroughly knowledgeable about best security practices, right? You would not expect a computer center manager - someone who is part of his company's Information Technology department - to fall victim to a simplistic and obvious social engineering con game. Especially not the social engineer is hardly more than a kid, barely out of his teens. But sometimes your expectations can be wrong.

Tuning In Years ago it was an amusing pastime for many people to keep a radio tuned to the local police or fire department frequencies, listening in on the occasional highly charged conversations about a bank robbery in progress, an office building on fire, or a high-speed chase as the event unfolded. The radio frequencies used by law enforcement agencies and fire departments used to be available in books at the corner bookstore; today they're provided in listings on the Web, and from a book you can buy at Radio Shack frequencies for local, county, state, and, in some cases, even federal agencies.

Of course, it wasn't just the curious who were listening in. Crooks robbing a store in the middle of the night could tune in to hear if a police car was being dispatched to the location. Drug dealers could keep a check on activities of the local Drug Enforcement Agency agents. An arsonist could enhance his sick pleasure by lighting a blaze and then listening to all the radio traffic while firemen struggled to put it out.

Over recent years developments in computer technology have made it possible to encrypt voice messages. As engineers found ways to cram more and more computing power onto a single microchip, they began to build small, encrypted radios for law enforcement that kept the bad guys and the curious from listening in.

Danny the Eavesdropper A scanner enthusiast and skilled hacker we'll call Danny decided to see if he couldn't find a way to get his hands on the super-secret encryption software - the source code - from one of the top manufacturers of secure radio systems. He was hoping a study of the code would enable him to learn how to eavesdrop on law enforcement, and possibly also use the technology so that even the most powerful government agencies would find it difficult to monitor his conversations with his friends.

The Dannys of the shadowy world of hackers belong to a special category that falls somewhere in between the merely-curious but-entirely- benign and the dangerous. Dannys have the knowledge of the expert, combined with the mischievous hacker's desire to break into systems and networks for the intellectual challenge and for the pleasure of gaining insight into how technology works. But their electronic breaking-and- entering stunts are just that--stunts. These folks, these benign hackers, illegally enter sites for the sheer fun and exhilaration of proving they can do it. They don't steal anything, they don't make any money from their exploits; they don't destroy any files, disrupt any network connections, or crash any computer system. The mere fact of their being there, snaring copies of files and searching emails for passwords behind the backs of curity and network administrators, tweaks the noses of the people responsible for keeping out intruders like them. The one-upmanship is a big part of the satisfaction.

In keeping with this profile, our Danny wanted to examine the details of his target company's most closely guarded product just to satisfy his own burning curiosity and to admire whatever clever innovations the manufacturer might have come up with.

The product designs were, needless to say, carefully guarded trade secrets, as precious and protected as just about anything in the company's possession. Danny knew that. And he didn't care a bit. After all, it was just some big, nameless company.