T1114 - Email Collection

Adversaries may target user email to collect sensitive information. Emails may contain sensitive data, including trade secrets or personal information, that can prove valuable to adversaries. Adversaries can collect or forward email from mail servers or clients.

Atomic Tests:

Currently, no tests are available for this technique.

Detection

There are likely a variety of ways an adversary could collect email from a target, each with a different mechanism for detection.

File access of local system email files for Exfiltration, unusual processes connecting to an email server within a network, or unusual access patterns or authentication attempts on a public-facing webmail server may all be indicators of malicious activity.

Monitor processes and command-line arguments for actions that could be taken to gather local email files. Remote access tools with built-in features may interact directly with the Windows API to gather information. Information may also be acquired through Windows system management tools such as Windows Management Instrumentation and PowerShell.

Detection is challenging because all messages forwarded because of an auto-forwarding rule have the same presentation as a manually forwarded message. It is also possible for the user to not be aware of the addition of such an auto-forwarding rule and not suspect that their account has been compromised; email-forwarding rules alone will not affect the normal usage patterns or operations of the email account.

Auto-forwarded messages generally contain specific detectable artifacts that may be present in the header; such artifacts would be platform-specific. Examples include X-MS-Exchange-Organization-AutoForwarded set to true, X-MailFwdBy and X-Forwarded-To. The forwardingSMTPAddress parameter used in a forwarding process that is managed by administrators and not by user actions. All messages for the mailbox are forwarded to the specified SMTP address. However, unlike typical client-side rules, the message does not appear as forwarded in the mailbox; it appears as if it were sent directly to the specified destination mailbox.(Citation: Microsoft Tim McMichael Exchange Mail Forwarding 2) High volumes of emails that bear the X-MS-Exchange-Organization-AutoForwarded header (indicating auto-forwarding) without a corresponding number of emails that match the appearance of a forwarded message may indicate that further investigation is needed at the administrator level rather than user-level.

Shield Active Defense

Decoy Content

Seed content that can be used to lead an adversary in a specific direction, entice a behavior, etc.

Decoy Content is the data used to tell a story to an adversary. This content can be legitimate or synthetic data which is used to reinforce or validate your defensive strategy. Examples of decoy content are files on a storage object, entries in the system registry, system shortcuts, etc.

Opportunity

There is an opportunity to influence an adversary to move toward systems you want them to engage with.

Use Case

A defender can plant decoy emails containing deceptive content and breadcrumbs to lure the attacker toward deception systems.

Procedures

Create directories and files with names and contents using key words that may be relevant to an adversary to see if they examine or exfiltrate the data. Seed a file system with content that is of no value to the company but reinforces the legitimacy of the system if viewed by an adversary.