Email remains the primary attack vector for initial compromise. Phishing awareness training helps, but attackers continuously adapt. Modern email threats extend far beyond asking recipients to click suspicious links.
Business email compromise targets finance teams with sophisticated social engineering. Attackers research organisational hierarchies, study communication patterns, and impersonate executives. Emails requesting urgent wire transfers appear legitimate, coming from what looks like the CEO’s address.
Domain spoofing exploits mail server misconfigurations. Without proper SPF, DKIM, and DMARC records, attackers send emails appearing to come from your domain. Recipients trust messages from familiar domains, making spoofed emails highly effective.
Conversation hijacking elevates attack sophistication. Attackers compromise email accounts, then monitor ongoing conversations. They insert themselves into existing email threads at strategic moments, requesting wire transfers or sharing malicious attachments. Context makes these attacks devastatingly effective. Professional web application penetration testing includes testing email security controls and authentication mechanisms.
OAuth token theft bypasses password security entirely. Attackers trick users into granting OAuth permissions to malicious applications. These tokens provide access to email and other services without needing passwords. Multi-factor authentication doesn’t prevent this attack vector.
William Fieldhouse, Director of Aardwolf Security Ltd, notes: “Email security requires defence in depth. Technical controls, user awareness, and monitoring all contribute. No single solution stops sophisticated email attacks. Organisations need layers of protection and rapid incident response when attacks succeed despite preventive measures.”
Malicious attachments evolve constantly. Macro-enabled documents remain effective despite years of warnings. Archive files containing executables slip past basic filtering. HTML attachments render malicious JavaScript that some email clients execute automatically.
Link manipulation hides malicious destinations. Attackers use URL shorteners, legitimate-looking domains with slight misspellings, or HTML encoding to disguise malicious links. Hovering over links doesn’t always reveal the true destination, especially on mobile devices.
Calendar invite attacks exploit trusted email mechanisms. Attackers send calendar invitations with malicious links in event descriptions. These invitations often bypass email filters because they’re not traditional email messages. Recipients click links directly from their calendars without scrutiny.
Internal email compromise enables lateral movement. Once attackers control one account, they send phishing emails from that compromised account to colleagues. Internal emails receive less scrutiny than external ones, improving attack success rates.
Advanced threat protection services analyse attachments in sandboxed environments, checking links in real-time, and applying machine learning to detect anomalous email patterns. These services catch threats that traditional spam filters miss. When you request a penetration test quote, ensure the assessment includes social engineering and email security testing.
Incident response for email compromise requires immediate action. Compromised accounts should be disabled, OAuth tokens revoked, and password changed immediately. Reviewing sent items and email rules helps understand attacker actions and prevents continued compromise.
