Insider threats are a huge and growing problem. The Verizon 2019 Insider Threat Report collected data of about 53,308 security incidents and reports that insider privilege misuse represents 20 percent of all cybersecurity incidents and nearly 15 percent of all data breaches.

Why do insiders go bad? According to the report, the motivation of over 50 percent of insiders is financial, under 20 percent are conducting espionage, while only 8 percent act out of a grudge towards their employer. Insider threats are extremely common in the healthcare industry (over 30 percent of organizations reporting incidents) and government institutions (over 20 percent).

Read on to get a complete picture of the insider threat problem: what are insider threats, how they operate, and how attackers compromise insiders to carry out attacks. We’ll also cover organizational and behavioral signals that can help you detect insider threats, and four key strategies to protect against insider threats.

In this article you will learn:

What is an insider threat?

An insider threat is a malicious activity against an organization that comes from people within the organization. The usual suspects are employees or contractors with access to an organization’s network, applications or databases. The term is most commonly used to describe illicit or damaging online actions.

There are several types of insider threat:

  • Malicious Insider—an employee or contractor who knowingly looks to steal information or disrupt operations. This may be an opportunist looking for ways to steal information that they can sell or which can help them in their career, or a disgruntled employee looking for ways to hurt an organization, punish or embarrass their employer.
  • Negligent Insider—an employee who does not follow proper IT procedures. For example, someone who leaves their computer without logging out, or an administrator who did not change a default password or failed to apply a security patch.
  • Compromised Insider—a common example is an employee whose computer has been infected with malware. This typically happens via phishing scams or by clicking on links that cause malware downloads. Compromised insider machines can be used as a “home base” for cybercriminals, from which they can scan file shares, escalate privileges, infect other systems, and more.

Insider threats and privilege escalation

Typically, insiders carry out their plans via abuse of access rights. The attacker may try what is known as privilege escalation, which is taking advantage of system or application flaws to gain access to resources they do not have permission to access.

Insider Threat Privilege Escalation
Figure 1 – Using privilege escalation, an attacker can move horizontally, gaining access to other user or service accounts, or vertically, gaining greater access via power users or administrators

In some cases, abuse of access rights takes the form of someone with privileged access abusing their power. In 2008, a system administrator working for the San Francisco city government blocked access to the city’s network and refused to surrender the admin passwords. The worker was disgruntled, and his job was in jeopardy, it was revealed.

Insider threat statistics: how big is the problem?

Insider threats are a growing problem, as evidenced by recent survey data:

  • 90% of companies feel that they are vulnerable to insider attacks
  • 53% of organizations have experienced an insider attack themselves
  • 86 percent of companies are working on a program to prevent insider attacks
  • 66 percent of organizations believe malicious or accidental insider threats are the most likely cause of security breaches; only 34 percent feel the most likely cause is an external attack

Insider threat motivations

While most often associated with stealing information, any action that could negatively impact an organization falls into the insider threat category. This includes sabotage, fraud, and espionage.

Insider Type Motivations Risks
Malicious Making money or avenging a slight Theft of core company intellectual property. Disruption of operations. Damage to company reputation.
Negligent Ignorance or carelessness Theft of core company intellectual property. Disruption of operations. Damage to company reputation.
Compromised Oblivious to the risk they pose Access to sensitive company systems or assets. Theft of core company intellectual property.

Table 1 – Insider threats are caused by malicious, negligent, and compromised individuals whose motivations are quite different.

How are employees compromised

There are several means by which an employee can become a compromised insider:

Phishing – a cybercrime in which a target individual is contacted via email or text message by someone posing as a legitimate institution in order to lure the individual into providing sensitive data, such as personally identifiable information (PII), banking and credit card details, and passwords. Some phishing schemes may also try to entice a target to click on a link that triggers a malware download.

Malware infection – a cybercrime when a machine is infected with malicious software – malware – infiltrates your computer. The goal of the malware in the case of a compromised insider is to steal sensitive information or user credentials. A Malware infection can be initiated by clicking on a link, downloading a file, or plugging in an infected MP3, among other ways.

Credential theft – a cybercrime aimed at stealing a the username and password – the credentials – of a targeted individual. Credential theft can be done in a variety of ways. Phishing and malware infection, mentioned above, are common. Some criminals may engage in social engineering, which is the use of deception to manipulate individuals into divulging their credentials. A bogus call from the IT helpdesk, where the user is asked by the attacker to confirm their username and password, is a common technique.

Pass-the-hash – a more advanced form of credential theft where the hashed – encrypted or digested – authentication credential is intercepted from one computer and used to gain access to other computers on the network. A pass-the-hash attack is very similar in concept to a password theft attack, but it relies on stealing and reusing password hash values rather than the actual plain text password.

How to detect and investigate malicious insider threats with Exabeam

Detecting insider threats: tell-tale signs

Organizations can spot or predict insider threats by observing user behavior in the workplace and online. Being proactive may allow organizations to catch potentially malicious insiders before they exfiltrate proprietary information or disrupt operations.

The following table shows behaviors and organizational traits that are tell-tale signs of an insider threat.

Employee/Contractor Behavioral Trait Organizational Event
Interest outside scope of their duties Layoff
Working unusual hours without authorization Annual merit cycle – individuals not promoted
Excessive negative commentary about organization Annual merit cycle – individuals not given raises
Drug or alcohol abuse
Financial difficulties
Gambling debt
Change in mental state

Table 2 – Employee or contractor behavioral traits, and organizational events, that should be heeded to reduce the risk of insider threats.

IT security should also observe online behavior traits. The following table lists some of the most common suspicious behaviors.

Behavior Malicious Insider Compromised Insider
Badging into work at unusual times
Logging in at unusual times
Logging in from unusual location
Accessing systems/applications for the first time
Copying large amounts of information

Table 3 – Behaviors that suggest malicious or compromised insiders.

Four ways to prepare against insider threats

There are many things an organization can do to combat insider threats. Here are the four main areas to focus on.

1. Train Your Employees

Conduct regular anti-phishing training. The most effective technique is for the organization to send phishing emails to its users and focus training on those users who do not recognize the email as a phishing attempt. This will help reduce the number of employees and contractors who may become compromised insiders.

Organizations should also train employees to spot risky behavior among their peers and report it to HR or IT security. An anonymous tip about a disgruntled employee may head off a malicious insider threat.

2. Coordinate IT Security and HR

There is no shortage of stories about IT security teams that were blindsided by layoffs. Coordination between the CISO and the head of HR can help prepare IT security. Simply putting affected employees on a watchlist and monitoring their behavior can thwart many threats. Likewise, HR may advise IT security about certain employees that were passed over for a promotion or not given a raise.

3. Build a Threat Hunting Team

Many companies have dedicated threat hunting teams. Rather than reacting to incidents after they are discovered, threat hunting takes a proactive approach. Dedicated individuals on the IT security team look for telltale signs, such as those listed above, to head off theft or disruption before it occurs.

4. Employ User Behavioral Analytics

User Behavior Analytics (UBA), also known as User and Entity Behavior Analytics (UEBA), is the tracking, collecting, and analyzing of user and machine data. Using various analytical techniques, UBA determines normal from anomalous behaviors. This is typically done by collecting data over a period of time to understand what normal user behavior looks like, then flagging behavior that does not fit that pattern. UBA can often spot unusual online behaviors – credential abuse, unusual access patterns, large data uploads – that are telltale signs of insider threats. More importantly, UBA can often spot these unusual behaviors among compromised insiders long before criminals have gained access to critical systems.

Insider threats are not going away. By better understanding the different types of insiders and the behaviors they exhibit, organizations can be better prepared to fight these threats. A combination of training, organizational alignment, and technology is the right approach.

Further reading

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