Email Collection T1114

Events covered

8 catalog events are tagged with this technique by at least one rule.

Authoring guide

Patterns shared across the 69 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 (119 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 (301 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 (161 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.

Sigma 11 rules

• Exchange PowerShell Snap-Ins Usage
• Google Workspace Out Of Domain Email Forwarding
• Hacktool Ruler
• Inbox Rules Creation Or Update Activity in O365
• Inbox Rules Creation Or Update Activity Via ExchangePowerShell Cmdlet
• Mail Forwarding/Redirecting Activity In O365
• Mail Forwarding/Redirecting Activity Via ExchangePowerShell Cmdlet
• Powershell Local Email Collection
• PST Export Alert Using eDiscovery Alert
• PST Export Alert Using New-ComplianceSearchAction
• Suspicious Inbox Forwarding Identity Protection

Elastic 13 rules

• Accessing Outlook Data Files
• Exchange Mailbox Export via PowerShell
• Exporting Exchange Mailbox via PowerShell
• Google Workspace Custom Gmail Route Created or Modified
• M365 Exchange Inbox Forwarding Rule Created
• M365 Exchange Mail Flow Transport Rule Created
• M365 Exchange Mailbox Accessed by Unusual Client
• M365 Exchange Mailbox Items Accessed Excessively
• M365 Purview DLP Signal
• Microsoft Graph Request Email Access by Unusual User and Client
• New ActiveSyncAllowedDeviceID Added via PowerShell
• PowerShell Mailbox Collection Script
• Suspicious Inter-Process Communication via Outlook

Splunk 26 rules

• Email files written outside of the Outlook directory
• Email servers sending high volume traffic to hosts
• Exchange New Export Request (PowerShell)
• Hosts receiving high volume of network traffic from email server
• Mailsniper Invoke functions
• O365 Compliance Content Search Exported
• O365 Compliance Content Search Started
• O365 Email Access By Security Administrator
• O365 Email New Inbox Rule Created
• O365 Email Password and Payroll Compromise Behavior
• O365 Email Receive and Hard Delete Takeover Behavior
• O365 Email Send and Hard Delete Exfiltration Behavior
• O365 Email Send and Hard Delete Suspicious Behavior
• O365 Email Suspicious Behavior Alert
• O365 Email Suspicious Search Behavior
• O365 Email Transport Rule Changed
• O365 Mailbox Email Forwarding Enabled
• O365 Mailbox Inbox Folder Shared with All Users
• O365 Mailbox Read Access Granted to Application
• O365 Multiple Mailboxes Accessed via API
• O365 New Email Forwarding Rule Created
• O365 New Email Forwarding Rule Enabled
• O365 New Forwarding Mailflow Rule Created
• O365 OAuth App Mailbox Access via EWS
• O365 OAuth App Mailbox Access via Graph API
• O365 PST export alert

Kusto 16 rules

• Exchange workflow MailItemsAccessed operation anomaly
• GWorkspace - An Outbound Relay has been added to a G Suite Domain
• High risk Office operation conducted by IP Address that recently attempted to log into a disabled account
• Mail redirect via ExO transport rule
• Mimecast Secure Email Gateway - Attachment Protect
• Mimecast Secure Email Gateway - Attachment Protect
• Mimecast Secure Email Gateway - Impersonation Protect
• Mimecast Secure Email Gateway - Impersonation Protect
• Mimecast Targeted Threat Protection - Impersonation Protect
• Multiple users email forwarded to same destination
• NRT Multiple users email forwarded to same destination
• Powershell Empire Cmdlets Executed in Command Line
• Rare and potentially high-risk Office operations
• Server Oriented Cmdlet And User Oriented Cmdlet used
• Threat Essentials - Mail redirect via ExO transport rule
• VIP Mailbox manipulation

Panther 3 rules

• AppOmni Alert Passthrough
• Gsuite Mail forwarded to external domain
• Microsoft Exchange External Forwarding