Business Email Compromise (BEC) Attempt Detection

This rule detects potential Business Email Compromise (BEC) attempts by identifying emails where the sender's address contains keywords like 'ceo', 'finance', or 'hr', and the subject contains keywords like 'wire', 'payment', or 'invoice', but the sender's domain does not match the internal company domain. This pattern suggests an attempt to impersonate a high-ranking individual or department to trick recipients into making unauthorized financial transactions.