Cisco Secure Access - File Events

Overview

The Cisco Secure Access File Events log shows your organization's traffic events involving file access that match private access rules with File Inspection or File Type Control enabled.

Vendor: Cisco
Supported environment: Cloud
Detection based on: Telemetry

Warning

Important note - This format is currently in beta. We highly value your feedback to improve its performance.

Configure

This section will guide you through configuring Cisco Secure Access to forward logs to Sekoia.io using a Cisco-managed Amazon S3 bucket.

Prerequisites

Full Admin user role in Cisco Secure Access. For more information, see the Manage Accounts documentation.
Access to Sekoia.io Intakes and Playbook pages with write permissions.

Step 1 — Configure the Cisco-Managed S3 Bucket

Cisco Secure Access can export your logs to a Cisco-managed Amazon S3 bucket. Cisco configures all managed buckets to use Amazon Server-Side Encryption with S3-Managed Keys (SSE-S3, AES-256). Access is provided via AWS IAM credentials.

In the Cisco Secure Access dashboard, navigate to Admin > Log Management.
Click Set up cloud storage and select Cisco.
Select a Region — choose the region closest to you to minimize latency when downloading logs.

Warning

The selected region cannot be changed later without deleting your current settings and starting over. Not all AWS regions are available.
Select a Retention Duration — choose 7, 14, or 30 days.

Note

Beyond the selected time period, all data is purged and cannot be retrieved. A shorter duration is recommended if your ingestion cycle is frequent.
Click Save. Cisco Secure Access activates log export to the S3 bucket. When activation is complete, the Amazon S3 Summary page appears.
Copy the Access Key and Secret Key and store them in a safe place.

Warning

The Access Key and Secret Key are displayed only once. If you lose them, you must regenerate them by rotating the keys in Cisco Secure Access.
Click Done.

Step 2 — Create the Intake

Configure Your Intake

This section will guide you through creating the intake object in Sekoia, which provides a unique identifier called the "Intake key." The Intake key is essential for later configuration, as it references the Community, Entity, and Parser (Intake Format) used when receiving raw events on Sekoia.

Go to the Sekoia Intake page.
Click on the + New Intake button at the top right of the page.
Search for your Intake by the product name in the search bar.
Give it a Name and associate it with an Entity (and a Community if using multi-tenant mode).
Click on Create.

Note

For more details on how to use the Intake page and to find the Intake key you just created, refer to this documentation.

Step 3 — Configure the Connector

Configure Your Playbook

This section will assist you in pulling remote logs from Sekoia and sending them to the intake you previously created.

Go to the Sekoia playbook page.
Click on the + New playbook button at the top right of the page.
Select Create a playbook from scratch, and click Next.
Give it a Name and a Description, and click Next.
Choose a trigger from the list by searching for the name of the product, and click Create.
A new Playbook page will be displayed. Click on the module in the center of the page, then click on the Configure icon.
On the right panel, click on the Configuration tab.
Select an existing Trigger Configuration (from the account menu) or create a new one by clicking on + Create new configuration.
Configure the Trigger based on the Actions Library (for instance, see here for AWS modules), then click Save.
Click on Save at the top right of the playbook page.
Activate the playbook by clicking on the "On / Off" toggle button at the top right corner of the page.

When selecting the trigger, choose Fetch new logs on S3 (without SQS).

Before configuring the connector, retrieve the Data path from the Cisco Secure Access Amazon S3 Summary page. It looks like this:

s3://cisco-managed-eu-central-1/1234567_a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0

From this path:

the bucket name is the first segment after s3:// — here, cisco-managed-eu-central-1.
the base prefix is the second segment — here, 1234567_a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0. Cisco stores each log type in a dedicated subfolder under this prefix.

In the connector configuration, set the following fields:

AWS Region (aws_region_name): the region you selected when configuring the S3 bucket in Cisco Secure Access (for example, eu-central-1).
AWS Access Key (aws_access_key): the Access Key copied from the Cisco Secure Access Amazon S3 Summary page.
AWS Secret Access Key (aws_secret_access_key): the Secret Key copied from the Cisco Secure Access Amazon S3 Summary page.
Bucket (bucket): the bucket name extracted from the Data path (for example, cisco-managed-eu-central-1).
Prefix filter (prefix_filter): the base prefix followed by the subfolder matching the log type you want to collect. Since the bucket holds several log types, this filter ensures the connector only ingests the logs for this intake.
Intake key (intake_key): the intake key generated when you created the intake in Step 2.

Cisco Secure Access stores each log type in a dedicated subfolder under the base prefix. Set the Prefix filter to <base_prefix>/<subfolder>, using the subfolder that matches the intake you are configuring:

Intake	Subfolder	Example prefix filter
Cisco Secure Access - DNS	`dnslogs`	`1234567_a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0/dnslogs`
Cisco Secure Access - Web	`proxylogs`	`1234567_a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0/proxylogs`
Cisco Secure Access - Cloud Firewall	`firewalllogs`	`1234567_a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0/firewalllogs`
Cisco Secure Access - IPS	`intrusionlogs`	`1234567_a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0/intrusionlogs`
Cisco Secure Access - File Events	`fileeventlogs`	`1234567_a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0/fileeventlogs`

Note

Replace 1234567_a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0 with the base prefix extracted from your own Cisco Secure Access Data path.

Event Categories

The following table lists the data source offered by this integration.

Data Source	Description
`File monitoring`	None

In details, the following table denotes the type of events produced by this integration.

Name	Values
Kind	``
Category	`file`, `malware`
Type	`info`

Transformed Events Samples after Ingestion

This section demonstrates how the raw logs will be transformed by our parsers. It shows the extracted fields that will be available for use in the built-in detection rules and hunting activities in the events page. Understanding these transformations is essential for analysts to create effective detection mechanisms with custom detection rules and to leverage the full potential of the collected data.

test_file_events.json

{
    "message": "\"2024-09-04 19:43:36\",\"REDACTED\",\"730\",\"us-west-2a\",\"9c8eff3ef69147905ff1ddec8b593c94be6d17fbc916f604b7deca0ba24299ae\u00a63\u00a61725479009\u00a667\",\"CUSTOM_DETECTION\",\"UNKNOWN\",\"01ba4719c80b6fe911b091a7c05124b64eeece964e09c058ef8f9805daca546b\",\"DOWNLOAD\",\"Carbanak\",\"ANALYSIS_COMPLETE_NO_VIRUS\",\"90\",\"45\",\"TryDownloading_9974801.sample\",\"52224\",\"TryDownloading_9974801.zip\",\"1\",\"01ba4719c80b6fe911b091a7c05124b64eeece964e09c058ef8f9805daca546b\",\"FW_FILE_DLP_NONE\",\"FTD\",\"12321321312\",\"\"",
    "event": {
        "action": "custom_detection",
        "category": [
            "file",
            "malware"
        ],
        "dataset": "file-events",
        "outcome": [
            "unknown"
        ],
        "type": [
            "info"
        ]
    },
    "@timestamp": "2024-09-04T19:43:36Z",
    "cisco_secure_access": {
        "file": {
            "archive_depth": 1,
            "archive_filename": "TryDownloading_9974801.zip",
            "archive_sha256": "01ba4719c80b6fe911b091a7c05124b64eeece964e09c058ef8f9805daca546b",
            "direction": "DOWNLOAD",
            "disposition": "UNKNOWN",
            "dlp_status": "FW_FILE_DLP_NONE",
            "enforced_by": "FTD",
            "firewall_event_id": "9c8eff3ef69147905ff1ddec8b593c94be6d17fbc916f604b7deca0ba24299ae\u00a63\u00a61725479009\u00a667",
            "ftd_enforcement_id": "12321321312",
            "retention_policy_days": 730,
            "static_analysis": "ANALYSIS_COMPLETE_NO_VIRUS",
            "threat_score": 90,
            "type_id": 45
        }
    },
    "cloud": {
        "region": "us-west-2a"
    },
    "file": {
        "hash": {
            "sha256": "01ba4719c80b6fe911b091a7c05124b64eeece964e09c058ef8f9805daca546b"
        },
        "name": "TryDownloading_9974801.sample",
        "size": 52224
    },
    "observer": {
        "product": "Secure Access",
        "type": "proxy",
        "vendor": "Cisco"
    },
    "organization": {
        "id": "REDACTED"
    },
    "related": {
        "hash": [
            "01ba4719c80b6fe911b091a7c05124b64eeece964e09c058ef8f9805daca546b"
        ]
    },
    "threat": {
        "indicator": {
            "name": "Carbanak"
        }
    }
}

Extracted Fields

The following table lists the fields that are extracted, normalized under the ECS format, analyzed and indexed by the parser. It should be noted that infered fields are not listed.

Name	Type	Description
`@timestamp`	`date`	Date/time when the event originated.
`cisco_secure_access.file.archive_depth`	`long`	The level (if any) at which the file was nested in an archive file.
`cisco_secure_access.file.archive_filename`	`keyword`	The name of the archive file involved with the activity.
`cisco_secure_access.file.archive_sha256`	`keyword`	The SHA-256 checksum hash of the archive file.
`cisco_secure_access.file.direction`	`keyword`	The traffic direction of the file event.
`cisco_secure_access.file.disposition`	`keyword`	The status of the files proxied and scanned by Cisco Advanced Malware Protection (AMP) as part of the File Inspection feature.
`cisco_secure_access.file.dlp_status`	`keyword`	The verdict of the DLP scanning service.
`cisco_secure_access.file.enforced_by`	`keyword`	The Secure Access component or service that enforced the policy or control related to this event (e.g., Firewall, Web Proxy).
`cisco_secure_access.file.firewall_event_id`	`keyword`	The ID of the firewall event. Populated only for traffic handled by Cisco Secure Firewall.
`cisco_secure_access.file.ftd_enforcement_id`	`keyword`	The unique identifier of the enforcement action taken by a Firepower Threat Defense (FTD) device integrated with Secure Access.
`cisco_secure_access.file.ftd_enforcement_name`	`keyword`	The name or type of enforcement action taken by a FTD device integrated with Secure Access (e.g., Malware Block, URL Category Block).
`cisco_secure_access.file.retention_policy_days`	`long`	The number of days that AWS S3 stores your Secure Access File Events log.
`cisco_secure_access.file.static_analysis`	`keyword`	The status of the file static sample analysis.
`cisco_secure_access.file.threat_score`	`long`	The threat score most recently associated with this file. This is a value from 0 to 100.
`cisco_secure_access.file.type_id`	`long`	The type of file.
`cloud.region`	`keyword`	Region in which this host, resource, or service is located.
`event.action`	`keyword`	The action captured by the event.
`event.category`	`keyword`	Event category. The second categorization field in the hierarchy.
`event.dataset`	`keyword`	Name of the dataset.
`event.type`	`keyword`	Event type. The third categorization field in the hierarchy.
`file.hash.sha256`	`keyword`	SHA256 hash.
`file.name`	`keyword`	Name of the file including the extension, without the directory.
`file.size`	`long`	File size in bytes.
`observer.product`	`keyword`	The product name of the observer.
`observer.type`	`keyword`	The type of the observer the data is coming from.
`observer.vendor`	`keyword`	Vendor name of the observer.
`organization.id`	`keyword`	Unique identifier for the organization.

For more information on the Intake Format, please find the code of the Parser, Smart Descriptions, and Supported Events here.

Detection section

The following section provides information for those who wish to learn more about the detection capabilities enabled by collecting this intake. It includes details about the built-in rule catalog, event categories, and ECS fields extracted from raw events. This is essential for users aiming to create custom detection rules, perform hunting activities, or pivot in the events page.

The following Sekoia.io built-in rules match the intake Cisco Secure Access - File Events. This documentation is updated automatically and is based solely on the fields used by the intake which are checked against our rules. This means that some rules will be listed but might not be relevant with the intake.

SEKOIA.IO x Cisco Secure Access - File Events on ATT&CK Navigator

Advanced IP Scanner

Detects the use of Advanced IP Scanner. Seems to be a popular tool for ransomware groups.

Effort: master

Certify Or Certipy

Detects the use of certify and certipy which are two different tools used to enumerate and abuse Active Directory Certificate Services.

Effort: advanced

Cobalt Strike Default Beacons Names

Detects the default names of Cobalt Strike beacons / payloads.

Effort: intermediate

Credential Dump Tools Related Files

Detects processes or file names related to credential dumping tools and the dropped files they generate by default.

Effort: advanced

HackTools Suspicious Names

Quick-win rule to detect the default process names or file names of several HackTools.

Effort: advanced

PasswordDump SecurityXploded Tool

Detects the execution of the PasswordDump SecurityXploded Tool

Effort: elementary

RTLO Character

Detects RTLO (Right-To-Left character) in file and process names.

Effort: elementary

Sekoia.io Activity Logs Rule Deactivation Bulk

Detects a massive rule deactivation observed threw Sekoia.io activity logs.

Effort: master

Suspicious PROCEXP152.sys File Created In Tmp

Detects the creation of the PROCEXP152.sys file in the application-data local temporary folder. This driver is used by Sysinternals Process Explorer but also by KDU (https://github.com/hfiref0x/KDU) or Ghost-In-The-Logs (https://github.com/bats3c/Ghost-In-The-Logs), which uses KDU. Note - Clever attackers may easily bypass this detection by just renaming the driver filename. Therefore just Medium-level and don't rely on it.

Effort: advanced

WCE wceaux.dll Creation

Detects wceaux.dll creation while Windows Credentials Editor (WCE) is executed.

Effort: intermediate