Which two factors make Business Email Compromise (BEC) attacks difficult to detect?

BEC is difficult to detect primarily because it often lacks “traditional malware signals” and instead relies on human deception. Social engineering (C) is core: attackers craft believable narratives (invoice urgency, legal requests, gift card scams, payroll changes) tailored to organizational context. Impersonation (D) is the second pillar: display-name spoofing, lookalike domains, compromised vendor accounts, and executive/finance role impersonation. These tactics can produce messages that are text-only, low-volume, and free of obviously malicious attachments/URLs, making signature-based or URL reputation controls less effective. Proofpoint-specific defenses therefore emphasize identity and relationship signals (impostor detection, supplier risk, unusual sending patterns), authentication (SPF/DKIM/DMARC alignment), and behavioral context (who typically emails whom, anomalies in reply chains, newly observed domains). In IR, analysts triage BEC by validating headers, checking domain age and similarity, confirming invoice/payment workflows out-of-band, and scoping for mailbox compromise (rules/forwarding, suspicious OAuth grants). Because BEC “looks normal” at the technical layer, effective detection requires combining Proofpoint telemetry with process controls and fast escalation to business stakeholders.