Introduction

Penetration Testing is a fundamental mechanism for evaluating the security of information systems by simulating targeted attacks. Unlike IT Security Audits, the goal of a Penetration Test is to uncover real, exploitable vulnerabilities and assess risk based on realistic attack scenarios.

Methodology

The process typically begins with an assessment of critical infrastructure components such as firewalls, Active Directory, SQL, and email/web servers. Automated tools are used initially to identify known vulnerabilities, followed by active exploitation by a specialized team. This team targets weaknesses stemming from misconfigurations, functional flaws, or design issues. The final output includes documentation of the risks along with specific remediation recommendations.

Attack Scenarios and Findings

In real-world scenarios, attacks often begin with phishing campaigns. From simple emails with deceptive links to advanced techniques like whaling and social media phishing, ethical hackers aim to obtain credentials. Once initial access is gained, attackers move laterally through the network and maintain persistence, often using obfuscation techniques to avoid detection.

When vulnerable services are exposed to the internet—such as web applications or email servers—remote exploitation can occur due to insufficient hardening or faulty ACLs. Insider threats or third-party risks are also significant concerns. Supply chain attacks are increasingly common, including scenarios such as bribing employees or misuse of access by Managed Service Providers. Third-Party Risk Management is now considered one of the greatest challenges in cybersecurity.

Advanced Phishing Techniques and Mitigation

Modern phishing attacks employ methods that bypass traditional defense mechanisms. A poorly configured mail server without proper SPF, DKIM, or DMARC implementations provides attackers with an advantage. Additional tactics include bypassing antispam filters through keyword manipulation or crafting login pages that closely mimic legitimate ones.

Mitigation requires a multi-layered defense strategy. Using MFA, AI-driven antispam systems, and continuous user awareness training is vital. DNS-level protection and breached-password blacklists add an extra layer of security.

Common Findings in Internal Penetration Tests

Internal tests often reveal recurring vulnerabilities exploitable by attackers. One of the most frequent is the presence of unsupported or outdated software—such as old versions of iDRAC or ILO. Misconfigured access permissions on file servers and incorrect VLAN setups that allow unauthorized movement across the network are also common.

Weak password policies remain widespread, with reused credentials often found across multiple services. Decommissioned systems and applications that haven’t been fully removed can still be accessible, acting as potential entry points.

Other findings include unrestricted access to resources like printers and scanners, flawed domain policies, and access to iSCSI targets without any form of authentication.

Effectiveness of Detection & Response Technologies

The continuous development of EDR, XDR, and NDR solutions has significantly improved the ability to detect and prevent malicious activity. In many cases, even when exploitable vulnerabilities existed, they could not be leveraged due to the immediate response of detection and response systems. Attempts to capture hash dumps or install reverse shells, for instance, were detected and blocked in real time.

However, the effectiveness of these technologies heavily depends on well-crafted detection rules and thorough monitoring of user and endpoint behavior. Activities such as rapid network mapping or extensive PowerShell use may trigger isolation or automatic blocking mechanisms.

In some environments, extremely strict network monitoring policies may limit the functionality of Vulnerability Assessment tools, as any deviation from typical behavior is aggressively flagged and filtered.

Penetration Test vs. IT Security Audit

It is crucial to distinguish between compliance audits and penetration testing. IT Security Audits identify weaknesses based on policies and procedures through configuration assessments, while Penetration Tests evaluate a system’s resilience to real attacks. The combination of both offers the most realistic approach for organizations seeking to effectively strengthen their cybersecurity posture.

Conclusion

In our experience, the majority of successful intrusions are due to human error and neglected updates. Security is not a static state but an ongoing process of evaluation, prevention, and adaptation. Penetration Testing is an integral part of this process and should be conducted systematically as part of a broader organizational defense strategy.

Source: https://simasecurity.gr/en/common-findings-in-penetration-tests-a-technical-review/