An Advanced Persistent Threat (APT) is a long-term cyber attack on a specific network to gain access. Unlike other cyber threats, APTs are sophisticated and carried out by well-funded groups like nation-states. 

But how impactful are APTs exactly? Recent statistics show that 78% of companies that suffered an APT attack have experienced downtime as a result of it, according to Purplesec. Also, in 2021, the market for advanced persistent threats was $5.9 billion, and it’s projected to expand to $30.9 billion by 2030, growing at an annual rate of 20.5%, as stated by AlliedMarketResearch.

This article explains what APTs are, their stages, tactics, and how to stop them.

Quick Facts

• Advanced Persistent Threats (APTs) are sophisticated, long-term cyber attacks by well-funded groups like nation-states or organized crime for cyber espionage, financial gain, or political objectives.

• APTs go through three stages – gaining access via initial infiltration through spear-phishing or exploiting known vulnerabilities, expansion of access using advanced tools and malware, and data exfiltration through encrypted channels while evading detection.

• Best practices to defend against APTs are Web Application Firewalls (WAFs), penetration testing, whitelisting, access control, two-factor authentication, and real-time monitoring tools like Endpoint Detection and Response (EDR) and Extended Detection and Response (XDR) to detect and respond to threats fast.

What is an Advanced Persistent Threat (APT)?

An Advanced Persistent Threat (APT) is a highly advanced and long-term cyber attack on high-value networks. Unlike other cyber attacks APTs:

• Infiltrate and maintain unauthorized access to a network for months or even years.

• Plan and execute the attack meticulously.

• They are carried out by well-funded and experienced actors like nation-states or organized crime.

• Have cyber espionage, financial gain, hacktivism, or destruction as their primary objectives.

The motivations behind APTs are political or economic, attackers want to get classified data, intellectual property, or sensitive information from their targets. These targets are government agencies, financial institutions, telecommunications utilities, and high-tech companies.

Kaspersky states that "APTs are usually leveled at high-value targets, such as nation-states and large corporations."

For example, APT actors might want to steal intellectual property from a tech company or classified information from a government agency to get a competitive advantage or disrupt operations.

APTs are different from other cyber threats because of their persistence. The attackers are not satisfied with a quick infiltration, they want to establish a long-term presence in the target network. 

This persistence allows them to gather valuable data and adapt their tactics to evade detection. As a result, APTs are a big and ongoing challenge for security professionals who have to constantly evolve their defenses to stop these advanced threats.

MarketsandMarkets.com predicts that the APT Protection industry will experience a compound annual growth rate of 19.5%, reaching a value of $12.6 billion by the end of 2025.

APT Attack Stages

APTs are not one-time events but a series of steps. These attacks go through three stages – initial infiltration, expansion of access, and data exfiltration. Each stage builds upon the previous one, allowing the attackers to get deeper into the target network and achieve their objectives.

Understanding these stages is key to creating effective APT security and responding to any signs of an attack. Implementing robust APT security measures, including real-time monitoring and multi-layered defenses, is essential to respond effectively to any signs of an attack.

Initial Infiltration

The initial infiltration stage is where the attackers gain access to the target network, often through spear-phishing emails, social engineering, or exploiting known vulnerabilities in the target’s systems. As mentioned by Cisco: 

"APTs often use social engineering tactics or exploit software vulnerabilities."

For example, the Sykipot attacks targeted U.S. and U.K. defense contractors using spear-phishing to exploit vulnerabilities in Adobe Reader and Acrobat. The Stuxnet Worm infected Iranian industrial infrastructures by infecting Windows machines via USBs to interfere with Siemens Step 7 software on PLCs.

Web Application Firewalls (WAFs) are the first line of defense against these initial infiltration tactics. WAFs can isolate application-layer attacks like Remote File Inclusion (RFI) and SQL injection which are used during this stage. 

Enterprises get infiltrated through their web assets, network resources, and authorized human users. So it’s crucial to have robust defenses that can detect and stop these initial attacks.

Expansion of Access

Once initial access is gained, the attackers move laterally across the network, compromise more systems, and gather credentials. To get access to more systems this stage involves:

• Installing backdoors for remote command-and-control communication

• Deploying trojans and malware to maintain access

• Using stolen credentials

• Privilege escalation techniques like Pass-the-Hash can be used to get higher-level access to the network.

During the expansion phase, the attackers set up command and control servers to manage their operations remotely. They move up the organization’s hierarchy, targeting staff with access to sensitive data, so they have more control over the network. 

This widespread presence and use of advanced tools make it hard for defenders to detect and remove all the attacker’s footprints.

Data Exfiltration

In the last stage, data exfiltration, the attackers steal sensitive data from the compromised network. They use tunneling techniques or encrypted channels to exfiltrate the stolen data out of the target environment. 

Often the stolen data is stored in a secure location within the network before exfiltration. To distract security personnel the attackers might use white noise tactics like DDoS attacks during this stage.

The goal is to steal data without alerting the target organization. By creating files of unusual size or format the attackers can exfiltrate data off the server silently. This is the final stage of the APT attack where the attackers achieve their primary objective of data theft.

Characteristics of Advanced Persistent Threats

APT attacks are:

• Well planned

• Highly customized

• Targeted at a specific organization

• Evade existing security controls

• Operate undetected for a long time

This level of sophistication requires a lot of time, resources, and expertise in database operations.

One of the key characteristics of APTs is their persistence. These attacks can stay active in the network for months or even years, gathering sensitive information and adapting to evade detection. 

This persistence allows the attackers to have a long-term presence in the target network making it hard for security teams to completely remove the threat.

The level of sophistication and investment in APT attacks suggests that the attackers are well-funded and have a team of experienced cybercriminals at their disposal. 

They use custom malware, sophisticated social engineering, and advanced tools to breach the network and exploit specific vulnerabilities identified through extensive research and reconnaissance. APTs are one of the most challenging and dangerous types of cyber threats.

APT Groups Tactics

APT groups use various tactics to get into and maintain access to the target network. One of the most common tactics is spear phishing where the attackers send highly personalized emails to the target to trick them into clicking on the malicious links or opening infected attachments. These emails are often made to look legitimate so hard to detect and avoid.

Another tactic is zero-day exploits which target unpatched operating system vulnerabilities. These are more dangerous because they can bypass traditional security tools like antivirus and firewalls.

Sophisticated actors like ransomware gangs have become good at exploiting vulnerabilities fast, sometimes within a day of disclosure. Patching network software is key to mitigating the risk of these threats.

APT groups also use rootkits to provide hidden backdoor access to compromised systems. These tools allow the attackers to have a persistent presence in the network while evading detection. 

Notable APT Attacks

Several APT attacks have made headlines over the years. One of them is Titan Rain, a series of cyber attacks that started in 2003 and targeted various US-based organizations. Believed to be from China, these attacks were focused on stealing sensitive military data from organizations like NASA and the FBI.

Another well-known APT group is Fancy Bear also known as APT28 which is linked to Russian military intelligence. Active since at least 2007, Fancy Bear has been involved in cyber espionage operations against political organizations, military institutions, and media outlets. Their activities have had significant geopolitical implications showing the impact of APTs on global affairs.

The Lazarus group from North Korea has been known to attack cryptocurrency exchanges and financial institutions. GhostNet cyber espionage campaign detected in 2009 compromised over 100 countries, targeting embassies and government ministries. These examples show the global reach and impact of APTs.

Detecting Advanced Persistent Threats

Detecting APTs requires monitoring of network activities and user actions. One of the warning signs is anomalies in outbound data transfer which could mean data exfiltration by an APT. Monitor both ingress and egress traffic to detect abnormal activities that may indicate APT presence.

Atypical user behavior like logging in at unusual hours or accessing unexpected resources may also indicate APT presence. Internal traffic monitoring tools can help identify these unusual logins and data transfers. Automated contextual enrichment in detection tools can also help security teams quickly understand and respond to threats by aggregating data from multiple sources.

Advanced detection tools and techniques like real-time network traffic analysis, anomaly detection, and user behavior analytics are key to detecting APTs. These tools can help security teams to detect and act on malicious activity early.

According to ScienceDirect, a protection system based on machine learning called MLAPT has undergone experimental evaluations, and the results show that it can predict advanced persistent threats (APTs) in their early stages with an accuracy of 84.8%.

APT Security Best Practices

Having effective security measures in place is key to preventing APT attacks. Penetration testing is one proactive measure that helps to identify and fix vulnerabilities in the network and systems before attackers can exploit them. 

By simulating an attack, organizations can know their security weaknesses and take steps to harden their defenses.

Whitelisting is another best practice that controls the domains and applications that can be accessed, reducing the attack surface. However, it is important to enforce strict update policies to ensure users are always running the latest version of the listed applications. 

Access control is also key to preventing unauthorized access to sensitive systems and data, to limit the attacker’s ability to view or modify critical information.

Two-factor authentication (2FA) can secure critical network access points, adding an extra layer of protection against unauthorized access. By having these security measures in place organizations can reduce the risk of APT attack and protect their assets.

Developing new APT security measures, including multi-faceted security strategies and centralized real-time monitoring, is another important step.

Web Application Firewalls in APT Defense

Web Application Firewalls (WAFs) play a key role in APT defense as they filter traffic to web application servers. WAFs protect against application layer attacks like Remote File Inclusion (RFI) and SQL injection which are used during the initial infiltration stage of APTs. 

By inspecting incoming traffic for malicious activity WAFs can block potential threats before they reach the vulnerable web application servers.

WAFs offer:

• A custom rules engine for access control and enforcement of specific security policies.

• Customization to fit specific needs, to have higher protection against APTs.

• Installation at the network edge to create a strong barrier against application layer attacks.

Speed in APT Response

Speed is key in responding to APTs since threat actors are deploying faster attack methods than ever. Rapid detection and response are key to minimizing the damage of APTs. 

The global median dwell time of APTs is decreasing, meaning that attacks are getting faster, so organizations need to respond fast to mitigate damage.

EDR and XDR tools provide real-time visibility into device activities to detect suspicious or malicious behavior. Autonomous tools like AI-powered EDR and XDR are being used to manage the rapid detection and response to APTs. MDR services offer 24/7 monitoring and threat hunting to add an extra layer of security to detect and respond to threats.

FAQs

What is the difference between Advanced Persistent Threats (APTs) and regular cyber-attacks?

The main difference between Advanced Persistent Threats (APTs) and regular cyber-attacks is the long-term, sophisticated, and targeted nature of APTs to infiltrate and maintain unauthorized access to high-value networks for extended periods.

How do attackers get initial access in an APT attack?

Attackers gain access in an APT attack through spear-phishing emails, social engineering, or exploiting known vulnerabilities in the target’s systems.

What are the common tactics used by APT groups to maintain access to the network?

Common tactics used by APT groups to maintain access in the network are lateral movement, privilege escalation, and deploying backdoors and rootkits. This allows them to stay persistent in the network.

How can organizations detect APT in their network?

Organizations can detect APTs by monitoring outbound traffic for anomalies, and unusual user behavior and using advanced detection tools that provide real-time visibility and threat context. This can help them to detect and respond to APTs in their network.

How to defend against APTs?

Penetration testing, whitelisting, access control, 2FA, and WAF are used to defend against these attacks. Also, implementing comprehensive APT security measures, including multi-faceted security strategies and centralized real-time monitoring, is essential to protect against these sophisticated threats.

Summary

Advanced Persistent Threats (APTs) are some of the toughest challenges in cybersecurity. These sophisticated long-term attacks require deep understanding and robust defense strategies to mitigate the impact. From initial infiltration through social engineering and vulnerability exploitation to lateral movement and privilege escalation to data exfiltration, APTs are well-planned and executed. 

Detection relies on monitoring network anomalies and unusual user behavior, while robust security measures like penetration testing, whitelisting, access control, and 2FA are key to defending against these persistent threats. WAFs also play a big role in defending against application layer attacks and rapid response tools like EDR, XDR, and MDR services are critical in minimizing damage. 

Staying vigilant and proactive is the key to defending against the ever-changing APT landscape.