Introduction to External Penetration Testing
In today’s digital-first world, organizations are increasingly vulnerable to cyberattacks. In fact, according to a recent report by Cybersecurity Ventures, global cybercrime costs are projected to reach $10.2 trillion annually by 2025.
As such, external penetration testing is a critical component of a comprehensive cybersecurity strategy. It provides a proactive approach to identifying vulnerabilities and potential attack vectors before malicious actors can exploit them. In this write-up, we will explore its applications and differences in techniques. So, let’s get started!
What is External Penetration Testing (EPT)?
External penetration testing is a process that simulates real-world attacks originating from outside of your organization’s networks and systems. It is conducted by an external security team free of biases that an in-house team may have and encompasses a detailed source code review and manual inspections.
It is often conducted on targets such as web and mobile apps, cloud infrastructures, network & IOT devices with varying depths, depending upon the scope of testing and your security needs.
Note: Penetration testing of systems accessible via the Internet is also often called external penetration testing. These external systems typically include web applications, networks, routers, switches, subdomains, and login systems. This type of testing is commonly known as Network penetration testing.
Internal vs External Pen Testing
| Features | Internal Penetration Testing | External Penetration Testing |
|---|---|---|
| Team | Internal penetration testing is done by in-house security experts. | External penetration testing is done by an independent team of security researchers. |
| Cost | It can be costly to maintain a full-time security team. | It is cost-effective to outsource security testing. |
| Perspective | Since in-house security researchers know the ins & outs of a system, they often struggle to look at it from a hacker's perspective. | External penetration testing offers a fresh perspective on the system's security and is great at emulating a hacker’s behavior on the target system. |
| Frequency | Internal penetration testing requires less planning and can be done more frequently. | Since it’s an outside engagement, it is time taking to conduct frequently. Check out this blog to get an idea of how much penetration testing costs. |
| Compliance | Internal penetration testing does not suffice in compliance requirements. | External penetration testing is necessary to comply with various compliances. |
Steps in External Penetration Testing
An external penetration test is a cybersecurity assessment
designed to simulate real-world attacks originating from outside an
organization's network perimeter, targeting publicly exposed systems and
assets. This type of test helps businesses identify and address vulnerabilities
before malicious actors can exploit them.
Here are the key steps involved in an external
penetration test:
1. Pre-Engagement and Planning:
- Define
Scope and Objectives: This phase involves the client and the
penetration testing team agreeing on the goals of the test, the specific
systems and assets to be included, and the type of testing to be conducted
(e.g., black box - no prior knowledge, white box - full knowledge).
- Establish
Rules of Engagement: Clear guidelines are set for the tester's
actions and acceptable methods, ensuring no disruptions or damage to the
target systems.
- Legal
Agreements: Non-disclosure agreements (NDAs) and other legal
documents are signed to protect sensitive information.
2. Reconnaissance:
- Information
Gathering: Testers passively collect information about the target
organization and its external infrastructure using publicly available
sources (e.g., DNS records, WHOIS data).
- Asset
Identification: Identifying publicly accessible assets like websites,
servers, routers, and login systems.
3. Scanning:
- Vulnerability
Scanning: Automated tools are used to scan identified assets for
known vulnerabilities and misconfigurations.
- Port
Scanning: Identifying open ports and services running on external
systems.
4. Vulnerability Analysis and Exploitation:
- Manual
Testing: Penetration testers manually analyze the findings from the
automated scans to confirm vulnerabilities and assess their potential
impact.
- Exploitation
Attempts: Testers attempt to exploit identified vulnerabilities to
gain unauthorized access to systems or data, mimicking real-world attacks.
- Privilege
Escalation: If successful, testers attempt to gain higher levels of
access within the compromised system.
- Data
Exfiltration (Optional): In some cases, testers may attempt to
simulate data theft to demonstrate the potential impact of a successful
breach.
5. Post-Exploitation (If Exploitation is Successful):
- Maintaining
Access: Establishing a persistent presence within the compromised
system to simulate ongoing access.
- Lateral
Movement: Moving from the initially compromised system to other
systems within the network.
6. Reporting:
- Detailed
Report: A comprehensive report is prepared outlining the findings,
including identified vulnerabilities, the methods used to exploit them,
and the potential impact.
- Recommendations: Actionable
recommendations for remediation are provided to address the identified
vulnerabilities and strengthen the organization's security posture.
7. Remediation and Retesting:
- Remediation: The
organization implements the recommended security measures to address the
vulnerabilities.
- Retesting: The
penetration testing team retests the systems to ensure the remediation
efforts have been effective.
Note: External penetration testing differs from
vulnerability scanning in that it goes beyond simply identifying
vulnerabilities and actively attempts to exploit them to demonstrate the
real-world risk. Astra Security provides a comparison, stating. Pen testing
also typically involves a higher degree of manual testing and expertise
compared to vulnerability scanning.