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Account Takeover Protection

Account Takeover (ATO) Prevention

Account takeover (ATO) is one of the fastest growing threats over email as these originate from trusted sources and have low detection rates. Using behavioral intelligence modeling, powered by machine learning, Tessian detects even the most advanced ATO attacks.



The ATO Challenge


ATO threats pose significant danger to organizations as threat actors use sophisticated impersonation techniques and trusted email accounts to launch attacks that bypass conventional, rule based threat detection tools. While organizations can secure their own email infrastructure, they have no control over their extended network of customers, partners, and suppliers.


Detecting attacks from trusted accounts is extremely difficult because:
  • The malicious email is from a trusted source.
  • The emails are 100% real with legitimate headers and metadata that pass email authentication.
  • Organizations have no visibility over breaches that happen across this trusted network.

The ATO attack chain

  • 1. Credential Theft

    An attacker steals the credentials of an employee in your trusted external network using a variety of techniques such as a non-targeted phishing attack, a spear phishing email, brute force attack, password compromise, or leaked credentials online.

  • 2. Account Takeover

    Once the attacker gets hold of the account credentials, they choose a target organization in the network of the victim and start sending out emails from the compromised account. The emails usually contain a malicious link, malware, or a request for confidential information, funds transfer, or credentials.

  • 3. Breach

    People who receive these emails have no idea that their trusted network has been compromised. The emails look genuine, are from a trusted contact, and pass authentication checks performed by rule based email security solutions such as SPF, DMARC and DKIM. The victim performs the requested task, which usually results in a breach.

ATO Can Lead to Business Email Compromise


ATO is one of the pathways to Business Email Compromise (BEC), which is the biggest cause of email breaches globally.


Sometimes, the ATO attack chain does not end with an individual employee’s credentials being compromised. The attacker might use this account to access the email credentials of other employees within the same organization, especially the C-suite executives to execute a breach.



Detecting email credential theft could take months


One of the biggest challenges before CISOs is to lower their risk exposure by building a proactive security strategy that can anticipate, identify, and prevent potential ATO attempts well ahead of an actual breach.


Most legacy email security tools largely rely on static rules and previously known attack signatures to stop threats. As a result, organizations today learn about these attacks months after they have been breached and have incurred significant damages.



How Tessian Stops ATO Attacks

  • Detect Anomalous Signals

    Using machine learning powered behavioral analysis, content analysis and user identity anomaly detection, Tessian detects a range of threat signals such as anomalous geophysical location, time email is sent, IP address, email client, unusual reply-to addresses, anomalous recipients, and more. This allows Tessian to detect anomalies in even the most sophisticated attacks.



  • Spot Suspicious Payloads

    Tessian can also precisely spot any language that conveys suspicious intent using Natural Language Processing; suspicious URLs using machine learning; and suspicious attachments through content interrogation. The algorithm does all these in sub-seconds, without hindering the user experience.


  • Model Threats, Alert Users, and Remediate

    When a threat is detected, end-users receive in-the-moment alerts to help them identify and self-triage ATO emails. Tessian also offers administrators a variety of remediation options and the flexibility to determine the type of controls and alerts for end users.



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The Value of Tessian against ATO

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Learn how Tessian’s intelligent approach to email security can help your organization detect and prevent ATO attacks.