ATOs are the new BEC. We're seeing it on our end and other companies have certainly taken notice. Attackers compromised 6.2 million customer accounts across 1,027 large organizations in 2024 according to Kasada’s 2025 Account Takeover Attack Trends Report, underscoring how routine ATO incidents have become for enterprise brands. Many of these compromises start with email and stolen credentials. For MSPs, this should be a "light bulb" moment that ATO prevention, detection, and response should be a core part of your managed security offering.
This blog outlines a practical, MSP-ready playbook for helping customers move from compromise to control, then shows how to align those practices with IRONSCALES Advanced Account Takeover (ATO) Protection.
ATOs are no longer isolated events. They have become a predictable pattern. Attackers lean on:
Once inside, they do not need malware or exploits. They use valid credentials and take advantage of trust. They set up mailbox rules, forward mail to external accounts, delete traces of their activity, and slowly pivot toward fraud or data theft.
Recent research on ATO trends shows:
Many targeted organizations already had basic bot or perimeter defenses in place. Attackers simply moved around those controls by rotating IPs, using human solver services, and blending into legitimate login patterns.
ATO is a persistent, behavior driven threat. You cannot rely on static controls at the edge. You need protection that understands real user behavior inside the mailbox.
An effective ATO strategy for MSPs rests on three pillars:
Each pillar needs to be concrete enough to productize and simple enough for your team to operate across dozens or hundreds of tenants.
The goal of prevention is to make it significantly harder for attackers to obtain and successfully use credentials, without creating so much friction that users bypass your controls. As an MSP, this is where you standardize identity hygiene and user education across every tenant so you are not reinventing the wheel one client at a time.
When you treat preventive controls as a standardized service, you shrink the pool of exposed credentials and reduce how often attackers ever get a valid login.
Once credentials are in play, the difference between a normal session and an ATO comes from behavior inside the account, not from the initial sign in screen. Detection for MSPs should focus on the handful of high value signals that consistently show up when an attacker takes control and begins using the account for fraud or lateral movement.
By centering detection on behavior inside the mailbox, you gain a realistic chance of catching ATOs that have already slipped past perimeter defenses.
When an ATO is suspected, your value as an MSP is measured by how quickly you can contain the account, clean up attacker activity, and restore trust without creating unnecessary chaos for the client. That requires a simple, repeatable response pattern that your team can execute the same way every time under pressure.
A disciplined, repeatable response routine turns ATOs from chaotic fire drills into manageable security events that you can confidently own on behalf of your clients.
Our ATO Protection connects to Microsoft 365 through native APIs, so you do not touch MX records or insert a gateway. You gain continuous inbox-level visibility and protection for every user across every tenant without delivery risk or mail rerouting. This provides a foundation for accurate ATO detection and services you can scale quickly.
Our ATO solution builds a baseline for each user that includes relationships, sending and receiving norms, and device and location attributes. It uses those signals to spot suspicious rules, abnormal outreach, unusual travel or client changes, and content shifts that point to takeover. Because detection is rooted in behavior and intent, it surfaces the patterns attackers rely on after they obtain credentials.
Detection alone is not enough. Our Advanced ATO clusters related incidents so one confirmed ATO can drive remediation across similar messages and accounts. You choose the level of automation, from fully autonomous actions to analyst-approved steps, while still moving faster than manual triage. In practice, that means enforced logouts, rule cleanup, and tenant-wide message remediation executed in a few clicks.
From a single multi-tenant console, you can onboard new tenants in minutes, apply standard baselines, and report on incidents and dwell time. Integrations with SIEM, SOAR, and PSA systems help you fold ATO response into existing runbooks and billing. The result is an ATO service you can bundle cleanly without operational drag.
Here are three ways to turn this capability into clear, repeatable offers.
You can deliver all three using the same platform and processes, which supports profitability without adding excessive overhead.
ATOs are now a steady reality, not a rare event. Attackers are patient, creative, and comfortable operating inside authenticated sessions where traditional tools have blind spots.
To move from compromise to control, MSPs need:
IRONSCALES Advanced ATO Protection is built around those principles and around how MSPs actually run their business. It gives you a way to reduce client risk, create differentiated services, and protect your team from the operational drag of manual ATO response.
If you adopt this playbook and pair it with the right technology, ATO becomes a manageable, predictable problem instead of a constant source of surprise.