CloudTrail log file examples - AWS CloudTrail
CloudTrail log file name formatLog file examples

CloudTrail log file examples

CloudTrail monitors events for your account. If you create a trail, it delivers those events as log files to your Amazon S3 bucket. If you create an event data store in CloudTrail Lake, events are logged to your event data store. Event data stores do not use S3 buckets.

CloudTrail log file name format

CloudTrail uses the following file name format for the log file objects that it delivers to your Amazon S3 bucket:

AccountID_CloudTrail_RegionName_YYYYMMDDTHHmmZ_UniqueString.FileNameFormat

  • The YYYY, MM, DD, HH, and mm are the digits of the year, month, day, hour, and minute when the log file was delivered. Hours are in 24-hour format. The Z indicates that the time is in UTC.

    Note

    A log file delivered at a specific time can contain records written at any point before that time.

  • The 16-character UniqueString component of the log file name is there to prevent overwriting of files. It has no meaning, and log processing software should ignore it.

  • FileNameFormat is the encoding of the file. Currently, this is json.gz, which is a JSON text file in compressed gzip format.

Example CloudTrail Log File Name

111122223333_CloudTrail_us-east-2_20150801T0210Z_Mu0KsOhtH1ar15ZZ.json.gz

Log file examples

A log file contains one or more records. The following examples are snippets of logs that show the records for an action that started the creation of a log file.

For information about CloudTrail event record fields, see CloudTrail record contents.

Amazon EC2 log examples

Amazon Elastic Compute Cloud (Amazon EC2) provides resizeable computing capacity in the AWS Cloud. You can launch virtual servers, configure security and networking, and manage storage. Amazon EC2 can also scale up or down quickly to handle changes in requirements or spikes in popularity, thereby reducing your need to forecast server traffic. For more information, see the Amazon EC2 User Guide.

The following example shows that an IAM user named Mateo ran the aws ec2 start-instances command to call the Amazon EC2 StartInstances action for instances i-EXAMPLE56126103cb and i-EXAMPLEaff4840c22. 

{"Records": [{
    "eventVersion": "1.08",
    "userIdentity": {
        "type": "IAMUser",
        "principalId": "EXAMPLE6E4XEGITWATV6R",
        "arn": "arn:aws:iam::123456789012:user/Mateo",
        "accountId": "123456789012",
        "accessKeyId": "AKIAIOSFODNN7EXAMPLE",
        "userName": "Mateo",
        "sessionContext": {
            "sessionIssuer": {},
            "webIdFederationData": {},
            "attributes": {
                "creationDate": "2023-07-19T21:11:57Z",
                "mfaAuthenticated": "false"
            }
        }
    },
    "eventTime": "2023-07-19T21:17:28Z",
    "eventSource": "ec2.amazonaws.com",
    "eventName": "StartInstances",
    "awsRegion": "us-east-1",
    "sourceIPAddress": "192.0.2.0",
    "userAgent": "aws-cli/2.13.5 Python/3.11.4 Linux/4.14.255-314-253.539.amzn2.x86_64 exec-env/CloudShell exe/x86_64.amzn.2 prompt/off command/ec2.start-instances",
    "requestParameters": {
        "instancesSet": {
            "items": [
                {
                    "instanceId": "i-EXAMPLE56126103cb"
                },
                {
                    "instanceId": "i-EXAMPLEaff4840c22"
                }
            ]
        }
    },
    "responseElements": {
        "requestId": "e4336db0-149f-4a6b-844d-EXAMPLEb9d16",
        "instancesSet": {
            "items": [
                {
                    "instanceId": "i-EXAMPLEaff4840c22",
                    "currentState": {
                        "code": 0,
                        "name": "pending"
                    },
                    "previousState": {
                        "code": 80,
                        "name": "stopped"
                    }
                },
                {
                    "instanceId": "i-EXAMPLE56126103cb",
                    "currentState": {
                        "code": 0,
                        "name": "pending"
                    },
                    "previousState": {
                        "code": 80,
                        "name": "stopped"
                    }
                }
            ]
        }
    },
    "requestID": "e4336db0-149f-4a6b-844d-EXAMPLEb9d16",
    "eventID": "e755e09c-42f9-4c5c-9064-EXAMPLE228c7",
    "readOnly": false,
    "eventType": "AwsApiCall",
    "managementEvent": true,
    "recipientAccountId": "123456789012",
    "eventCategory": "Management",
     "tlsDetails": {
        "tlsVersion": "TLSv1.2",
        "cipherSuite": "ECDHE-RSA-AES128-GCM-SHA256",
        "clientProvidedHostHeader": "ec2.us-east-1.amazonaws.com"
    },
    "sessionCredentialFromConsole": "true"
}]}

The following example shows that an IAM user named Nikki ran the aws ec2 stop-instances command to call the Amazon EC2 StopInstances action to stop two instances.

{"Records": [{
    "eventVersion": "1.08",
    "userIdentity": {
        "type": "IAMUser",
        "principalId": "EXAMPLE6E4XEGITWATV6R",
        "arn": "arn:aws:iam::777788889999:user/Nikki",
        "accountId": "777788889999",
        "accessKeyId": "AKIAI44QH8DHBEXAMPLE",
        "userName": "Nikki",
        "sessionContext": {
            "sessionIssuer": {},
            "webIdFederationData": {},
            "attributes": {
                "creationDate": "2023-07-19T21:11:57Z",
                "mfaAuthenticated": "false"
            }
        }
    },
    "eventTime": "2023-07-19T21:14:20Z",
    "eventSource": "ec2.amazonaws.com",
    "eventName": "StopInstances",
    "awsRegion": "us-east-1",
    "sourceIPAddress": "192.0.2.0",
    "userAgent": "aws-cli/2.13.5 Python/3.11.4 Linux/4.14.255-314-253.539.amzn2.x86_64 exec-env/CloudShell exe/x86_64.amzn.2 prompt/off command/ec2.stop-instances",
    "requestParameters": {
        "instancesSet": {
            "items": [
                {
                    "instanceId": "i-EXAMPLE56126103cb"
                },
                {
                    "instanceId": "i-EXAMPLEaff4840c22"
                }
            ]
        },
        "force": false
    },
    "responseElements": {
        "requestId": "c308a950-e43e-444e-afc1-EXAMPLE73e49",
        "instancesSet": {
            "items": [
                {
                    "instanceId": "i-EXAMPLE56126103cb",
                    "currentState": {
                        "code": 64,
                        "name": "stopping"
                    },
                    "previousState": {
                        "code": 16,
                        "name": "running"
                    }
                },
                {
                    "instanceId": "i-EXAMPLEaff4840c22",
                    "currentState": {
                        "code": 64,
                        "name": "stopping"
                    },
                    "previousState": {
                        "code": 16,
                        "name": "running"
                    }
                }
            ]
        }
    },
    "requestID": "c308a950-e43e-444e-afc1-EXAMPLE73e49",
    "eventID": "9357a8cc-a0eb-46a1-b67e-EXAMPLE19b14",
    "readOnly": false,
    "eventType": "AwsApiCall",
    "managementEvent": true,
    "recipientAccountId": "777788889999",
    "eventCategory": "Management",
     "tlsDetails": {
        "tlsVersion": "TLSv1.2",
        "cipherSuite": "ECDHE-RSA-AES128-GCM-SHA256",
        "clientProvidedHostHeader": "ec2.us-east-1.amazonaws.com"
    },
    "sessionCredentialFromConsole": "true"
}]}

The following example shows that an IAM user named Arnav ran the aws ec2 create-key-pair command to call the CreateKeyPair action. Note that the responseElements contain a hash of the key pair and that AWS removed the key material.

{"Records": [{
    "eventVersion": "1.08",
    "userIdentity": {
        "type": "IAMUser",
        "principalId": "AIDA6ON6E4XEGIEXAMPLE",
        "arn": "arn:aws:iam::444455556666:user/Arnav",
        "accountId": "444455556666",
        "accessKeyId": "AKIAI44QH8DHBEXAMPLE",
        "userName": "Arnav",
        "sessionContext": {
            "sessionIssuer": {},
            "webIdFederationData": {},
            "attributes": {
                "creationDate": "2023-07-19T21:11:57Z",
                "mfaAuthenticated": "false"
            }
        }
    },
    "eventTime": "2023-07-19T21:19:22Z",
    "eventSource": "ec2.amazonaws.com",
    "eventName": "CreateKeyPair",
    "awsRegion": "us-east-1",
    "sourceIPAddress": "192.0.2.0",
    "userAgent": "aws-cli/2.13.5 Python/3.11.4 Linux/4.14.255-314-253.539.amzn2.x86_64 exec-env/CloudShell exe/x86_64.amzn.2 prompt/off command/ec2.create-key-pair",
    "requestParameters": {
        "keyName": "my-key",
        "keyType": "rsa",
        "keyFormat": "pem"
    },
    "responseElements": {
        "requestId": "9aa4938f-720f-4f4b-9637-EXAMPLE9a196",
        "keyName": "my-key",
        "keyFingerprint": "1f:51:ae:28:bf:89:e9:d8:1f:25:5d:37:2d:7d:b8:ca:9f:f5:f1:6f",
        "keyPairId": "key-abcd12345eEXAMPLE",
        "keyMaterial": "<sensitiveDataRemoved>"
    },
    "requestID": "9aa4938f-720f-4f4b-9637-EXAMPLE9a196",
    "eventID": "2ae450ff-e72b-4de1-87b0-EXAMPLE5227cb",
    "readOnly": false,
    "eventType": "AwsApiCall",
    "managementEvent": true,
    "recipientAccountId": "444455556666",
    "eventCategory": "Management",
    "tlsDetails": {
        "tlsVersion": "TLSv1.2",
        "cipherSuite": "ECDHE-RSA-AES128-GCM-SHA256",
        "clientProvidedHostHeader": "ec2.us-east-1.amazonaws.com"
    },
    "sessionCredentialFromConsole": "true"
}]}

IAM log examples

AWS Identity and Access Management (IAM) is a web service that helps you securely control access to AWS resources. With IAM, you can centrally manage permissions that control which AWS resources users can access. You use IAM to control who is authenticated (signed in) and authorized (has permissions) to use resources. For more information, see the IAM User Guide.

The following example shows that the IAM user named Mary ran the aws iam create-user command to call the CreateUser action to create a new user named Richard.

{"Records": [{
    "eventVersion": "1.08",
    "userIdentity": {
        "type": "IAMUser",
        "principalId": "AIDA6ON6E4XEGITEXAMPLE",
        "arn": "arn:aws:iam::888888888888:user/Mary",
        "accountId": "888888888888",
        "accessKeyId": "AKIAIOSFODNN7EXAMPLE",
        "userName": "Mary",
        "sessionContext": {
            "sessionIssuer": {},
            "webIdFederationData": {},
            "attributes": {
                "creationDate": "2023-07-19T21:11:57Z",
                "mfaAuthenticated": "false"
            }
        }
    },
    "eventTime": "2023-07-19T21:25:09Z",
    "eventSource": "iam.amazonaws.com",
    "eventName": "CreateUser",
    "awsRegion": "us-east-1",
    "sourceIPAddress": "192.0.2.0",
    "userAgent": "aws-cli/2.13.5 Python/3.11.4 Linux/4.14.255-314-253.539.amzn2.x86_64 exec-env/CloudShell exe/x86_64.amzn.2 prompt/off command/iam.create-user",
    "requestParameters": {
        "userName": "Richard"
    },
    "responseElements": {
        "user": {
            "path": "/",
            "arn": "arn:aws:iam::888888888888:user/Richard",
            "userId": "AIDA6ON6E4XEP7EXAMPLE",
            "createDate": "Jul 19, 2023 9:25:09 PM",
            "userName": "Richard"
        }
    },
    "requestID": "2d528c76-329e-410b-9516-EXAMPLE565dc",
    "eventID": "ba0801a1-87ec-4d26-be87-EXAMPLE75bbb",
    "readOnly": false,
    "eventType": "AwsApiCall",
    "managementEvent": true,
    "recipientAccountId": "888888888888",
    "eventCategory": "Management",
    "tlsDetails": {
        "tlsVersion": "TLSv1.2",
        "cipherSuite": "ECDHE-RSA-AES128-GCM-SHA256",
        "clientProvidedHostHeader": "iam.amazonaws.com"
    },
    "sessionCredentialFromConsole": "true"
}]}

The following example shows that the IAM user named Paulo ran the aws iam add-user-to-group command to call the AddUserToGroup action to add a user named Jane to the Admin group.

{"Records": [{
    "eventVersion": "1.08",
    "userIdentity": {
        "type": "IAMUser",
        "principalId": "AIDA6ON6E4XEGIEXAMPLE",
        "arn": "arn:aws:iam::555555555555:user/Paulo",
        "accountId": "555555555555",
        "accessKeyId": "AKIAIOSFODNN7EXAMPLE",
        "userName": "Paulo",
        "sessionContext": {
            "sessionIssuer": {},
            "webIdFederationData": {},
            "attributes": {
                "creationDate": "2023-07-19T21:11:57Z",
                "mfaAuthenticated": "false"
            }
        }
    },
    "eventTime": "2023-07-19T21:25:09Z",
    "eventSource": "iam.amazonaws.com",
    "eventName": "AddUserToGroup",
    "awsRegion": "us-east-1",
    "sourceIPAddress": "192.0.2.0",
    "userAgent": "aws-cli/2.13.5 Python/3.11.4 Linux/4.14.255-314-253.539.amzn2.x86_64 exec-env/CloudShell exe/x86_64.amzn.2 prompt/off command/iam.add-user-to-group",
    "requestParameters": {
        "groupName": "Admin",
        "userName": "Jane"
    },
    "responseElements": null,
    "requestID": "ecd94349-b36f-44bf-b6f5-EXAMPLE9c463",
    "eventID": "2939ba50-1d26-4a5a-83bd-EXAMPLE85850",
    "readOnly": false,
    "eventType": "AwsApiCall",
    "managementEvent": true,
    "recipientAccountId": "555555555555",
    "eventCategory": "Management",
    "tlsDetails": {
        "tlsVersion": "TLSv1.2",
        "cipherSuite": "ECDHE-RSA-AES128-GCM-SHA256",
        "clientProvidedHostHeader": "iam.amazonaws.com"
    },
    "sessionCredentialFromConsole": "true"
}]}

The following example shows that the IAM user named Saanvi ran the aws iam create-role command to call the CreateRole action to create a role.

{"Records": [{
    "eventVersion": "1.08",
    "userIdentity": {
        "type": "IAMUser",
        "principalId": "AIDA6ON6E4XEGITEXAMPLE",
        "arn": "arn:aws:iam::777777777777:user/Saanvi",
        "accountId": "777777777777",
        "accessKeyId": "AKIAIOSFODNN7EXAMPLE",
        "userName": "Saanvi",
        "sessionContext": {
            "sessionIssuer": {},
            "webIdFederationData": {},
            "attributes": {
                "creationDate": "2023-07-19T21:11:57Z",
                "mfaAuthenticated": "false"
            }
        }
    },
    "eventTime": "2023-07-19T21:29:12Z",
    "eventSource": "iam.amazonaws.com",
    "eventName": "CreateRole",
    "awsRegion": "us-east-1",
    "sourceIPAddress": "192.0.2.0",
    "userAgent": "aws-cli/2.13.5 Python/3.11.4 Linux/4.14.255-314-253.539.amzn2.x86_64 exec-env/CloudShell exe/x86_64.amzn.2 prompt/off command/iam.create-role",
    "requestParameters": {
        "roleName": "TestRole",
        "description": "Allows EC2 instances to call AWS services on your behalf.",
        "assumeRolePolicyDocument": "{\"Version\":\"2012-10-17\",\"Statement\":[{\"Effect\":\"Allow\",\"Action\":[\"sts:AssumeRole\"],\"Principal\":{\"Service\":[\"ec2.amazonaws.com\"]}}]}"
    },
    "responseElements": {
        "role": {
            "assumeRolePolicyDocument": "%7B%22Version%22%3A%222012-10-17%22%2C%22Statement%22%3A%5B%7B%22Effect%22%3A%22Allow%22%2C%22Action%22%3A%5B%22sts%3AAssumeRole%22%5D%2C%22Principal%22%3A%7B%22Service%22%3A%5B%22ec2.amazonaws.com%22%5D%7D%7D%5D%7D",
            "arn": "arn:aws:iam::777777777777:role/TestRole",
            "roleId": "AROA6ON6E4XEFFEXAMPLE",
            "createDate": "Jul 19, 2023 9:29:12 PM",
            "roleName": "TestRole",
            "path": "/"
        }
    },
    "requestID": "ff38f36e-ebd3-425b-9939-EXAMPLE1bbe",
    "eventID": "9da77cd0-493f-4c89-8852-EXAMPLEa887c",
    "readOnly": false,
    "eventType": "AwsApiCall",
    "managementEvent": true,
    "recipientAccountId": "777777777777",
    "eventCategory": "Management",
    "tlsDetails": {
        "tlsVersion": "TLSv1.2",
        "cipherSuite": "ECDHE-RSA-AES128-GCM-SHA256",
        "clientProvidedHostHeader": "iam.amazonaws.com"
    },
    "sessionCredentialFromConsole": "true"
}]}

Error code and message log example

The following example shows that the IAM user named Terry ran the aws cloudtrail update-trail command to call the UpdateTrail action to update a trail named myTrail2, but the trail name was not found. The log shows this error in the errorCode and errorMessage elements. 

{"Records": [{
    "eventVersion": "1.09",
    "userIdentity": {
        "type": "IAMUser",
        "principalId": "AIDA6ON6E4XEGIEXAMPLE",
        "arn": "arn:aws:iam::111122223333:user/Terry",
        "accountId": "111122223333",
        "accessKeyId": "AKIAIOSFODNN7EXAMPLE",
        "userName": "Terry",
        "sessionContext": {
            "attributes": {
                "creationDate": "2023-07-19T21:11:57Z",
                "mfaAuthenticated": "false"
            }
        }
    },
    "eventTime": "2023-07-19T21:35:03Z",
    "eventSource": "cloudtrail.amazonaws.com",
    "eventName": "UpdateTrail",
    "awsRegion": "us-east-1",
    "sourceIPAddress": "192.0.2.0",
    "userAgent": "aws-cli/2.13.0 Python/3.11.4 Linux/4.14.255-314-253.539.amzn2.x86_64 exec-env/CloudShell exe/x86_64.amzn.2 prompt/off command/cloudtrail.update-trail",
    "errorCode": "TrailNotFoundException",
    "errorMessage": "Unknown trail: arn:aws:cloudtrail:us-east-1:111122223333:trail/myTrail2 for the user: 111122223333",
    "requestParameters": {
        "name": "myTrail2",
        "isMultiRegionTrail": true
    },
    "responseElements": null,
    "requestID": "28d2faaf-3319-4649-998d-EXAMPLE72818",
    "eventID": "694d604a-d190-4470-8dd1-EXAMPLEe20c1",
    "readOnly": false,
    "eventType": "AwsApiCall",
    "managementEvent": true,
    "recipientAccountId": "111122223333",
    "eventCategory": "Management",
    "tlsDetails": {
        "tlsVersion": "TLSv1.2",
        "cipherSuite": "ECDHE-RSA-AES128-GCM-SHA256",
        "clientProvidedHostHeader": "cloudtrail.us-east-1.amazonaws.com"
    },
    "sessionCredentialFromConsole": "true"
}]}

CloudTrail Insights event log example

The following example shows a CloudTrail Insights event log. An Insights event is actually a pair of events that mark the start and end of a period of unusual write management API activity or error response activity. The state field shows whether the event was logged at the start or end of the period of unusual activity. The event name, UpdateInstanceInformation, is the same name as the AWS Systems Manager API for which CloudTrail analyzed management events to determine that unusual activity occurred. Although the start and end events have unique eventID values, they also have a sharedEventID value that is used by the pair. The Insights event shows the baseline, or the normal pattern of activity, the insight, or average unusual activity that triggered the start Insights event, and in the end event, the insight value for the average unusual activity over the duration of the Insights event. For more information about CloudTrail Insights, see Logging Insights events.

{
    "Records": [{
        "eventVersion": "1.08",
        "eventTime": "2023-01-02T02:51:00Z",
        "awsRegion": "us-east-1",
        "eventID": "654a30ff-b0f3-4527-81b6-EXAMPLEf2393",
        "eventType": "AwsCloudTrailInsight",
        "recipientAccountId": "123456789012",
        "sharedEventID": "bcbfc274-8559-4a56-beb0-EXAMPLEa6c34",
        "insightDetails": {
            "state": "Start",
            "eventSource": "ssm.amazonaws.com",
            "eventName": "UpdateInstanceInformation",
            "insightType": "ApiCallRateInsight",
            "insightContext": {
                "statistics": {
                    "baseline": {
                        "average": 84.410596421
                    },
                    "insight": {
                        "average": 669
                    }
                }
            }
        },
        "eventCategory": "Insight"
    },
    {
        "eventVersion": "1.08",
        "eventTime": "2023-01-02T00:22:00Z",
        "awsRegion": "us-east-1",
        "eventID": "258de2fb-e2a9-4fb5-aeb2-EXAMPLE449a4",
        "eventType": "AwsCloudTrailInsight",
        "recipientAccountId": "123456789012",
        "sharedEventID": "8b74a7bc-d5d3-4d19-9d60-EXAMPLE08b51",
        "insightDetails": {
            "state": "End",
            "eventSource": "ssm.amazonaws.com",
            "eventName": "UpdateInstanceInformation",
            "insightType": "ApiCallRateInsight",
            "insightContext": {
                "statistics": {
                    "baseline": {
                        "average": 74.156423842
                    },
                    "insight": {
                        "average": 657
                    },
                    "insightDuration": 1
                }
            }
        },
        "eventCategory": "Insight"
    }]
}