mime-targ-atta-prtc

name	mime-targ-atta-prtc
description	Deploy Mimecast Targeted Threat Protection including URL Protect, Attachment Protect, Impersonation Protect, and Internal Email Protect to defend against advanced phishing and spearphishing attacks.
domain	cybersecurity
subdomain	phishing-defense
tags	["mimecast","email-security","targeted-threat-protection","url-protect","impersonation","attachment-sandboxing","phishing"]
version	1.0
author	mahipal
license	Apache-2.0
nist_csf	["PR.AT-01","DE.CM-09","RS.CO-02","DE.AE-02"]

Implementing Mimecast Targeted Attack Protection

Overview

Mimecast Targeted Threat Protection (TTP) is a suite of advanced email security services designed to protect against sophisticated phishing, spearphishing, and targeted attacks. TTP consists of four core modules: URL Protect (real-time URL rewriting and click-time analysis), Attachment Protect (sandbox detonation of suspicious attachments), Impersonation Protect (BEC and whaling detection), and Internal Email Protect (scanning internal/outbound email for threats). As of November 2025, Mimecast enabled URL Pre-Delivery Action with Hold setting for all customers by default.

When to Use

• When deploying or configuring implementing mimecast targeted attack protection capabilities in your environment
• When establishing security controls aligned to compliance requirements
• When building or improving security architecture for this domain
• When conducting security assessments that require this implementation

Prerequisites

• Mimecast Email Security license with TTP add-on
• Administrative access to Mimecast Administration Console
• Microsoft 365 or Google Workspace environment
• MX records configured to route through Mimecast
• Understanding of email authentication (SPF, DKIM, DMARC)

Key Concepts

TTP Module Overview

Module	Function	Key Capability
URL Protect	Rewrites and scans URLs at click time	Real-time sandbox, pre-delivery hold
Attachment Protect	Sandboxes suspicious attachments	Static + dynamic analysis
Impersonation Protect	Detects BEC/whaling attacks	VIP name matching, header analysis
Internal Email Protect	Scans internal/outbound email	Lateral phishing detection

Impersonation Protection Scenarios

• Hit 3 (Default): Flags emails matching 3+ impersonation indicators
• Hit 1 (VIP): Flags emails matching 1+ indicator for designated VIP users
• Key identifiers: display name similarity, domain similarity, reply-to mismatch, newly registered domains

URL Protect Modes

• Rewrite: URLs rewritten to route through Mimecast proxy at click time
• Pre-Delivery Action (Hold): URLs checked before message delivery; held if suspicious