Thinking of connectivity as the gravity center of every modern organization's digital ecosystem isn't a far-fetched perspective. It's deeply ingrained into the very fabric of collaboration, cloud computing, data sharing, remote work, and customer engagement. All these crucial areas take a major hit when a network attack happens. And, the unfortunate reality is that no network is immune.
For the most part, these incursions are predictable, which is both good and bad news. The bad news is that criminals don't need to regularly reinvent the wheel to be successful, as tried and tested methods remain remarkably effective over a long period. The good news is that security teams can learn to anticipate these events and know exactly what to do to stop or prevent them.
Why network security matters
Before zooming in on specific attack methods, it's important to understand what network security is and why it's a top priority. Essentially, this concept encompasses the technologies, processes, and policies used to secure an organization's data and ensure operational continuity.
Cybercriminals are always looking for the easy way in, and the sheer complexity of modern infrastructures gives them exactly that. Networks provide more entry points than security teams can effectively monitor. The increasing use of cloud networks, IoT devices, and remote work policies make network environments more complex than ever, turning them into a high-risk asset for every organization.
That's why a basic understanding of network security risks isn't enough. Security teams need an in-depth understanding of specific threats that are likely to impact the networks they're defending. Most of these are long-standing stratagems, but as they evolve in lockstep with technological advancements, it's worth scrutinizing them through the lens of the present-day IT landscape.
With that in mind, let's look at the most widely encountered network attacks and how companies can defend against them.
1. Distributed Denial of Service (DDoS)
DDoS attacks have surged dramatically over the last few years, and will likely continue to pose a threat considering both how easy they are to execute, and how fast botnets (vast networks of compromised devices) are scaling. During a DDoS attack, the network becomes swamped with malicious bot traffic, making it either significantly slower for normal use, or completely unusable.
Throughout 2024, a wave of botnets were used to launch hundreds of targeted, high-scale DDoS attacks that crippled major organizations across Europe, North America, and Asia. Most of the attacks relied on volumetric floods, which overwhelm their targets with a sheer volume of rogue requests, while others used state exhaustion techniques where too many concurrent connections resulted in server failure.
Defending against DDoS attacks has long depended on traditional measures like firewalls and rate limiting. However, modern botnets have become much better at mimicking legitimate traffic, which directly negates the benefits of these measures. To stay ahead, organizations must turn to artificial intelligence. AI-driven traffic analysis and anomaly detection is a game changer for cybersecurity, especially when it comes to preventing DDoS attacks.
2. Man-in-the-Middle (MitM) attacks
Networks are a way for people to exchange information. To do so, there need to be two parties: a sender and a recipient. But what happens if there is a third, uninvited party sitting between them, silently intercepting or altering their communication? That's exactly what happens in a man-in-the-middle attack.
MitM scenarios exploit weaknesses in network communication channels, allowing cybercriminals to steal sensitive information, including login credentials or financial details. Session cookies, for example, can be easily intercepted with packet sniffing tools when the user connects to an unsecured Wi-Fi network. This type of attack is called session hijacking.
There are several variations of the "in-the-middle" logic, such as Adversary-in-the-Middle (AitM), Browser-in-the-Middle (BitM), and Man-in-the-Browser (MitB). According to Charlie Madere of digital impersonation protection firm Memcyco, such attacks involve the use of phishing websites impersonating companies' websites. The attackers place themselves between the user and the legitimate website, intercepting session data and bypassing multi-factor authentication (MFA) by relaying the authentication process in real time. By impersonating the company's website, attackers trick users into entering their credentials, which are then leveraged by the attacker to take over the session.
"Adversary-in-the-Middle (AitM) attacks use a phishing proxy to intercept and relay communications between the user and the legitimate website, capturing credentials and session tokens," wrote Madere in a blog post. "Browser-in-the-Middle (BitM) involves the attacker controlling the browser environment, allowing them to manipulate or intercept data directly. Man-in-the-Browser (MitB) uses malware to infect the user's browser, modifying transactions and capturing session information without the user noticing."
Defending against MitM attacks can be tricky, as they don't trigger many red flags with users or security tools. This foul play is usually unveiled only after the damage has already been done. For this reason, preventative measures are much more important than reactive ones. This includes encrypting communication within and outside the organization, implementing strict authentication policies, and taking proactive measures to prevent website impersonation attacks. Users must also avoid accessing sensitive information over public networks.
3. Ransomware
While many ransomware attacks start with a phishing email or a stolen credential, the most damaging ones rely on network vulnerabilities to spread laterally and infect large portions of the target environment.
The dark web has a lot to do with the rise in frequency of ransomware attacks, as advanced payloads and tools are readily available. In recent years, the ransomware as a service (RaaS) model has also made its mark, allowing affiliates with little to no technical skill to launch sophisticated ransomware campaigns.
Since software vulnerabilities are a common entry point for ransomware attacks, it's crucial to regularly update your applications and systems to the latest version. Multi-factor authentication (MFA) is also a must to prevent unauthorized access from just a stolen password. Training employees about the dangers of phishing will also pay off, as it prepares them to avoid social engineering attacks, reducing not only the risk of ransomware, but a wide range of other cyberattacks.
4. Kerberoasting (targeting Active Directory)
Active Directory (AD) is Microsoft's authentication and identity management system. It's used in almost all enterprise networks to control access to sensitive resources and services. AD relies on a ticket-based protocol known as Kerberos to securely verify user identities. But as they often do, attackers have found a way to exploit this otherwise robust mechanism.
Once inside a network, a hacker can request Kerberos service tickets for AD accounts. Since no special privileges are required to request these tickets, attackers can extract them from memory and attempt to crack the hashes offline, revealing plaintext credentials. If the breached accounts have special privileges, the hacker can use them to move laterally across the network and further escalate their access.
The onus is on the security teams to make it nearly impossible for someone to decrypt the hashed passwords. How can they do that? By setting long, complex passwords that have a mix of uppercase and lowercase letters, numbers, and special characters. Additionally, they should keep a close eye on Kerberos Ticket Granting Service (TGS) requests. A high number of unusual requests may point to Kerberoasting.
Looking ahead
Network attacks aren't going anywhere; they're only becoming more frequent and advanced. On the upside, security measures are also evolving. One can even argue that attacks are only getting more advanced because cybercriminals constantly try to outpace the level of innovation on the defensive side. So ultimately, the good guys hold the upper hand. Invest in the right strategies and tools, and you will be on your way to building a secure, resilient network.
