Advanced Persistent Threats (APTs) and Proxy Defense

by Dan Goodin
27 Jan 2024

"Proxy & VPN Virtuoso. With a decade in the trenches of online privacy, Dan is your go-to guru for all things proxy and VPN. His sharp insights and candid reviews cut through the digital fog, guiding you to secure, anonymous browsing."

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Learn everything about APTs and ways of protecting yourself against those

So, you’ve most likely bumped into the term “Advanced Persistent Threats” or APTs. Sounds ominous, right? Well, for anyone steering a business, it’s a wake-up call, indeed. These cyber threats linger and lurk, subtly undermining your digital security. The real question you should be asking isn’t “Should I be worried?” but rather “What can I do about it?” This guide is here to help. In it, I will explain all there’s to know about APTs, their impact on businesses, and, most importantly, the proven protection strategies.

What Are Advanced Persistent Threats?

Advanced Persistent Threats, or APTs, are a breed of cyber threats that operate differently from the typical hit-and-run cyberattacks most are familiar with. Unlike regular cyberattacks that aim for immediate damage or theft, APTs play the long game. They quietly infiltrate a system and may remain undetected for months or even years.

These attacks usually have a specific target — it could be intellectual property, financial data, or strategic business plans. The attackers spend time understanding their target, identifying vulnerabilities, and crafting a bespoke approach. Here are a few features that set these attacks aside from the rest:

  • they use sophisticated hacking techniques (e.g., zero-day vulnerabilities, custom malware, etc.);
  • they don’t rely on a single method but employ a variety of tactics like phishing, exploitation of software vulnerabilities, and social engineering;
  • once inside, the attackers continuously monitor network activities and communications, extracting valuable data over time so it’s not a one-time theft;
  • APTs are usually backed by well-resourced groups, which could be state-sponsored or large criminal organizations.

For businesses, the impact of these attacks can be, indeed, devastating from loss of sensitive data to significant financial and reputational damage. This impact is, among all else, a long-lasting one.

Check my recent article about cyberthreats businesses are facing in 2024.

Who Are the Main Targets of APTs?

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APTs may target businesses of all levels, not only big ones

When it comes to APTs, there’s a common misconception that only the “big fish” — multinational corporations, governments, and critical infrastructure sectors — are targeted. In reality, it is more nuanced and concerning.

High-Value Targets

Certainly, APTs often zero in on high-profile targets where the stakes are high. Government agencies might be attacked for state secrets, large corporations for their intellectual property, and critical infrastructures like power grids or financial systems for their potential to disrupt national security or economies.

Supply Chain Vulnerabilities

Smaller businesses, particularly those in the supply chain of larger organizations, are increasingly targeted, too. Attackers exploit these smaller entities as they often have less robust security measures. It’s a smart strategic move — compromise the smaller partner to infiltrate the larger target.

Sector-Specific Targeting

Certain industries are more likely to be targeted than others due to the nature of their data or operations. Healthcare, for instance, holds vast amounts of personal data which makes it a lucrative target for APT groups.

The Geopolitical Factor

Sometimes, the choice of target is driven by geopolitical motives. State-sponsored APT groups might target organizations in countries that are geopolitical rivals.

All in all, the scope of APT targets is continuously evolving. Businesses tend to digitize their operations and the opportunities for these attacks widen. No industry or size of business is completely safe from these threats today.

5 Core Issues with Managing APTs

APTs are more like calculated operations than random attacks. Here are a few factors that make these threats so tough to defend against.

Expert Disguise and Stealth

The strength of APTs is in their stealth. They often use encryption and mimic legitimate traffic to blend in. This is so effective that standard security tools, which look for obvious signs of intrusion, often miss them.

Long-term Infiltration

Once they breach a network, the threats embed themselves deeply and go to great lengths to maintain their presence. They constantly change tactics which is why they are so hard to root out. They gather valuable data over time, which could range from trade secrets to personal information.

Sophisticated Techniques

 The operatives behind APTs are usually professionals with a deep arsenal. They use advanced methods like custom malware and exploiting zero-day vulnerabilities. This means they can bypass even the most robust security defenses.

Highly Targeted Attacks

These threats are not random but are carefully planned and executed against specific targets. Attackers spend time researching their victim’s weaknesses and tailoring their approach. That is, they can create bespoke attacks that are much harder to predict or defend against.

Adaptive and Evolving

As cybersecurity measures evolve, so do APT strategies. This constant evolution makes it challenging for organizations to keep up. It’s like playing a game of chess with an opponent who’s always thinking several moves ahead.

3 Ways Proxies Help With Protection Against APTs

One way to add an extra layer of security when dealing with APTs is with the help of proxies. Here’s how they can assist.

They Conceal Your Digital Presence

Proxies are VERY good at shrouding your digital identity. They mask your network’s true IP address so when you have a proxy in place, attackers targeting your network encounter the proxy’s IP instead of your actual one. This complicates their task of profiling your network for vulnerabilities.

They Gatekeep and Manage Traffic

Proxies act as gatekeepers meaning that they control, filter, and manage incoming and outgoing traffic. They set stringent rules on what types of traffic are allowed and prevent suspicious activities from reaching your network.

They Monitor and Detect Anomaly

You can configure proxies to perform deep inspections of the data passing through them. This is vital in identifying and responding to APT-related anomalies. For instance, if a proxy detects unusual outbound traffic (a potential sign of data exfiltration), it can trigger alerts or even block the traffic.

How to Implement Proxies Against APTs: A Full Guide

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Set up the proxy defense against APTs in 5 steps

#1 Conduct a Network Vulnerability Assessment

To begin with, thoroughly assess your network’s vulnerabilities. Use network scanning tools to identify potential weak points. Focus on aspects such as

  • outdated software
  • unpatched systems
  • open ports that may be unnecessary.

Regular assessments are crucial because vulnerabilities can emerge constantly. It’s also a good idea to occasionally have a third-party security audit for an objective analysis.

#2 Choose the Right Proxy Solution

Evaluate whether forward, reverse, or transparent proxies best suit your needs. For example, a reverse proxy is ideal for protecting internal networks from external threats.

When selecting a vendor, look for a proven track record in cybersecurity, and compare features, customer reviews, and support services. Ensure the solution is customizable to your requirements, like traffic volume handling and integration with existing security systems.

Find the best proxy providers that offer guaranteed quality.

#3 Deploy and Configure Proxies

Follow the vendor’s guidelines for installation, whether it involves setting up physical hardware or configuring cloud-based software. Define stringent rules for traffic management, such as blocking traffic from certain regions or filtering specific web content.

It’s also important to double-check that your proxy integrates seamlessly with your existing security infrastructure, such as firewalls and intrusion detection systems. This is vital for creating a unified and robust defense against APTs.

#4 Update and Maintain

Keep your proxy defenses strong by regularly updating the software. These updates help to patch vulnerabilities and enhance functionality. Monitor the proxy’s performance for signs of unusual activity, which could indicate a security breach. Regularly auditing the logs will also help you understand traffic patterns and identify potential anomalies.

#5 Train the Team

A well-informed team is an asset. Develop relevant training programs to educate staff on cybersecurity best practices and the role of proxies in your security setup. Keep your team updated on the latest threats and teach them how to recognize signs of breaches. Conduct simulated APT attacks to test both your team’s response and the effectiveness of your proxy setup.

Beyond Proxies: 3 More Tools That May Help

While proxies form an integral part of your defense strategy against APTs, a holistic approach is always the strongest. Here are four additional tools that work in tandem with proxies to fortify your cybersecurity.


Firewalls enforce security policies as they block unauthorized access attempts and potentially harmful data packets. If you use them, make sure to regularly update firewall rules to adapt to new threats and changing network configurations. Your firewall settings must be also fine-tuned to work seamlessly with your proxies.

Tip: Periodically review your firewall logs. Unusual traffic patterns or frequent blockades might indicate attempted APT activities.

Antivirus Software

Effective antivirus software is a must-have. It scans your systems for known malware signatures and suspicious behaviors. Just like firewalls, your antivirus must always be updated to the latest version. It’s best to integrate antivirus software with other security measures like proxies.

Tip: Schedule regular full-system scans outside of peak hours to minimize disruption while maintaining rigorous malware checks.

Intrusion Detection Systems (IDS)

IDS tools continuously monitor your network for unusual activities. They analyze traffic patterns and alert you to any anomalies, such as unexpected data flows or unauthorized attempts to access network resources. Pairing an IDS with your proxy setup enhances your ability to detect and respond to subtle signs of APT activities that might otherwise go unnoticed.

Tip: Prioritize setting up your IDS alerts to concentrate on high-risk areas of your network. Frequent alerts for minor issues can lead to “alert fatigue,” where important warnings are inadvertently ignored.

Final Thoughts

In the face-off against APTs, proxies are, indeed, a powerful ally. But remember, they’re part of a larger strategy. You now know how to combine proxies with other security instruments to create a multi-layered defense. Implementing these solutions will take time, but it’s the most reliable way to keep your digital assets safe in 2024.


Can small businesses also be targets for APTs?

Yes, small businesses can be targets for these threats, especially those in the supply chain of larger organizations. APTs often exploit smaller entities as entry points to larger networks.

How to identify an APT attack?

Look for signs like unusual network usage, prevalence of backdoor Trojans, unexplained data stockpiling, and abnormal data movements within the network.

Are there specific industries more vulnerable to APTs?

Certain industries like healthcare and finance, which hold vast amounts of personal data, are more likely to be targeted due to the lucrative nature of the information they hold.

How do Advanced Persistent Threats usually infiltrate a network?

They commonly use methods like phishing, exploitation of software vulnerabilities, and advanced malware to infiltrate a network.

What makes APTs different from other cyber threats?

These threats are characterized by their long-term presence, sophisticated tactics, targeted nature, and their ability to adapt and evolve with cybersecurity measures.

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