Initial Access - secuguru/security-terms GitHub Wiki

Initial access is the phase in which attackers first gain unauthorized entry into a target environment. This stage sets the foundation for further exploitation and persistence within the system. Attackers use a variety of methods to achieve initial access, including phishing, hardware placements, supply chain compromise, and exploiting public-facing applications.

1. Phishing

  • Definition: Phishing is a social engineering technique in which attackers send fraudulent messages (usually emails) that appear to come from a legitimate source to deceive users into revealing sensitive information or executing malicious actions.
  • Types of Phishing:
    • Email Phishing: Attackers send emails that mimic trusted contacts or services, often containing malicious links or attachments.
    • Spear Phishing: Targeted phishing that is personalized for specific individuals or organizations, increasing its likelihood of success.
    • Whaling: Aimed at high-profile individuals like executives, typically with more elaborate pretexting to bypass security controls.
  • Security Implications: Phishing is one of the most common initial access methods because it exploits human vulnerabilities rather than technical flaws, bypassing even the most advanced system defenses if users fall for it.

2. Hardware Placements

  • Definition: Hardware placements involve physically deploying devices, such as malicious USBs, keyloggers, or rogue Wi-Fi access points, within or near the target’s environment to gain access to their network or devices.
  • Common Hardware Tactics:
    • Malicious USB Drives: These can be loaded with malware and left in common areas to tempt users to plug them into their computers.
    • Keyloggers: Small devices attached to keyboards that capture keystrokes, often used to harvest login credentials or other sensitive data.
    • Rogue Access Points: Attackers set up unauthorized Wi-Fi access points to intercept network traffic and capture credentials or session tokens.
  • Security Implications: Hardware placements require physical proximity, making them less common but highly effective against physical security gaps. This method can allow attackers to bypass network controls entirely by creating direct access points.

3. Supply Chain Compromise

  • Definition: Supply chain compromise involves infiltrating a target by exploiting vulnerabilities in third-party suppliers or partners, such as software vendors, hardware providers, or service contractors.
  • How It Works:
    • Attackers may compromise software updates, firmware, or other resources delivered by third-party vendors, embedding malicious code that is then distributed to the target.
    • For example, attackers might inject malware into software updates that are automatically deployed by an IT vendor.
  • Security Implications: Supply chain attacks can bypass internal defenses since the compromised third-party components are often trusted by default. This method is challenging to defend against and can have widespread impact, as seen in attacks like the SolarWinds incident.

4. Exploit Public-Facing Applications

  • Definition: Attackers target vulnerabilities in applications or systems that are accessible over the internet, such as web applications, VPNs, or email servers.
  • Types of Exploits:
    • Code Injection: Attackers inject malicious code (e.g., SQL injection, XSS) into vulnerable applications to gain unauthorized access or execute arbitrary commands.
    • Unpatched Vulnerabilities: Public-facing systems that aren’t patched for known vulnerabilities become easy targets.
    • Brute-Force and Credential Stuffing: Attackers may attempt to gain access by repeatedly trying passwords or leveraging stolen credentials.
  • Security Implications: Since these applications are directly exposed to the internet, they represent a significant risk if not secured. Successful exploitation can grant attackers a direct entry point into the network, bypassing many internal security layers.

Summary

  • Phishing leverages social engineering to trick users into providing access, often bypassing system defenses by exploiting human vulnerabilities.
  • Hardware Placements take advantage of physical access to insert malicious devices that provide a direct entry point to systems.
  • Supply Chain Compromise allows attackers to enter networks indirectly by compromising trusted third-party vendors, often bypassing standard defenses.
  • Exploiting Public-Facing Applications targets internet-exposed vulnerabilities, enabling attackers to gain access remotely without needing internal or physical access.

By understanding these initial access tactics, organizations can implement preventive measures like user education, physical security controls, robust patch management, and supply chain risk assessments to help mitigate the risk of initial compromise.