Table of Contents
Phishing (Email Security)
Phishing is a social engineering attack where malicious actors impersonate legitimate individuals, organizations, or brand entities via email to trick recipients into revealing sensitive information (such as passwords, financial credentials, or private keys), downloading malware, or executing fraudulent wire transfers.
Because email protocols were not originally designed with identity verification built-in, phishing remains one of the primary vectors for initial access in cybersecurity breaches.
Common Types of Phishing Attacks
| Attack Vector | Target Audience | Description & Method |
|---|---|---|
| Standard Phishing | Mass Recipients | Generic, automated emails masquerading as major services (e.g., banks, cloud providers) to harvest credentials. |
| Spear Phishing | Targeted Individuals | Highly customized emails leveraging gathered OSINT (Open Source Intelligence) about a specific target or department. |
| Whaling | High-Level Executives | Targeted attacks aimed at CEOs, CFOs, or administrators to authorize large financial transactions or grant elevated privileges. |
| Business Email Compromise (BEC) | Finance / HR Departments | Impersonation of trusted executives, vendors, or business partners to divert invoice payments or intercept sensitive employee data. |
| Clone Phishing | Service Users | Intercepting or copying a legitimate, previously sent email and replacing links/attachments with malicious payloads. |
Common Phishing Mechanisms & Indicators
Phishing attacks rely on technical deception to bypass human scrutiny and automated security filters:
1. Domain & Sender Spoofing
Attacker sends an email with a fake `From:` header displaying a trusted brand (e.g., `support@bank.com`), while the email originates from an unauthorized mail server.
- *For detailed technical countermeasures, see Email Spoofing.*
2. Lookalike / Cousin Domains (Typosquatting)
Attackers register domains that visually resemble legitimate brand domains (e.g., using `teleneqar.ir` or `telenegar-security.ir` instead of `telenegar.ir`).
3. IDN Homograph Attacks
Using internationalized domain names (IDN) with lookalike Cyrillic or Greek characters that mimic Latin characters in web browsers and mail clients.
4. Malicious Hyperlinks & Credential Harvesting
Emails contain links directing users to rogue landing pages designed to look identical to legitimate login portals. Links often use open redirects or URL shorteners to mask the final destination.
Technical Defense Strategy
Preventing phishing requires a layered defense combining DNS-based email authentication protocols and inbound filtering security.
1. Deploy the Core Email Authentication Stack
Implementing strict email authentication ensures unauthorized servers cannot spoof your domain in phishing campaigns:
- SPF (Sender Policy Framework) — Defines authorized sending IP addresses for your domain.
- DKIM (DomainKeys Identified Mail) — Cryptographically signs messages to guarantee authenticity and content integrity.
- DMARC (Domain-based Message Authentication) — Establishes policy rules (`p=quarantine` or `p=reject`) instructing receiving servers to block emails that fail SPF or DKIM alignment.
<note warning> Without a strict DMARC policy (`p=quarantine` or `p=reject`), attackers can freely forge your domain name in outbound phishing messages sent to your customers or partners. </note>
2. Implement BIMI for Brand Verification
Deploying BIMI displays your official trademarked logo directly in recipient inboxes, helping users quickly distinguish legitimate communications from phishing attempts.
3. Inspect Inbound Email Headers
Train security teams and automated filters to inspect Email Headers:
- Check the `Authentication-Results:` header for `spf=fail`, `dkim=fail`, or `dmarc=fail`.
- Compare the `From:` header domain with the actual `Return-Path:` (Envelope From) address and originating server IP.
Verification & Diagnostics with Telenegar
Audit your domain's anti-phishing defense posture using Telenegar Tools:
Using Telenegar Tools
- Email Security Audit: Check if your domain is protected against spoofing with the Telenegar Mail Check Tool.
- DNS Authentication Records: Verify your SPF, DKIM, and DMARC TXT records globally with the Telenegar DNS Check Tool.
Related Documentation
- Telenegar Mail Check Tool — Test your domain's resistance to email spoofing and phishing vulnerabilities.
- Telenegar DNS Check Tool — Inspect email authentication DNS records.
- Email Spoofing — In-depth guide on domain spoofing mechanics and prevention.
- DMARC — Essential policy framework for preventing domain misuse.
- BIMI — Visual brand identification for verified email.
- Email Headers — Learn how to parse raw headers to investigate phishing attempts.