Detecting Malicious Insiders Before Data Breaches Damage Your Business

By Brian Prince  |  Posted 2010-04-06

Detecting Malicious Insiders Before Data Breaches Damage Your Business

As intriguing as the idea of a mysterious cyber-criminal hacking his way into a corporate network sounds, the majority of data breaches are the work of insiders.

An employee copies data to a USB device and leaves it in a cab; a contractor misplaces a CD with customer information-these are common causes of data breaches. But sometimes, it is not an accident, and rather than a master criminal scaling the network perimeter it's a sullen systems administrator causing the havoc.

Dawn Cappelli knows that well. As the technical lead of CERT's insider threat research at Carnegie Mellon's Software Engineering Institute, she has analyzed 450 cases of malicious insiders in search of common threads that businesses can use to develop security strategies. Activity by malicious insiders, she said, can be broken down into three categories: IT sabotage, theft of IP (intellectual property) and fraud.

"If you look at these crimes, you can't detect it with technology alone because a system administrator is going to use his authorized access to do what he does everyday and you can't tell if it's malicious or not unless you know when to look," Cappelli said. "Theft of IP; these people are going to take what they work on everyday. They are going to use their authorized access. Unless you put a strategy together that looks at the people, the process and the technology, it's going to be very hard to detect these things."

In the case of IT sabotage, these incidents are typically committed by someone such as a systems administrator who has privileged access, she said, adding that many of these crimes occur after the person has been terminated. The person will often create a back-door account-an act unlikely to raise red flags since it is not abnormal for administrators to create accounts-so as to be able to enter the network remotely later on. Detecting these types of situations relies on a mix of technology and people, starting with communication between human resources and IT when a disgruntled employee is about to be terminated and warrants closer attention.

"In all of these cases that we have of insider IT sabotage, we don't have a single case where people said, 'Oh, he was such a nice guy I can't believe he ever would have done anything like that,'" Cappelli said. "In all of these cases, it's the person who, they don't get along with people, they cause trouble at work ... and soon as you see somebody who's disgruntled you can't immediately say, 'Uh-oh, you know what, they might attack.' You're looking for this escalation where it gets worse and worse and they don't get over it like most people do."

Communication between human resources and IT can only go so far, of course. Technologies such as logging, activity monitoring and change management also have a key role to play.

Stealing Sensitive Data as They Leave

Typically, "When we see an insider employee involved in a breach, we see that privileges and user rights have not been well-defined, and that the employee has a toxic combination of privileges that allows them access to data that is not required to perform their job," said Thom VanHorn, vice president of global marketing at Application Security. "Implementing best practices and setting up privileges and user rights that provide only the access necessary for the employee's daily job tasks as well as continuously monitoring user rights goes a long way toward preventing insider attacks."

This can certainly be true if someone tries to violate access policies. However, in the breaches she has analyzed, Cappelli said, insiders stealing IP are typically after things they have been working on as they prepare to walk out the door for a new job.

"They are typically scientists, programmers [and] engineers, although about 29 percent of them were salespeople who stole customer information," she said. "But most of them are technical people ... who steal what they work on. So, 'I'm a scientist, I've been working on these chemical formulas ... I'm a programmer, I've been working on this source code,' and that's what they tend to steal. They typically do this using authorized access, during normal working hours, at work."

Most steal the information as they are leaving, within 30 days of their resignation, Cappelli said.

"If you know this person's resigned, look back 30 days and look at what have they been putting on removable media," she said. "Look in your e-mail logs and see what [he or she has] been emailing outside of the network, and make sure that you don't see anything in there that indicates that they may be stealing your IP."

Fraud cases are typically carried out by employees who stay at the company, as opposed to someone who has been fired or is leaving, she said. These people are typically recruited by outsiders to steal or modify information they have access to for pay, and often hold low-level jobs such as data entry, she added.

The good news, if it can be called that, is that most data breaches involving insiders are not malicious at all. In fact, a November survey of 305 IT decision makers by Forrester Research found that roughly 58 percent of the data leak incidents they experienced in the last two years were caused by an employee accident, such as a lost smartphone. Meanwhile, only about 27 percent of the incidents involved an employee, customer service representative or business partner stealing information or abusing access privileges.

"Most insider data breaches are in some way related to a lack of awareness on the part of the employee responsible for the breach," said Mike Spinney, senior privacy analyst at the Ponemon Institute. "They either did something they didn't know was risky behavior, violated a policy they weren't aware of or lacked simple vigilance. Certainly there is always an element of malicious behavior, but for the most part folks are simply doing things without fully comprehending the potential risk."

Though he eschews the term "insider threat" as being overhyped, Forrester Research analyst Andrew Jaquith said companies need to begin their security strategy by identifying the most valuable data, creating a list of data security risks and examining the balance between corporate policy and compliance.

"Our advice, generally, is that companies need to think holistically about the range of risks to their data, whether they are to 'custodial' data like [Social Security numbers] or credit card numbers, or to corporate secrets," Jaquith said. "The approaches that are needed to secure each are usually very different. Technology can help with the accidental stuff-but it's harder with malicious cases."

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