Email Collection: Remote Email Collection T1114.002
Tactic: Collection
Adversaries may target an Exchange server, Office 365, or Google Workspace to collect sensitive information. Adversaries may leverage a user's credentials and interact directly with the Exchange server to acquire information from within a network. Adversaries may also access externally facing Exchange services, Office 365, or Google Workspace to access email using credentials or access tokens. Tools such as MailSniper can be used to automate searches for specific keywords.
Events covered
4 catalog events are tagged with this technique by at least one rule.
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 1 | Process creation |
| Security-Auditing | Event ID 4688 | A new process has been created. |
| PowerShell | Event ID 4103 | Payload Context: ContextInfo User Data: UserData. |
| PowerShell | Event ID 4104 | Creating Scriptblock text (MessageNumber of MessageTotal). |
Authoring guide
Patterns shared across the 19 rules above: which fields they filter on, what specific values they look for, and what they exclude. The catalog normalizes field names across vendors so Sigma's Image, Elastic's process.name, and Splunk's process_name collapse into one row. Each rule contributes at most once per row.
Fields filtered most (45 distinct)
The fields most rules look at when detecting this technique. The How column shows the operators authors use (eq, wildcard, regex_match, match) and how often each appears. Sample values are concrete examples to start from, not an exhaustive list.
Top indicator values (100 distinct)
Specific (field, operator, value) combinations the rules check for, ranked by how many rules under this technique use each one. The Corpus reach column counts how many rules across the entire catalog (any technique) check the same combination. High numbers point to widely-used indicators that are likely noisy on their own; combine them with another condition for useful signal. Blank means the combination is specific to rules under this technique. Click a value to expand the rules under this technique that use it.
Exclusions (146 distinct)
Field/operator/value combinations excluded by rules under this technique (top-level not() clauses), sorted by how many rules exclude each. These are the false-positive paths the community has learned to filter out. A new rule that ignores the high-count entries here will likely fire on the same noisy paths. Click a value to expand the rules under this technique that exclude it.
Rules under this technique
Every rule in the catalog tagged with this technique, grouped by vendor. Click a rule title for its full predicates, exclusions, and indicators.
Elastic 7 rules
- Exchange Mailbox Export via PowerShell
- Exporting Exchange Mailbox via PowerShell
- M365 Exchange Mailbox Accessed by Unusual Client
- M365 Exchange Mailbox Items Accessed Excessively
- Microsoft Graph Request Email Access by Unusual User and Client
- New ActiveSyncAllowedDeviceID Added via PowerShell
- PowerShell Mailbox Collection Script
Splunk 12 rules
- Email servers sending high volume traffic to hosts
- Exchange New Export Request (PowerShell)
- Hosts receiving high volume of network traffic from email server
- O365 Compliance Content Search Exported
- O365 Compliance Content Search Started
- O365 Email Access By Security Administrator
- O365 Email Suspicious Search Behavior
- O365 Mailbox Inbox Folder Shared with All Users
- O365 Mailbox Read Access Granted to Application
- O365 Multiple Mailboxes Accessed via API
- O365 OAuth App Mailbox Access via EWS
- O365 OAuth App Mailbox Access via Graph API