Showing posts with label Security Group. Show all posts
Showing posts with label Security Group. Show all posts

Monday, October 21, 2019

Event ID 4752 - A member was removed from a security-disabled global group

Event ID 4752 - A member was removed from a security-disabled global group

Log Sample

{
 "EventTime": "2017/11/17 04:04:12"
 "Hostname": "WIN-AE4MOB56I4P.logpoint.com"
 "Keywords": -9214364837600034816
 "EventType": "AUDIT_SUCCESS"
 "SeverityValue": 2
 "Severity": "INFO"
 "EventID": 4752
 "SourceName": "Microsoft-Windows-Security-Auditing"
 "ProviderGuid": "{54849625-5478-4994-A5BA-3E3B0328C30D}"
 "Version": 0
 "Task": 13827
 "OpcodeValue": 0
 "RecordNumber": 1947168
 "ProcessID": 776
 "ThreadID": 5276
 "Channel": "Security"
 "Message": "A member was removed from a security-disabled global group."
 "Category": "Distribution Group Management"
 "Opcode": "Info"
 "MemberName": "CN=ros_group,DC=logpoint,DC=com"
 "MemberSid": "S-1-5-21-924791265-3775684568-2843720401-1112"
 "TargetUserName": "ros_group"
 "TargetDomainName": "logpoint"
 "TargetSid": "S-1-5-21-924791265-3775684568-2843720401-1112"
 "SubjectUserSid": "S-1-5-21-924791265-3775684568-2843720401-500"
 "SubjectUserName": "Administrator"
 "SubjectDomainName": "changeme"
 "SubjectLogonId": "0x33903e"
 "PrivilegeList": "-"
 "EventReceivedTime": "2017/11/17 04:04:12"
 "SourceModuleName": "in"
 "SourceModuleType": "im_msvistalog"
}


General Description
  • This event generates every time member was removed from the security-disabled (distribution) global group.
  • This event generates only on domain controllers.
Detail Description

Subject:
  • SubjectUserSID: SID of account that requested the “create Computer object” operation. 
  • SubjectUserName: the name of the account that requested the “create Computer object” operation.
  • SubjectDomainName: subject’s domain name. Formats vary, and include the following:
Domain NETBIOS name example: CONTOSO
Lowercase full domain name: contoso.local
Uppercase full domain name: CONTOSO.LOCAL

For some well-known security principals, such as LOCAL SERVICE or ANONYMOUS LOGON, the value of this field is “NT AUTHORITY”.
  • SubjectLogon ID: hexadecimal value that can help you correlate this event with recent events that might contain the same Logon ID, for example, “4624: An account was successfully logged on.”
Group (Target):
  • TargetSID: SID of created computer account.
  • TargetUserName: the name of the computer account that was created. For example: WIN81$
  • TargetDomainName: domain name of created computer account. Formats vary, and include the following:
Domain NETBIOS name example: CONTOSO
Lowercase full domain name: contoso.local
Uppercase full domain name: CONTOSO.LOCAL

Member:
  • Security ID: SID of account that was added to the group. Event Viewer automatically tries to resolve SIDs and show the group name. If the SID cannot be resolved, you will see the source data in the event.
  • Account Name: distinguished name of account that was added to the group. For example: “CN=Auditor,CN=Users,DC=contoso,DC=local”.
Attributes:
  • SAM Account Name: logon name for account used to support clients and servers from previous versions of Windows (pre-Windows 2000 logon name). The value of sAMAccountName attribute of new computer object. For example: WIN81$.
  • SID History: contains previous SIDs used for the object if the object was moved from another domain. 
Additional Information:
  • Privileges: the list of user privileges which were used during the operation, for example, SeBackupPrivilege. This parameter might not be captured in the event, and in that case appears as “-”.

Event ID 4753 - A security-disabled global group was deleted

Event ID 4753 - A security-disabled global group was deleted

Log Sample

{
"EventTime": "2017/11/17 04:04:12"
 "Hostname": "WIN-AE4MOB56I4P.changeme.com"
 "Keywords": -9214364837600034816
 "EventType": "AUDIT_SUCCESS"
 "SeverityValue": 2
 "Severity": "INFO"
 "EventID": 4753
 "SourceName": "Microsoft-Windows-Security-Auditing"
 "ProviderGuid": "{54849625-5478-4994-A5BA-3E3B0328C30D}"
 "Version": 0
 "Task": 13827
 "OpcodeValue": 0
 "RecordNumber": 2026256
 "ProcessID": 776
 "ThreadID": 5276
 "Channel": "Security"
 "Message": "A security-disabled global group was deleted."
 "Category": "Distribution Group Management"
 "Opcode": "Info"
 "TargetUserName": "ros_group"
 "TargetDomainName": "changeme"
 "TargetSid": "S-1-5-21-924791265-3775684568-2843720401-1112"
 "SubjectUserSid": "S-1-5-21-924791265-3775684568-2843720401-500"
 "SubjectUserName": "Administrator"
 "SubjectDomainName": "changeme"
 "SubjectLogonId": "0x33903e"
 "PrivilegeList": "-"
 "EventReceivedTime": "2017/11/17 04:04:12"
 "SourceModuleName": "in"
 "SourceModuleType": "im_msvistalog"
}


General Description
  • This event generates every time security-disabled (distribution) global group is deleted.
  • This event generates only on domain controllers.
SIEM Security Monitoring
  • If you have a list of critical distribution groups in the organization, and need to specifically monitor these groups for any change, especially group deletion, monitor events with the “Group\Group Name” values that correspond to the critical distribution groups.
  • If you need to monitor each time a distribution group is deleted, to see who deleted it and when, monitor this event. Typically, this event is used as an informational event, to be reviewed if needed.
Detail Description

Subject:
  • SubjectUserSID: SID of account that requested the “create Computer object” operation. 
  • SubjectUserName: the name of the account that requested the “create Computer object” operation.
  • SubjectDomainName: subject’s domain name. Formats vary, and include the following:
Domain NETBIOS name example: CONTOSO
Lowercase full domain name: contoso.local
Uppercase full domain name: CONTOSO.LOCAL

For some well-known security principals, such as LOCAL SERVICE or ANONYMOUS LOGON, the value of this field is “NT AUTHORITY”.
  • SubjectLogon ID: hexadecimal value that can help you correlate this event with recent events that might contain the same Logon ID, for example, “4624: An account was successfully logged on.”
Group (Target):
  • TargetSID: SID of created computer account.
  • TargetUserName: the name of the computer account that was created. For example: WIN81$
  • TargetDomainName: domain name of created computer account. Formats vary, and include the following:
Domain NETBIOS name example: CONTOSO
Lowercase full domain name: contoso.local
Uppercase full domain name: CONTOSO.LOCAL

Attributes:
  • SAM Account Name: logon name for account used to support clients and servers from previous versions of Windows (pre-Windows 2000 logon name). The value of sAMAccountName attribute of new computer object. For example: WIN81$.
  • SID History: contains previous SIDs used for the object if the object was moved from another domain. 
Additional Information:
  • Privileges: the list of user privileges which were used during the operation, for example, SeBackupPrivilege. This parameter might not be captured in the event, and in that case appears as “-”.

Monday, October 14, 2019

Event ID 4751 - A member was added to a security-disabled global group

Event ID 4751 - A member was added to a security-disabled global group

Log Sample

{
 "EventTime": "2017/11/17 04:04:12"
 "Hostname": "WIN-AE4MOB56I4P.logpoint.com"
 "Keywords": -9214364837600034816
 "EventType": "AUDIT_SUCCESS"
 "SeverityValue": 2
 "Severity": "INFO"
 "EventID": 4751
 "SourceName": "Microsoft-Windows-Security-Auditing"
 "ProviderGuid": "{54849625-5478-4994-A5BA-3E3B0328C30D}"
 "Version": 0
 "Task": 13827
 "OpcodeValue": 0
 "RecordNumber": 1938909
 "ProcessID": 776
 "ThreadID": 2032
 "Channel": "Security"
 "Message": "A member was added to a security-disabled global group."
 "Category": "Distribution Group Management"
 "Opcode": "Info"
 "MemberName": "CN=sigsan_global,DC=logpoint,DC=com"
 "MemberSid": "S-1-5-21-924791265-3775684568-2843720401-1111"
 "TargetUserName": "sigsan_global"
 "TargetDomainName": "changeme"
 "TargetSid": "S-1-5-21-924791265-3775684568-2843720401-1111"
 "SubjectUserSid": "S-1-5-21-924791265-3775684568-2843720401-500"
 "SubjectUserName": "Administrator"
 "SubjectDomainName": "logpoint"
 "SubjectLogonId": "0x33903e"
 "PrivilegeList": "-"
 "EventReceivedTime": "2017/11/17 04:04:12"
 "SourceModuleName": "in"
 "SourceModuleType": "im_msvistalog"
}


General Description
  • This event generates every time a new member was added to a security-disabled (distribution) global group.
  • This event generates only on domain controllers.
Detail Description

Subject:
  • SubjectUserSID: SID of account that requested the “create Computer object” operation. 
  • SubjectUserName: the name of the account that requested the “create Computer object” operation.
  • SubjectDomainName: subject’s domain name. Formats vary, and include the following:
Domain NETBIOS name example: CONTOSO
Lowercase full domain name: contoso.local
Uppercase full domain name: CONTOSO.LOCAL

For some well-known security principals, such as LOCAL SERVICE or ANONYMOUS LOGON, the value of this field is “NT AUTHORITY”.
  • SubjectLogon ID: hexadecimal value that can help you correlate this event with recent events that might contain the same Logon ID, for example, “4624: An account was successfully logged on.”
Group (Target):
  • TargetSID: SID of created computer account.
  • TargetUserName: the name of the computer account that was created. For example: WIN81$
  • TargetDomainName: domain name of created computer account. Formats vary, and include the following:
Domain NETBIOS name example: CONTOSO
Lowercase full domain name: contoso.local
Uppercase full domain name: CONTOSO.LOCAL

Member:
  • Security ID: SID of account that was added to the group. Event Viewer automatically tries to resolve SIDs and show the group name. If the SID cannot be resolved, you will see the source data in the event.
  • Account Name: distinguished name of account that was added to the group. For example: “CN=Auditor,CN=Users,DC=contoso,DC=local”.
Attributes:
  • SAM Account Name: logon name for account used to support clients and servers from previous versions of Windows (pre-Windows 2000 logon name). The value of sAMAccountName attribute of new computer object. For example: WIN81$.
  • SID History: contains previous SIDs used for the object if the object was moved from another domain. 
Additional Information:
  • Privileges: the list of user privileges which were used during the operation, for example, SeBackupPrivilege. This parameter might not be captured in the event, and in that case appears as “-”.

Sunday, October 6, 2019

Event ID 4749 - A security-disabled global group was created

Event ID 4749 - A security-disabled global group was created

Log Sample

{
 "EventTime": "2017/11/17 04:04:12"
 "Hostname": "WIN-AE4MOB56I4P.changeme.com"
 "Keywords": -9214364837600034816
 "EventType": "AUDIT_SUCCESS"
 "SeverityValue": 2
 "Severity": "INFO"
 "EventID": 4749
 "SourceName": "Microsoft-Windows-Security-Auditing"
 "ProviderGuid": "{54849625-5478-4994-A5BA-3E3B0328C30D}"
 "Version": 0
 "Task": 13827
 "OpcodeValue": 0
 "RecordNumber": 2034819
 "ProcessID": 776
 "ThreadID": 2032
 "Channel": "Security"
 "Message": "A security-disabled global group was created.
 "Category": "Distribution Group Management"
 "Opcode": "Info"
 "TargetUserName": "sig_group"
 "TargetDomainName": "changeme"
 "TargetSid": "S-1-5-21-924791265-3775684568-2843720401-1113"
 "SubjectUserSid": "S-1-5-21-924791265-3775684568-2843720401-500"
 "SubjectUserName": "Administrator"
 "SubjectDomainName": "changeme"
 "SubjectLogonId": "0x33903e"
 "PrivilegeList": "-"
 "SamAccountName": "sig_group"
 "SidHistory": "-"
 "EventReceivedTime": "2017/11/17 04:04:12"
 "SourceModuleName": "in"
 "SourceModuleType": "im_msvistalog"
}

General Description
  • This event generates every time a new security-disabled (distribution) global group was created.
  • This event generates only on domain controllers.
SIEM: Security Consideration
  • If you need to monitor each time a new distribution group is created, to see who created the group and when, monitor this event. Typically, this event is used as an informational event, to be reviewed if needed.
  • If your organization has naming conventions for account names, monitor “Attributes\SAM Account Name” for names that don’t comply with the naming conventions.

Detail Description

Subject:
  • SubjectUserSID: SID of account that requested the “create Computer object” operation. 
  • SubjectUserName: the name of the account that requested the “create Computer object” operation.
  • SubjectDomainName: subject’s domain name. Formats vary, and include the following:
Domain NETBIOS name example: CONTOSO
Lowercase full domain name: contoso.local
Uppercase full domain name: CONTOSO.LOCAL

For some well-known security principals, such as LOCAL SERVICE or ANONYMOUS LOGON, the value of this field is “NT AUTHORITY”.
  • SubjectLogon ID: hexadecimal value that can help you correlate this event with recent events that might contain the same Logon ID, for example, “4624: An account was successfully logged on.”

New Group (Target):
  • TargetSID: SID of created computer account.
  • TargetUserName: the name of the computer account that was created. For example: WIN81$
  • TargetDomainName: domain name of created computer account. Formats vary, and include the following:
Domain NETBIOS name example: CONTOSO
Lowercase full domain name: contoso.local
Uppercase full domain name: CONTOSO.LOCAL

Attributes:
  • SAM Account Name: logon name for account used to support clients and servers from previous versions of Windows (pre-Windows 2000 logon name). The value of sAMAccountName attribute of new computer object. For example: WIN81$.
  • SID History: contains previous SIDs used for the object if the object was moved from another domain. 
Additional Information:
  • Privileges: the list of user privileges which were used during the operation, for example, SeBackupPrivilege. This parameter might not be captured in the event, and in that case appears as “-”.

Friday, September 27, 2019

Security Group Management in Windows System

There are various events that gets logged when following security group management tasks are performed
  • A security group is created, changed, or deleted. 
  • A member is added to or removed from a security group. 
  • A group's type is changed. 
The volume of this event being generated is low. And by default success events are configured to be logged by Microsoft. If policy setting are configured following are the lists of event that gets generated

eventId description
4727 A security-enabled global group was created.
4728 A member was added to a security-enabled global group.
4729 A member was removed from a security-enabled global group.
4730 A security-enabled global group was deleted.
4731 A security-enabled local group was created.
4732 A member was added to a security-enabled local group.
4733 A member was removed from a security-enabled local group.
4734 A security-enabled local group was deleted.
4735 A security-enabled local group was changed.
4737 A security-enabled global group was changed.
4754 A security-enabled universal group was created.
4755 A security-enabled universal group was changed.
4756 A member was added to a security-enabled universal group.
4757 A member was removed from a security-enabled universal group.
4758 A security-enabled universal group was deleted.
4764 A group's type was changed.

How should these events be looked in SIEM tool?
Alert rules. Rules can be specific to above mentioned eventId or generic to Application Group Management like
LogSource=Windows eventId IN [4727, 4728, 4729, 4730, 4731, 4732, 4733, 4734, 4735, 4737, 4754, 4755, 4756, 4757, 4758, 4764]

What fields to monitor?
timestamp, who performed, group name, operationType and other important information depending on the event generated.


Wednesday, March 27, 2019

Event ID 4750 - A security-disabled global group was changed

Event ID 4750 - A security-disabled global group was changed

Log Sample

{
 "EventTime": "2017/11/17 04:04:12"
 "Hostname": "WIN-AE4MOB56I4P.changeme.com"
 "Keywords": -9214364837600034816
 "EventType": "AUDIT_SUCCESS"
 "SeverityValue": 2
 "Severity": "INFO"
 "EventID": 4750
 "SourceName": "Microsoft-Windows-Security-Auditing"
 "ProviderGuid": "{54849625-5478-4994-A5BA-3E3B0328C30D}"
 "Version": 0
 "Task": 13827
 "OpcodeValue": 0
 "RecordNumber": 1912984
 "ProcessID": 776
 "ThreadID": 2032
 "Channel": "Security"
 "Message": "A security-disabled global group was changed.
 "Category": "Distribution Group Management"
 "Opcode": "Info"
 "TargetUserName": "sigsan_global"
 "TargetDomainName": "changeme"
 "TargetSid": "S-1-5-21-924791265-3775684568-2843720401-1111"
 "SubjectUserSid": "S-1-5-21-924791265-3775684568-2843720401-500"
 "SubjectUserName": "Administrator"
 "SubjectDomainName": "changeme"
 "SubjectLogonId": "0x33903e"
 "PrivilegeList": "-"
 "SamAccountName": "-"
 "SidHistory": "-"
 "EventReceivedTime": "2017/11/17 04:04:12"
 "SourceModuleName": "in"
 "SourceModuleType": "im_msvistalog"
}


General Description
  • This event generates every time security-disabled (distribution) global group is changed.
  • This event generates only on domain controllers.
  • From 4750 event you can get information about changes of sAMAccountName and sIDHistory attributes or you will see that something changed, but will not be able to see what exactly changed.
SIEM: Security Consideration
  • If you have a list of critical distribution groups in the organization, and need to specifically monitor these groups for any change, monitor events with the “Group\Group Name” values that correspond to the critical distribution groups.
  • If you need to monitor each time a new distribution group is created, to see who created the group and when, monitor this event. Typically, this event is used as an informational event, to be reviewed if needed.
  • If your organization has naming conventions for account names, monitor “Attributes\SAM Account Name” for names that don’t comply with the naming conventions.

Detail Description

Subject:
  • SubjectUserSID: SID of account that requested the “create Computer object” operation. 
  • SubjectUserName: the name of the account that requested the “create Computer object” operation.
  • SubjectDomainName: subject’s domain name. Formats vary, and include the following:
Domain NETBIOS name example: CONTOSO
Lowercase full domain name: contoso.local
Uppercase full domain name: CONTOSO.LOCAL

For some well-known security principals, such as LOCAL SERVICE or ANONYMOUS LOGON, the value of this field is “NT AUTHORITY”.
  • SubjectLogon ID: hexadecimal value that can help you correlate this event with recent events that might contain the same Logon ID, for example, “4624: An account was successfully logged on.”

New Group (Target):
  • TargetSID: SID of created computer account.
  • TargetUserName: the name of the computer account that was created. For example: WIN81$
  • TargetDomainName: domain name of created computer account. Formats vary, and include the following:
Domain NETBIOS name example: CONTOSO
Lowercase full domain name: contoso.local
Uppercase full domain name: CONTOSO.LOCAL

Attributes:
  • SAM Account Name: logon name for account used to support clients and servers from previous versions of Windows (pre-Windows 2000 logon name). The value of sAMAccountName attribute of new computer object. For example: WIN81$.
  • SID History: contains previous SIDs used for the object if the object was moved from another domain. 
Additional Information:
  • Privileges: the list of user privileges which were used during the operation, for example, SeBackupPrivilege. This parameter might not be captured in the event, and in that case appears as “-”.

Saturday, March 23, 2019

Windows Event Log - Security Group Management


Event IdDescription
4727A security-enabled global group was created.
4728A member was added to a security-enabled global group.
4729A member was removed from a security-enabled global group.
4730A security-enabled global group was deleted.
4731A security-enabled local group was created.
4732A member was added to a security-enabled local group.
4733A member was removed from a security-enabled local group.
4734A security-enabled local group was deleted.
4735A security-enabled local group was changed.
4737A security-enabled global group was changed.
4754A security-enabled universal group was created.
4755A security-enabled universal group was changed.
4756A member was added to a security-enabled universal group.
4757A member was removed from a security-enabled universal group.
4758A security-enabled universal group was deleted.
4764A group's type was changed.

Wednesday, December 26, 2018

AD - Security and Distribution Group

When creating a group in Microsoft Active Directory you are given two options to choose from. One Security and the other is distribution. These two groups serves different purpose and it is vital to understand the purpose before you create a group. Let's look what these groups allows you to do.

Security Group
- Allows you to manage user and computer access to shared resources.
- Allows you to control who receives group policy settings.
- Allows you to set permissions once on multiple computers, then change the membership of the group as your needs change.
- Also, allows you to use these groups as email distribution lists.

Distribution Group
- Distribution groups are intended to be used as email distribution lists and used with applications such as Microsoft Exchange or Outlook. This group allows you to add and remove contacts from the list so that they will or will not receive email sent to the distribution group.
- However, you will not be able to use distribution groups for the purpose of assigning permissions on any objects. Also, you can't use them to filter group policy settings.