The EC-Council Incident Handler (ECIH) curriculum classifies social engineering as a human-based attack technique that manipulates individuals into disclosing confidential information without exploiting technical vulnerabilities. In this scenario, the attackers first gathered publicly available information—also known as Open-Source Intelligence (OSINT)—by mining executive digital footprints, analyzing online publications, and reviewing external mentions. This reconnaissance phase aligns directly with OSINT-based profiling.

The adversaries then conducted scripted interviews under fabricated personas to extract additional identifiers. This behavior is characteristic of pretexting, a specific social engineering technique where attackers create a false scenario to persuade victims to provide sensitive information. ECIH explains that pretexting often involves impersonation and carefully constructed narratives to build credibility and trust.

The absence of malware infection or system-level compromise further confirms that this was not a technical exploit such as phishing with malicious macros (Option A) or pharming (Option C). Additionally, skimming (Option D) is a physical data theft technique unrelated to executive impersonation or digital profiling.

ECIH emphasizes that insider threat and financial fraud investigations frequently reveal social engineering campaigns leveraging OSINT, impersonation, and psychological manipulation rather than malware. Preventive controls include executive awareness training, strict identity verification for financial change requests, multi-factor authentication, and callback verification procedures.

Therefore, the technique that best aligns with the adversary’s method is social engineering using open-source intelligence followed by pretexting.