What are APTs (Advanced Persistent Threats) & How Do They Attack?

Advanced Persistent Threats (APTs) are highly sophisticated, stealthy cyberattacks that target governments, enterprises, and critical infrastructure. These attacks are often state-sponsored or linked to cybercriminal groups and aim for long-term espionage, data theft, or disruption.

Here’s a step-by-step breakdown of how APTs attack:

1. Initial Reconnaissance (Information Gathering)

Attackers research their target to understand its network, employees, supply chain, and vulnerabilities.

• They gather intel through OSINT (Open-Source Intelligence), social media, leaked credentials, and dark web sources.
• Sometimes, they use passive scanning to identify weak spots in web servers, emails, or employee behaviors.

Example: APT groups study an energy company's organizational structure through LinkedIn and scan for exposed systems.

2. Initial Compromise (Gaining Access)

Attackers exploit vulnerabilities or use social engineering to gain a foothold.

Common techniques:

• Spear phishing – Sending targeted, malicious emails with infected attachments or links.
• Watering Hole Attacks – Injecting malware into trusted websites that employees visit.
• Zero-day Exploits – Using unknown software vulnerabilities to infiltrate.
• Supply Chain Attacks – Compromising third-party vendors to access the target.

Example: APT hackers send an email disguised as an IT update, tricking an employee into opening a malicious file.

3. Establishing a Foothold (Creating Persistence)

• Once inside, APTs deploy malware, backdoors, or rootkits to maintain access.
• They may use Remote Access Trojans (RATs) to control infected systems remotely.
• They often disable antivirus tools, create hidden admin accounts, and blend into normal traffic.

Example: Attackers install a backdoor on a compromised server, allowing them to return undetected.

4. Internal Reconnaissance & Lateral Movement

Attackers move laterally across networks, escalating privileges.

They scan for sensitive files, domain controllers, and privileged accounts.

Techniques include:

• Pass-the-Hash – Using stolen password hashes to access other systems.
• Credential Dumping – Extracting login credentials from memory.
• Living Off the Land (LotL) Attacks – Using built-in system tools (PowerShell, WMI) to avoid detection.

Example: Attackers steal an admin’s login details and use them to access confidential documents.

5. Data Exfiltration & Mission Execution

Once attackers find their target data, they stealthily extract it.

Data is often compressed and exfiltrated in small, encrypted chunks to avoid detection.

Exfiltration methods:

• DNS tunneling – Hiding data inside DNS traffic.
• Cloud services abuse – Uploading stolen data to Google Drive, Dropbox, or compromised FTP servers.
• Steganography – Hiding data inside images or other files.

Example: APT hackers slowly transfer trade secrets to an offshore command-and-control (C2) server.

6. Covering Tracks & Maintaining Access

• Attackers erase logs, modify timestamps, and disable security alerts.
• They may install multiple backdoors for future access.
• In some cases, they launch destructive attacks (e.g., ransomware, wipers) to cover their exit.

Example: Attackers delete event logs and disable audit trails before leaving.

Common APT Attack Groups & Tactics

Notable APT Groups:

• APT41 (China) – Cyber-espionage & financial theft.
• Lazarus Group (North Korea) – Cryptocurrency theft & sabotage.
• Fancy Bear (Russia) – Government & military espionage.
• Charming Kitten (Iran) – Targeting media & dissidents.

Common Tactics (MITRE ATT&CK Framework):

• T1193 – Spear Phishing
• T1071 – Command & Control (C2) Communication
• T1086 – PowerShell Execution
• T1562 – Anti-Forensic Techniques

How to Defend Against APT Attacks

Key Defenses:

• Threat Intelligence – Stay updated on APT tactics and indicators of compromise (IOCs).
• Zero Trust Architecture – Assume no user or device is trusted by default.
• Endpoint Detection & Response (EDR) – Monitor abnormal activity.
• Regular Patching – Fix vulnerabilities before they’re exploited.
• Security Awareness Training – Educate employees on phishing and social engineering.
• Network Segmentation – Restrict lateral movement within IT environments.
• Multi-Factor Authentication (MFA) – Strengthen login security.

APTs don’t just attack and leave — they persist for months or years, causing long-term damage. Organizations need proactive threat hunting, real-time detection, and strong cybersecurity defenses to counter these advanced adversaries.

If you would like to know how TeamT5, a threat intelligence and threat hunting leader could help you increase your organization's security posture, please reach out to me at [email protected].