Advanced Phishing Defense — Module 3 (Premium)

🎯 Advanced Phishing Defense — Module 3

Premium Theory + Real Example + 18-Question Quiz Difficulty: Professional

1) Theory — Modern phishing: beyond bad English

Today’s phishing is polished and multi-channel: email (BEC/spear/whaling), SMS (smishing), voice (vishing), QR codes (QRishing), and consent-phishing via OAuth. Attackers spoof brands and executives, abuse look-alike domains (homograph attacks), and bypass MFA with adversary-in-the-middle (AitM) kits. Effective defense is identity-first, content-aware, and behavior-driven — not just “hover over the link.”

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Key points (at a glance):
  • BEC & spear: tailored messages to finance/execs for payment or data fraud.
  • MFA bypass: AitM proxies, push-fatigue, and session token theft.
  • Consent-phishing: users grant OAuth scopes; no password is stolen.
  • HTML smuggling: payload hides inside HTML/JS and reconstructs on the endpoint.
  • Defense: phishing-resistant MFA, mail authentication (SPF/DKIM/DMARC), sandboxing, DLP, user drills.

1.1 Common techniques

  • Brand impersonation & look-alike domains: typos, homoglyphs, subdomain tricks.
  • Adversary-in-the-middle (AitM): reverse-proxy captures credentials and MFA tokens.
  • QRishing: QR codes in emails/posters leading to malicious portals.
  • Thread hijacking: reply-chain abuse from compromised mailboxes.
  • HTML smuggling: downloads assembled client-side to evade gateways.

1.2 Targets & psychology

  • Urgency & authority: “CEO needs this now,” “past-due invoice.”
  • Curiosity & fear: “missed delivery,” “account disabled,” “unusual login.”
  • Financial ops: AP/AR, payroll, procurement — highest BEC impact.

1.3 Technical controls that actually help

  • SPF/DKIM/DMARC: authenticate mail; quarantine/reject failed or unauthenticated spoofing.
  • Phishing-resistant MFA: FIDO2/Passkeys, number-matching prompts; limit SMS.
  • Secure mail gateway / sandbox: detonate attachments/URLs; rewrite and time-of-click analysis.
  • URL defense & blocklists: strip/mangle known malicious TLDs/shorteners; intelligence feeds.
  • Attachment policy: block dangerous types; convert office docs to safe formats.
  • Mailbox rules guard: alert on suspicious forwarding and hidden rules.
  • Browser isolation (high-risk roles): isolate unknown sites for finance/execs.

1.4 Human layer & process

  • Report button: one-click report to security; reward reporting, not perfection.
  • Out-of-band verification: phone/Teams call on payment or bank-detail changes.
  • Just-in-time nudges: banners on external email, financial requests, or new domains.
  • Playbooks & drills: quarterly phishing simulations; tabletop for BEC escalation.

1.5 Incident playbook (suspected phish/BEC)

  1. Preserve & report: don’t forward to colleagues; use the report button or forward to security mailbox.
  2. If clicked/credentialed: reset password; revoke sessions; enforce MFA re-enrollment; check inbox rules.
  3. If money requested: halt payments; verify via independent channel; notify bank if transfer sent.
  4. Scope & contain: review sign-ins, OAuth consents, file sharing, mail forwarding; disable risky apps.
  5. Communicate: brief finance/executives; coordinate with legal on notifications if data accessed.
  6. Improve: tune gateway rules, DMARC policy, and user training based on the event.
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2) Real-world example

Vendor email compromise (VEC) to invoice fraud: Attackers phished a small supplier’s mailbox, studied real threads, then sent a “bank details update” to a customer’s AP team using the ongoing thread. The email passed SPF/DKIM because it came from the real supplier domain. The customer wired €142,000 to the attacker’s IBAN. The loss was stopped only after finance added out-of-band verification for any bank-detail change and mail rules were added to alert on payment-keyword threads.

3) Assessment — 18 Professional Questions

Choose the best answer for each question. Answers and feedback appear after you submit.

1) Which control best reduces MFA push-fatigue attacks?

2) AitM kits primarily aim to steal:

3) Strongest mail authentication posture for your domain?

4) Which scenario most likely indicates consent-phishing?

5) Best protection against look-alike domain phishing?

6) Which user behavior should always trigger out-of-band verification?

7) HTML smuggling helps attackers to:

8) Strongest defense against AitM credential theft?

9) Which gateway feature helps most at click time?

10) You detect a mailbox rule that hides external replies. First action?

11) Which email banner is most useful?

12) Which users should get stricter controls by default?

13) Which change best limits damage from successful phish?

14) You suspect QRishing posters in the office. Best control?

15) Which is the best verification step for bank-detail changes?

16) Which signal in logs best flags reply-chain hijacking?

17) What should a “Report Phish” button do?

18) A CFO gets an urgent “CEO wire request” while the CEO is on a flight. Best action?

4) Finish

When you’re done, mark this module as completed to update your Premium Hub progress.

✅ Mark this module complete

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