5145(S, F): A network share object was checked to see whether client can be granted desired access.
Subcategory: Audit Detailed File Share
Event Description:
This event generates every time network share object (file or folder) was accessed.
Important: Failure events are generated only when access is denied at the file share level. No events are generated if access was denied on the file system (NTFS) level.
Note For recommendations, see Security Monitoring Recommendations for this event.
Event XML:
- <Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
- <System>
<Provider Name="Microsoft-Windows-Security-Auditing" Guid="{54849625-5478-4994-A5BA-3E3B0328C30D}" />
<EventID>5145</EventID>
<Version>0</Version>
<Level>0</Level>
<Task>12811</Task>
<Opcode>0</Opcode>
<Keywords>0x8020000000000000</Keywords>
<TimeCreated SystemTime="2015-09-17T23:54:48.941761700Z" />
<EventRecordID>267092</EventRecordID>
<Correlation />
<Execution ProcessID="516" ThreadID="524" />
<Channel>Security</Channel>
<Computer>DC01.contoso.local</Computer>
<Security />
</System>
- <EventData>
<Data Name="SubjectUserSid">S-1-5-21-3457937927-2839227994-823803824-1104</Data>
<Data Name="SubjectUserName">dadmin</Data>
<Data Name="SubjectDomainName">CONTOSO</Data>
<Data Name="SubjectLogonId">0x38d34</Data>
<Data Name="ObjectType">File</Data>
<Data Name="IpAddress">fe80::31ea:6c3c:f40d:1973</Data>
<Data Name="IpPort">56926</Data>
<Data Name="ShareName">\\\\\*\\Documents</Data>
<Data Name="ShareLocalPath">\\??\\C:\\Documents</Data>
<Data Name="RelativeTargetName">Bginfo.exe</Data>
<Data Name="AccessMask">0x100081</Data>
<Data Name="AccessList">%%1541 %%4416 %%4423</Data>
<Data Name="AccessReason">%%1541: %%1801 D:(A;;FA;;;WD) %%4416: %%1801 D:(A;;FA;;;WD) %%4423: %%1801 D:(A;;FA;;;WD)</Data>
</EventData>
</Event>
Required Server Roles: None.
Minimum OS Version: Windows Server 2008, Windows Vista.
Event Versions: 0.
Field Descriptions:
Subject:
- Security ID [Type = SID]: SID of account that requested access to network share object. Event Viewer automatically tries to resolve SIDs and show the account name. If the SID can't be resolved, you'll see the source data in the event.
Note A security identifier (SID) is a unique value of variable length used to identify a trustee (security principal). Each account has a unique SID that is issued by an authority, such as an Active Directory domain controller, and stored in a security database. Each time a user logs on, the system retrieves the SID for that user from the database and places it in the access token for that user. The system uses the SID in the access token to identify the user in all subsequent interactions with Windows security. When a SID has been used as the unique identifier for a user or group, it cannot ever be used again to identify another user or group. For more information about SIDs, see Security identifiers.
Account Name [Type = UnicodeString]: the name of the account that requested access to network share object.
Account Domain [Type = UnicodeString]: subject’s domain or computer name. Formats vary, and include the following ones:
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”.
For local user accounts, this field will contain the name of the computer or device that this account belongs to, for example: “Win81”.
Logon ID [Type = HexInt64]: 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.”
Network Information:
Object Type [Type = UnicodeString]: The type of an object that was accessed during the operation. Always “File” for this event.
The following table contains the list of the most common Object Types:
| Directory | Event | Timer | Device |
|---|---|---|---|
| Mutant | Type | File | Token |
| Thread | Section | WindowStation | DebugObject |
| FilterCommunicationPort | EventPair | Driver | IoCompletion |
| Controller | SymbolicLink | WmiGuid | Process |
| Profile | Desktop | KeyedEvent | Adapter |
| Key | WaitablePort | Callback | Semaphore |
| Job | Port | FilterConnectionPort | ALPC Port |
Source Address [Type = UnicodeString]: source IP address from which access was performed.
IPv6 address or ::ffff:IPv4 address of a client.
::1 or 127.0.0.1 means localhost.
Source Port [Type = UnicodeString]: source TCP or UDP port that was used from remote or local machine to request the access.
- 0 for local access attempts.
Share Information:
Share Name [Type = UnicodeString]: the name of accessed network share. The format is: \\*\SHARE_NAME.
Share Path [Type = UnicodeString]: the full system (NTFS) path for accessed share. The format is: \\??\PATH. Can be empty, for example for Share Name: \\*\IPC$.
Relative Target Name [Type = UnicodeString]: relative name of the accessed target file or folder. This file-path is relative to the network share. If access was requested for the share itself, then this field appears as “\”.
Access Request Information:
Access Mask [Type = HexInt32]: the sum of hexadecimal values of requested access rights. See Table of file access codes for different hexadecimal values for access rights.
Accesses [Type = UnicodeString]: the list of access rights that were requested by Subject\Security ID. These access rights depend on Object Type.
Table of file access codes
| Access | Hex Value, Schema Value |
Description |
|---|---|---|
| ReadData (or ListDirectory) | 0x1, %%4416 |
ReadData - For a file object, the right to read the corresponding file data. For a directory object, the right to read the corresponding directory data. ListDirectory - For a directory, the right to list the contents of the directory. |
| WriteData (or AddFile) | 0x2, %%4417 |
WriteData - For a file object, the right to write data to the file. For a directory object, the right to create a file in the directory (FILE_ADD_FILE). AddFile - For a directory, the right to create a file in the directory. |
| AppendData (or AddSubdirectory or CreatePipeInstance) | 0x4, %%4418 |
AppendData - For a file object, the right to append data to the file. (For local files, write operations won't overwrite existing data if this flag is specified without FILE_WRITE_DATA.) For a directory object, the right to create a subdirectory (FILE_ADD_SUBDIRECTORY). AddSubdirectory - For a directory, the right to create a subdirectory. CreatePipeInstance - For a named pipe, the right to create a pipe. |
| ReadEA | 0x8, %%4419 |
The right to read extended file attributes. |
| WriteEA | 0x10, %%4420 |
The right to write extended file attributes. |
| Execute/Traverse | 0x20, %%4421 |
Execute - For a native code file, the right to execute the file. This access right given to scripts may cause the script to be executable, depending on the script interpreter. Traverse - For a directory, the right to traverse the directory. By default, users are assigned the BYPASS_TRAVERSE_CHECKING privilege, which ignores the FILE_TRAVERSE access right. For more information, see the remarks in File Security and Access Rights. |
| DeleteChild | 0x40, %%4422 |
For a directory, the right to delete a directory and all the files it contains, including read-only files. |
| ReadAttributes | 0x80, %%4423 |
The right to read file attributes. |
| WriteAttributes | 0x100, %%4424 |
The right to write file attributes. |
| DELETE | 0x10000, %%1537 |
The right to delete the object. |
| READ_CONTROL | 0x20000, %%1538 |
The right to read the information in the object's security descriptor, not including the information in the system access control list (SACL). |
| WRITE_DAC | 0x40000, %%1539 |
The right to modify the discretionary access control list (DACL) in the object's security descriptor. |
| WRITE_OWNER | 0x80000, %%1540 |
The right to change the owner in the object's security descriptor |
| SYNCHRONIZE | 0x100000, %%1541 |
The right to use the object for synchronization. This right enables a thread to wait until the object is in the signaled state. Some object types don't support this access right. |
| ACCESS_SYS_SEC | 0x1000000, %%1542 |
The ACCESS_SYS_SEC access right controls the ability to get or set the SACL in an object's security descriptor. |
Table 13. File access codes.
Access Check Results [Type = UnicodeString]: the list of access check results. The format of the result is:
REQUESTED_ACCESS: RESULT ACE_WHICH_ ALLOWED_OR_DENIED_ACCESS.
REQUESTED_ACCESS – the name of requested access. See Table of file access codes, earlier in this topic.
RESULT:
Granted by – if access was granted.
Denied by – if access was denied.
ACE_WHICH_ ALLOWED_OR_DENIED_ACCESS: the Security Descriptor Definition Language (SDDL) value for Access Control Entry (ACE), which granted or denied access.
Note The Security Descriptor Definition Language (SDDL) defines string elements for enumerating information contained in the security descriptor.
Example:
O:BAG:SYD:(D;;0xf0007;;;AN)(D;;0xf0007;;;BG)(A;;0xf0007;;;SY)(A;;0×7;;;BA)S:ARAI(AU;SAFA;DCLCRPCRSDWDWO;;;WD)
- O: = Owner. SID of specific security principal, or reserved (pre-defined) value, for example: BA (BUILTIN_ADMINISTRATORS), WD (Everyone), SY (LOCAL_SYSTEM), etc. See the list of possible values in the table below.
SDDL values for Access Control Entry
| Value | Description | Value | Description |
|---|---|---|---|
| "AO" | Account operators | "PA" | Group Policy administrators |
| "RU" | Alias to allow previous Windows 2000 | "IU" | Interactively logged-on user |
| "AN" | Anonymous logon | "LA" | Local administrator |
| "AU" | Authenticated users | "LG" | Local guest |
| "BA" | Built-in administrators | "LS" | Local service account |
| "BG" | Built-in guests | "SY" | Local system |
| "BO" | Backup operators | "NU" | Network sign-in user |
| "BU" | Built-in users | "NO" | Network configuration operators |
| "CA" | Certificate server administrators | "NS" | Network service account |
| "CG" | Creator group | "PO" | Printer operators |
| "CO" | Creator owner | "PS" | Personal self |
| "DA" | Domain administrators | "PU" | Power users |
| "DC" | Domain computers | "RS" | RAS servers group |
| "DD" | Domain controllers | "RD" | Terminal server users |
| "DG" | Domain guests | "RE" | Replicator |
| "DU" | Domain users | "RC" | Restricted code |
| "EA" | Enterprise administrators | "SA" | Schema administrators |
| "ED" | Enterprise domain controllers | "SO" | Server operators |
| "WD" | Everyone | "SU" | Service sign-in user |
- G: = Primary Group.
- D: = DACL Entries.
- S: = SACL Entries.
DACL/SACL entry format: entry_type:inheritance_flags(ace_type;ace_flags;rights;object_guid;inherit_object_guid;account_sid)
Example: D:(A;;FA;;;WD)
- entry_type:
“D” - DACL
“S” - SACL
- inheritance_flags:
"P” - SDDL_PROTECTED, Inheritance from containers that are higher in the folder hierarchy are blocked.
"AI" - SDDL_AUTO_INHERITED, Inheritance is allowed, assuming that "P" Isn't also set.
"AR" - SDDL_AUTO_INHERIT_REQ, Child objects inherit permissions from this object.
- ace_type:
"A" - ACCESS ALLOWED
"D" - ACCESS DENIED
"OA" - OBJECT ACCESS ALLOWED: only applies to a subset of the object(s).
"OD" - OBJECT ACCESS DENIED: only applies to a subset of the object(s).
"AU" - SYSTEM AUDIT
"A" - SYSTEM ALARM
"OU" - OBJECT SYSTEM AUDIT
"OL" - OBJECT SYSTEM ALARM
- ace_flags:
"CI" - CONTAINER INHERIT: Child objects that are containers, such as directories, inherit the ACE as an explicit ACE.
"OI" - OBJECT INHERIT: Child objects that aren't containers inherit the ACE as an explicit ACE.
"NP" - NO PROPAGATE: only immediate children inherit this ace.
"IO" - INHERITANCE ONLY: ace doesn’t apply to this object, but may affect children via inheritance.
"ID" - ACE IS INHERITED
"SA" - SUCCESSFUL ACCESS AUDIT
"FA" - FAILED ACCESS AUDIT
- rights: A hexadecimal string that denotes the access mask or reserved value, for example: FA (File All Access), FX (File Execute), FW (File Write), etc.
| Value | Description | Value | Description |
|---|---|---|---|
| Generic access rights | Directory service access rights | ||
| "GA" | GENERIC ALL | "RC" | Read Permissions |
| "GR" | GENERIC READ | "SD" | Delete |
| "GW" | GENERIC WRITE | "WD" | Modify Permissions |
| "GX" | GENERIC EXECUTE | "WO" | Modify Owner |
| File access rights | "RP" | Read All Properties | |
| "FA" | FILE ALL ACCESS | "WP" | Write All Properties |
| "FR" | FILE GENERIC READ | "CC" | Create All Child Objects |
| "FW" | FILE GENERIC WRITE | "DC" | Delete All Child Objects |
| "FX" | FILE GENERIC EXECUTE | "LC" | List Contents |
| Registry key access rights | "SW" | All Validated Writes | |
| "KA" | "LO" | "LO" | List Object |
| "K" | KEY READ | "DT" | Delete Subtree |
| "KW" | KEY WRITE | "CR" | All Extended Rights |
| "KX" | KEY EXECUTE |
- object_guid: N/A
- inherit_object_guid: N/A
- account_sid: SID of specific security principal, or reserved value, for example: AN (Anonymous), WD (Everyone), SY (LOCAL_SYSTEM), etc. For more information, see the table above.
For more information about SDDL syntax, see these articles: https://msdn.microsoft.com/library/cc230374.aspx, https://msdn.microsoft.com/library/windows/hardware/aa374892(v=vs.85).aspx.
Security Monitoring Recommendations
For 5145(S, F): A network share object was checked to see whether client can be granted desired access.
Important For this event, also see Appendix A: Security monitoring recommendations for many audit events.
Monitor this event if the Network Information\Source Address isn't from your internal IP range.
Monitor this event if the Network Information\Source Address shouldn't be able to connect with the specific computer (Computer:).
If you have critical files or folders on specific network shares, for which you need to monitor access attempts (Success and Failure), monitor for specific Share Information\Share Name and Share Information\Relative Target Name.
If you have domain or local accounts that should only be able to access a specific list of shared files or folders, you can monitor for access attempts outside the allowed list.
We recommend that you monitor for these Access Request Information\Accesses rights (especially for Failure):
WriteData (or AddFile)
AppendData (or AddSubdirectory or CreatePipeInstance)
WriteEA
DeleteChild
WriteAttributes
DELETE
WRITE_DAC
WRITE_OWNER