Advanced Persistent Threat (APT) Definition

KZero Staff
Jul 27, 2023

What is an Advanced Persistent Threat?

Cyberattacks come with varying goals and levels of sophistication. An Advanced Persistent Threat (APT) is an attack that poses an ongoing threat to an organization. Often, these are performed by sophisticated threat actors with significant resources, often backed by nation-states or organized crime.

What is an APT?

Some cyberattacks are opportunistic. For example, if an attacker identifies a vulnerability in an organization’s systems, they might exploit that vulnerability and use it to steal data or plant malware. Ideally, the attacker will get a relatively quick payout from the attack and may not put extensive effort into hiding their presence on the system.

Other attacks, such as APTs, are in it for the long run. After gaining access to an organization’s systems, they use sophisticated techniques to conceal themselves, evade detection, and create a long-term foothold.

The long-term access provided by these APT attacks enables the threat actors to achieve different goals than a hit-and-run attack. With longer-term access, the attacker can steal more data or perform more sophisticated attacks than is possible with more opportunistic attacks.

What Defines an APT?

Other threat actors can perform a sophisticated attack or an extended one. APTs are defined by a few features, including:

  • Expertise: APTs typically involve teams of high-level or expert cyber threat actors. Often, these are groups collected or trained by nation-states or organized crime rather than a “lone wolf” cybercriminal.
  • Resources: APTs typically perform extended attacks before they reach a potential payoff. This — and the ability to perform very sophisticated attacks — means that the groups have significant resources supporting them.
  • Long-Term Mindset: An APT is not a smash-and-grab attack. An attacker may be present in a target environment for months or years collecting information or maneuvering to gain the access needed to achieve their goals.
  • Sophisticated Attacks: APTs typically involve multi-stage attacks with long timelines. These staged attacks make it more difficult for defenders to trace back the attack chain to the initial infection vector.

The APT Security Threat

No organization is completely secure against cyberattacks. Every company has vulnerabilities that an attacker can exploit given sufficient time, patience, and resources.

Most cyberattacks are posed by cyber threat actors looking for “low-hanging fruit.” If an organization hasn’t applied a patch for a well-known vulnerability, they are likely to be exploited by a group pushing ransomware or botnet malware or looking to perform a quick data breach. Implementing good cybersecurity hygiene and best practices eliminates most of the risk posed by these attacks.

APT groups are the attackers willing to put in the time and effort required to identify and exploit a vulnerability in a particular target. Often, these advanced groups have motivations that help in selecting their targets. For example, a nation-state group might target certain organizations for the purpose of espionage or sabotage.

Protecting Against APTs

APT groups are willing to exploit the same simple vulnerabilities as other threat actors. However, implementing basic cybersecurity hygiene isn’t enough to protect against them. For example, if an organization has no unpatched vulnerabilities, the group may turn to sophisticated spear phishing and social engineering attacks to gain access.

In addition to implementing preventative cyber defenses, a key component of managing APTs is accepting that attackers will get in and ensuring that the organization is able to respond effectively. Ongoing monitoring and robust incident response protocols are essential to finding and remediating an intrusion as quickly as possible to minimize the cost and damage to the organization.


APTs are a more subtle, sophisticated threat to an organization than the typical cyber threat actor. Managing APT security risks involves not only implementing cybersecurity best practices but also developing a strong security culture and threat detection and response capabilities.

KZero Staff

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