advanced persistent threat (APT)

Charlie Yianni

min read

What is an Advanced Persistent Threat (APT)?

An Advanced Persistent Threat (APT) is a sophisticated, targeted cyberattack in which an attacker gains unauthorized access to a network and remains undetected for an extended period. APTs are typically carried out by well-funded and highly skilled threat actors, often for espionage, data theft, or long-term disruption.

What makes APTs different from regular cyberattacks?

Unlike opportunistic attacks, APTs are deliberate, stealthy, and sustained. Attackers choose their targets carefully - often governments, enterprises, or organizations with valuable intellectual property or sensitive data. Once inside, their goal is persistence: to move laterally, escalate privileges, and exfiltrate data while avoiding detection.

Key characteristics of APTs:

Advanced: Attackers use custom malware, zero-day exploits, and social engineering.
Persistent: They maintain long-term access without triggering alarms.
Targeted: APTs are tailored for specific victims, with reconnaissance done beforehand.

What is the primary goal of an APT attack?

The goal of an APT is typically to steal sensitive data, spy on communications, or sabotage systems. Common objectives include:

Intellectual property theft
Access to classified government or corporate information
Financial data exfiltration
Surveillance or influence operations

Unlike ransomware, the aim isn’t quick financial gain - it’s long-term value extraction.

How do APT attacks work?

APT campaigns often unfold over several stages:

Initial Access: Attackers use phishing emails, software vulnerabilities, or compromised credentials to get in.
Establish Foothold: Malware is deployed to maintain access and communicate with command-and-control servers.
Lateral Movement: Attackers move through the network to find higher-value systems or data.
Data Exfiltration: Information is quietly transferred out of the organization.
Persistence: Even after discovery, attackers often maintain access through backdoors or alternate routes.

How can you defend against APTs?

Protecting against APTs requires a layered security strategy, including:

Continuous monitoring: Detect unusual behavior through security analytics and threat detection tools (e.g. SIEM, UEBA).
Vulnerability management: Reduce attack surface by patching known flaws quickly.
Least privilege: Limit access rights to reduce attacker movement.
Multi-factor authentication (MFA): Protect credentials and access.
Threat intelligence: Stay updated on attacker tactics, techniques, and procedures (TTPs).

Where does Intruder fit in?

Intruder helps reduce your risk of falling victim to APTs by:

Continuously scanning your systems for vulnerabilities attackers could exploit
Highlighting high-risk weaknesses based on severity and exploitability
Monitoring for exposure of sensitive services that APT actors often target

Start your free 14-day trial to strengthen your defenses and proactively reduce your attack surface.