Understanding Business Email Compromise (BEC) – A Small‑Business Guide

What Is Business Email Compromise?

Business Email Compromise (or BEC) is a form of cyber‑fraud where attackers impersonate a trusted person—often a company executive, accountant, or vendor—to trick employees into sending money, revealing confidential data, or changing payment details. Unlike generic phishing, BEC attacks rely heavily on social engineering and the credibility of internal communications, making them especially dangerous for small businesses that may have fewer layers of oversight.

Typical BEC scenarios include:

Scenario	How It Works
CEO‑spoof	An attacker sends an email that looks like it came from the CEO, asking the finance team to wire funds to a new account.
Invoice fraud	A fake invoice appears to come from a regular supplier, with slightly altered bank details.
Account takeover	The attacker steals an employee’s credentials, logs into the real mailbox, and forwards a “urgent” request to another department.
Data exfiltration	A seemingly innocuous request for HR records or client contracts is sent from a compromised account.

Because the messages appear to come from familiar contacts, the red flags are often subtle—minor typos, odd phrasing, or unexpected urgency.

Why Small Businesses Are Targets

• Limited resources: Fewer dedicated IT or security staff means fewer technical controls and less frequent training.

• Tight-knit relationships: Employees often act on requests from known colleagues without double‑checking.

• Financial impact: Even a single successful BEC scam can drain a small business’s cash flow or damage its reputation.

Six Practical Steps to Reduce Your BEC Risk

Below is a concise, actionable checklist you can start implementing today. Each step balances effectiveness with the reality of limited budgets and staff.

1. Lock Down Email Authentication (DMARC, DKIM, SPF)

• What to do: Publish SPF and DKIM records for your domain and set a strict DMARC policy(p=reject). This tells receiving servers to reject messages that aren’t properly authenticated.

• Why it helps: Attackers can no longer spoof your domain to send fraudulent emails to partners or customers.

• How to start: Many domain registrars and hosting providers have built‑in wizards. If you use Proton Mail or Proton Drive for business, the settings are already enforced—just confirm they’re active.

2. Enforce Multi‑Factor Authentication (MFA) Everywhere

• What to do: Require MFA for every email account, especially anyone with financial authority (e.g., CFO, accounts payable).

• Why it helps: Even if a password is stolen, the attacker still needs a second factor (hardware token, authenticator app, or push notification) to log in.

• Tip: Use a password‑less solution like a FIDO2 security key for senior staff; it’s cheap, easy to manage, and eliminates weak passwords.

3. Create a Dual‑Approval Process for Payments

• What to do: No single person should be able to change vendor bank details or approve large transfers. Set up a workflow where at least two independent employees must approve any payment over a defined threshold (e.g., $1,000).

• Why it helps: An attacker who compromises one mailbox still can’t move money without a second, verified sign‑off.

• Implementation: Simple tools like Google Workspace’s “approval” add‑on, Microsoft Power Automate, or even a shared spreadsheet with version control can serve this purpose.

4. Train Your Team with Realistic Simulations

• What to do: Run quarterly phishing simulations that mimic BEC tactics (CEO‑spoof, invoice changes). Follow each test with brief, constructive feedback.

• Why it helps: Employees learn to pause, verify, and report suspicious requests rather than acting impulsively.

• Low‑cost options: Free phishing‑simulation services (e.g., GoPhish) can be hosted on a modest cloud instance. Or partner with a local IT consultant for occasional drills.

5. Verify Any Change in Payment Details Out‑of‑Band

• What to do: Whenever a vendor asks to update banking information, call the vendor using a known phone number (not the one in the email) to confirm.

• Why it helps: Even a perfectly forged email can’t replicate a voice conversation or a pre‑established verification code.

• Best practice: Document the verification step in your SOPs so it becomes a habit, not an afterthought.

6. Monitor Email Activity and Set Up Alerts

• What to do: Enable logging of mailbox rule changes, forwarding rules, and logins from new locations. Use a lightweight SIEM or even a free alert service that notifies you of abnormal activity.

• Why it helps: Early detection of a compromised account lets you lock it down before an attacker can execute a BEC scheme.

• Quick win: Proton Mail’s “Security Dashboard” shows recent login locations and alerts for suspicious behavior—review it weekly.

Bonus Tips for Small Teams

Tip	Quick Action
Secure password recovery	Disable self‑service password resets for privileged accounts; require IT verification.
Protect remote work	Adopt a zero‑trust model: only allow email access from managed devices that meet security baselines.
Vendor security alignment	Ask your suppliers to publish their own DMARC policy and use MFA—mutual protection strengthens the entire supply chain.
Incident playbook	Draft a short BEC response plan: who to call, how to isolate the compromised mailbox, and how to notify banks. Keep it under one page.

Bottom Line

Business Email Compromise isn’t a “big‑company only” problem. With a few focused measures—strong email authentication, mandatory MFA, dual‑approval for payments, regular training, out‑of‑band verification, and vigilant monitoring—you can dramatically shrink the attack surface for your small business.

Take one step today: check whether your domain has a DMARC policy set to “reject.” If not, update it now or ask your email provider for help. From there, build the other safeguards gradually. The effort you invest now can save you from costly fraud, reputational damage, and sleepless nights later.