This chapter is from the book
This chapter is from the book
This chapter is from the book
Common Threat Categories
Many threats can affect an organization. In this section, we discuss various types of threats that could potentially and probably have affected an organization you have engaged with in the past. These include malware and advanced persistent threat (APT). Let’s dig in!
Malware
NIST SP 800-83 Rev. 1 states that “Malware, also known as malicious code, refers to a program that is covertly inserted into another program with the intent to destroy data, run destructive or intrusive programs, or otherwise compromise the confidentiality, integrity, or availability of the victim’s data, applications, or operating system.” Attackers use malware to gain unauthorized access to system files and other data. Typically, if your system is infected with malware, you will see an increase in system crashes, slow response times, and files not opening. There are a variety of different types of malware, including viruses, worms, Trojans, and ransomware.
Malware is designed specifically to disrupt, damage, or gain unauthorized access to a computer system. Malware can be downloaded on your system via email, from URLs you click, or from additional websites you visit. In each case, malware can damage your entire system, causing you to work overtime to fix the issue.
Viruses
Viruses are some of the most notorious malware variants out there. A virus is a program that runs on computer systems without the users’ knowledge. If a user or system executes a compromised file, the virus can spread copies of itself throughout the network. Viruses utilize system resources to replicate and spread quickly through a network, which can impact performance and slow systems down.
One of the most dangerous viruses of the Internet era was the Melissa virus, which provided free credentials to adult websites in 1999 through email and forums. This virus was spread via Microsoft macros through Word email attachments. When a user opened an email with a Word attachment, the virus would send copies of itself to the first 50 contacts in their address book, causing widespread disruption affecting more than 300 organizations that year. Melissa was able to exploit the trust associated with opening email attachments proliferating and overwhelming email servers. Microsoft permanently blocked Internet access to Office macros in 2022.
Worms
Worms are standalone, self-replicating malware that causes significant damage to an organization’s environment. Worms are typically spread through the Internet or a local area network (LAN). They will use the resources on the first compromised system(s) to start reconnaissance on the rest of the network.
Worms can be spread in a variety of ways:
Phishing emails that are designed to trick the recipient into clicking a link can spread worms. Typically, phishing, as a form of social engineering, plays on human behavior. A subtype is spear phishing, which is a more targeted phishing campaign that usually targets executives or other employees higher in the organizational hierarchy. Phishing emails are regularly used to manipulate people into divulging information.
Network access via shared network drives allows worms to spread through those areas quickly.
Worms may use security holes and misconfigurations to spread throughout your organization.
External devices such as USB drives and CDs can contain a worm that then spreads to other systems to cause havoc. To mitigate this risk, organizations employ data loss prevention (DLP) tools to monitor device use.
The Stuxnet worm, first detected in 2010, spread via USB drives and was mostly used for cyber warfare. This worm targeted critical industrial control system (ICS) infrastructure used to control nuclear power plants. This worm was the first of its kind worldwide, thus changing how we look at security for systems that were not built with security in mind.
Trojans
In Greek mythology, the Greeks defeated the city of Troy during the Trojan War by hiding soldiers in a giant wooden horse left outside the city gates, waiting for the Trojans to bring the horse inside to celebrate their apparent victory after the Greeks had pretended to retreat. The Greek soldiers then emerged from the horse’s belly and sacked the city. Aptly named for that horse, Trojans operate in the same manner. Trojans are malicious programs or software disguised as harmless, useful tools to trick users into downloading them, after which they exfiltrate data from the system on which they are installed. Additionally, Trojans are stealthy, can be executed without permission or the user’s knowledge, and serve a specific purpose such as data theft, remote control, facilitating other attacks, or persistence in the system.
The Trojan named Zeus, first detected in 2007, was designed to steal personal and financial data from compromised systems. What was unique at the time was that the hackers used Zeus to rope other systems into a botnet to steal money from major corporations, causing over $70 million in damages.
Ransomware
Ransomware has been a major threat in the tech space in the past few years, affecting government agencies, healthcare systems, and school systems and causing massive financial losses to organizations. Ransomware is malicious software that encrypts your data or systems to block access in exchange for some form of payment to regain access and decrypt that information, as illustrated in Figure 3-1. Threat actors use ransomware to access high-value data such as financial and intellectual property.
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Figure 3.1 Ransomware (Image Credit: Nicescene/Shutterstock)
Ransomware can be delivered through various means, such as phishing emails or software vulnerabilities. It’s important to note that ransomware typically has three main factors: encryption capabilities, a time limit to pay the ransom, and the ability to spread across networks.
Let’s discuss two notable ransomware attacks that had very different impacts on organizations. WannaCry was discovered in 2010 and affected more than 200,000 systems across the globe by spreading through phishing emails and network scanning. WannaCry was able to spread quickly due to vulnerabilities in older versions of Microsoft software. The motive behind WannaCry was financial gain. Organizations impacted by WannaCry had to pay the attackers in Bitcoin to have their data decrypted.
While WannaCry was for financial gain, the incident at Colonial Pipeline in 2021 caused a disruption of operations up and down the East Coast. This pipeline supplies 45% of the East Coast with fuel. This attack was attributed to the threat group DarkSide, which demanded that Colonial Pipeline Company pay 75 Bitcoin (worth approximately $5 million at the time) to access its systems again. The company paid the ransom and was able to resume operations. The Colonial Pipeline incident caused gas shortages for almost a week, leading to panic buying, price spikes in gas, and concerns for national security because the pipeline is considered critical infrastructure.
Advanced Persistent Threats
An advanced persistent threat (APT) is a highly sophisticated and targeted attack conducted by skilled threat actors, typically state-sponsored groups, looking to gain access to sensitive data or cause a disruption in operations. These threat actors utilize the malware techniques previously described to gain access to systems and wait. APTs have multiple stages of execution and can go undetected for long periods. Data exfiltration, intelligence gathering, or other malicious activities can occur during this time. Initial access for these actors typically is gained either through phishing or zero-day exploits. Network segmentation and a defense-in-depth strategy are great ways to protect against APT attacks. Additional detection and protection measures are discussed throughout this chapter.