Collect Mimecast Mail V2 logs

Supported in:

Google secops SIEM

Note: This feature is covered by Pre-GA Offerings Terms of the Google Security Operations Service Specific Terms. Pre-GA features might have limited support, and changes to pre-GA features might not be compatible with other pre-GA versions. For more information, see the Google SecOps Technical Support Service guidelines and the Google SecOps Service Specific Terms.

This document explains how to collect Mimecast Mail V2 logs by setting up a Google Security Operations feed using the Third party API.

Before you begin

Ensure that you have the following prerequisites:

• A Google SecOps instance
• Privileged access to Mimecast Mail V2 tenant or admin console
• Admin privileges in Mimecast to create API applications

Caution: You must enable allowlisting and add the IP ranges for all log types that ingest data from third-party APIs. For more information, see IP Allowlisting.

Configure IP allowlisting

Before creating the feed, you must allowlist Google SecOps IP ranges in your Mimecast Mail V2 firewall or network settings.

Get Google SecOps IP ranges

• Fetch IP ranges from the Google IP address ranges JSON file.

Add IP ranges to Mimecast Mail V2

1. Sign in to the Mimecast Administration Console.
2. Go to Administration > Services > Firewall Policies.
3. Click Add Address.
4. Enter each Google SecOps IP range in CIDR notation.
5. Select Allow for the Action.
6. Provide a description (for example, Google SecOps Integration).
7. Click Save.

Configure Mimecast Mail V2 API access

To enable Google SecOps to pull logs from Mimecast, you need to register an application in the Mimecast Administration Console and obtain OAuth credentials.

Create API application

1. Sign in to the Mimecast Administration Console.
2. Go to Administration > Services > API Management > Applications.
3. Click Add.
4. Provide the following configuration details:
   • Name: Enter a descriptive name (for example, Google SecOps Integration).
   • Description (optional): Enter a description.
   • Type: Select OAuth.
   • OAuth Grant Type: Select Client Credentials.
   • URL: Enter your Google SecOps domain or leave blank.
5. Under Access Scopes, select the required permissions (see Required API Permissions section).
6. Click Save.

Generate API credentials

1. After creating the application, click the application name in the list.
2. Go to the OAuth tab.
3. Click Create Credentials.
4. Note the Client ID and Client Secret displayed.
5. Click Close.

Record API credentials

After generating the credentials, you'll receive the following:

• Client ID: Your OAuth 2.0 client identifier
• Client Secret: Your OAuth 2.0 client secret

Important: Copy and save these credentials securely. You'll need them to configure the Google SecOps feed.

Required API permissions

The API application requires the following permissions:

Permission/Scope	Access Level	Purpose
Audit/SIEM	Read	Retrieve SIEM log data
Audit/AuditEvents	Read	Retrieve audit event data

Note: Using least-privilege access. Only read permissions are required; write permissions are not needed for log ingestion.

Set up feeds

To configure a feed, follow these steps:

1. Go to SIEM Settings > Feeds.
2. Click Add New Feed.
3. On the next page, click Configure a single feed.
4. In the Feed name field, enter a name for the feed (for example, Mimecast Mail Logs).
5. Select Third party API as the Source type.
6. Select Mimecast Mail V2 as the Log type.
7. Click Next.

8. Specify values for the following input parameters:

   • OAuth client ID: The client ID from the API application created earlier.
   • OAuth client secret: The client secret from the API application created earlier.
   • Asset namespace: The asset namespace.
   • Ingestion labels: The label to be applied to the events from this feed.

9. Click Next.

10. Review your new feed configuration in the Finalize screen, and then click Submit.

After setup, the feed begins to retrieve logs from the Mimecast Mail V2 instance in chronological order.

Regional endpoints

Mimecast Mail V2 uses different API endpoints based on your region:

Region	Base URL
US	https://us-api.mimecast.com
UK	https://uk-api.mimecast.com
EU	https://eu-api.mimecast.com
DE	https://de-api.mimecast.com
AU	https://au-api.mimecast.com
ZA	https://za-api.mimecast.com
CA	https://ca-api.mimecast.com
Offshore	https://je-api.mimecast.com

Use the base URL that corresponds to your Mimecast Mail V2 instance region.

UDM mapping table

Log Field	UDM Mapping	Logic
aCode	additional_fields.aCode	Value taken from aCode.
Att_AV	additional_fields.Att_AV	Value taken from Att_AV.
Att_Det	additional_fields.Att_Det	Value taken from Att_Det.
Att_Enc	additional_fields.Att_Enc	Value taken from Att_Enc.
Att_Key	additional_fields.Att_Key	Value taken from Att_Key.
Att_Mod	additional_fields.Att_Mod	Value taken from Att_Mod.
Att_Orig	additional_fields.Att_Orig	Value taken from Att_Orig.
Att_Rem	additional_fields.Att_Rem	Value taken from Att_Rem.
Att_State	additional_fields.Att_State	Value taken from Att_State.
Att_Type	additional_fields.Att_Type	Value taken from Att_Type.
CKS	additional_fields.CKS	Value taken from CKS.
Date	additional_fields.Date	Value taken from Date.
Delivered	additional_fields.Delivered	Value taken from Delivered.
dlp	additional_fields.dlp	Value taken from dlp.
Dmarc	additional_fields.Dmarc	Value taken from Dmarc.
Enc	additional_fields.Enc	Value taken from Enc.
Error_Code	additional_fields.Error_Code	Value taken from Error_Code.
Error_Type	additional_fields.Error_Type	Value taken from Error_Type.
Grey	additional_fields.Grey	Value taken from Grey.
header_id	additional_fields.header_id	Value taken from header_id.
Hold_For	additional_fields.Hold_For	Value taken from Hold_For.
Hold_Reason	additional_fields.Hold_Reason	Value taken from Hold_Reason.
Latency	additional_fields.Latency	Value taken from Latency.
Malware_Hash	additional_fields.Malware_Hash	Value taken from Malware_Hash.
Malware_Name	additional_fields.Malware_Name	Value taken from Malware_Name.
Msg_Key	additional_fields.Msg_Key	Value taken from Msg_Key.
MsgSize	additional_fields.MsgSize	Value taken from MsgSize.
Policy	additional_fields.Policy	Value taken from Policy.
Processing_Time	additional_fields.Processing_Time	Value taken from Processing_Time.
Queue_ID	additional_fields.Queue_ID	Value taken from Queue_ID.
rcpt_type	additional_fields.rcpt_type	Value taken from rcpt_type.
Receipt	additional_fields.Receipt	Value taken from Receipt.
sCode	additional_fields.sCode	Value taken from sCode.
Sent	additional_fields.Sent	Value taken from Sent.
Snt	additional_fields.Snt	Value taken from Snt.
spamLimit	additional_fields.spamLimit	Value taken from spamLimit.
spamScore	additional_fields.spamScore	Value taken from spamScore.
SpamRef	additional_fields.SpamRef	Value taken from SpamRef.
Tarpit	additional_fields.Tarpit	Value taken from Tarpit.
Time	additional_fields.Time	Value taken from Time.
datetime	metadata.event_timestamp	Value taken from datetime. The original datetime field is also parsed to set the event's primary @timestamp.
	metadata.event_type	Set to NETWORK_EMAIL.
	metadata.product_event_type	Set to processed_email.
dir	network.direction	Derived from dir: In -> INBOUND; Out -> OUTBOUND; Int -> UNKNOWN.
sender, route, hdr_from	network.email.from	Value taken from sender, then route. If still empty, value is taken from hdr_from.
MsgID	network.email.message_id	Value taken from MsgID.
subject	network.email.subject	Value taken from subject.
rcpt	network.email.to	Value taken from rcpt and split by ',' into an array.
IP	principal.ip	Value taken from IP and split by ',' into an array.
hdr_from	principal.user.email_addresses	Value taken from hdr_from and split by ',' into an array.
act	security_result.action	Derived from act: Rej, T, Hld, Bnc -> BLOCK; U, A -> ALLOW; else UNKNOWN.
Att_Hash	target.file.md5	Value taken from Att_Hash.
Att_Name	target.file.name	Value taken from Att_Name.
Att_Size	target.file.size	Value taken from Att_Size and converted to integer.
URL	target.url	Value taken from URL.
rcpt_to	target.user.email_addresses	Value taken from rcpt_to and split by ',' into an array.
	metadata.product_name	Set to Mail V2.
	metadata.vendor_name	Set to Mimecast.

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