Last eveningmy system suffered a Power Off event of unknown nature while I was asleep.OS: Vista SP1 x64, installed just a few days ago. Functioned properly in vista x86 for about a year.There is suspicious secuirity account activity during the night ending in Power Off event. I admit I've been lazy with my local group of computers not changing the workgroup name, and using a non-cryptograpic password over 8 characters.My questions: Why the hell suddenly at 2am when no scheduled tasks happen that there is a burst of security activity? Why are the priv's to system being changed? I'm speculating that some mildly broken Trojan may have gotten onto my machine, and is throwing some low level events, and then crashing the system.Anyway here is the Security Log. Have I gone insane or is the power off event related to something else entirely?As usual the last event before power off is first. That second event makes me quite suspicious. Log Name: SecuritySource: Microsoft-Windows-Security-AuditingDate: 1/9/2009 2:11:54 AMEvent ID: 4672Task Category: Special LogonLevel: InformationKeywords: Audit SuccessUser: N/AComputer: AuroraDescription:Special privileges assigned to new logon. Subject:Security ID:SYSTEMAccount Name:SYSTEMAccount Domain:NT AUTHORITYLogon ID:0x3e7 Privileges:SeAssignPrimaryTokenPrivilegeSeTcbPrivilegeSeSecurityPrivilegeSeTakeOwnershipPrivilegeSeLoadDriverPrivilegeSeBackupPrivilegeSeRestorePrivilegeSeDebugPrivilegeSeAuditPrivilegeSeSystemEnvironmentPrivilegeSeImpersonatePrivilegeEvent 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>4672</EventID> <Version>0</Version> <Level>0</Level> <Task>12548</Task> <Opcode>0</Opcode> <Keywords>0x8020000000000000</Keywords> <TimeCreated SystemTime="2009-01-09T10:11:54.026Z" /> <EventRecordID>1546</EventRecordID> <Correlation /> <Execution ProcessID="636" ThreadID="2428" /> <Channel>Security</Channel> <Computer>Aurora</Computer> <Security /> </System> <EventData> <Data Name="SubjectUserSid">S-1-5-18</Data> <Data Name="SubjectUserName">SYSTEM</Data> <Data Name="SubjectDomainName">NT AUTHORITY</Data> <Data Name="SubjectLogonId">0x3e7</Data> <Data Name="PrivilegeList">SeAssignPrimaryTokenPrivilegeSeTcbPrivilegeSeSecurityPrivilegeSeTakeOwnershipPrivilegeSeLoadDriverPrivilegeSeBackupPrivilegeSeRestorePrivilegeSeDebugPrivilegeSeAuditPrivilegeSeSystemEnvironmentPrivilegeSeImpersonatePrivilege</Data> </EventData></Event> Log Name: SecuritySource: Microsoft-Windows-Security-AuditingDate: 1/9/2009 2:11:54 AMEvent ID: 4624Task Category: LogonLevel: InformationKeywords: Audit SuccessUser: N/AComputer: AuroraDescription:An account was successfully logged on. Subject:Security ID:SYSTEMAccount Name:AURORA$Account Domain:WORKGROUPLogon ID:0x3e7 Logon Type:5 New Logon:Security ID:SYSTEMAccount Name:SYSTEMAccount Domain:NT AUTHORITYLogon ID:0x3e7Logon GUID:{00000000-0000-0000-0000-000000000000} Process Information:Process ID:0x270Process Name:C:\Windows\System32\services.exe Network Information:Workstation Name:Source Network Address:-Source Port:- Detailed Authentication Information:Logon Process:Advapi Authentication Package:NegotiateTransited Services:-Package Name (NTLM only):-Key Length:0 This event is generated when a logon session is created. It is generated on the computer that was accessed. The subject fields indicate the account on the local system which requested the logon. This is most commonly a service such as the Server service, or a local process such as Winlogon.exe or Services.exe. The logon type field indicates the kind of logon that occurred. The most common types are 2 (interactive) and 3 (network). The New Logon fields indicate the account for whom the new logon was created, i.e. the account that was logged on. The network fields indicate where a remote logon request originated. Workstation name is not always available and may be left blank in some cases. The authentication information fields provide detailed information about this specific logon request.- Logon GUID is a unique identifier that can be used to correlate this event with a KDC event.- Transited services indicate which intermediate services have participated in this logon request.- Package name indicates which sub-protocol was used among the NTLM protocols.- Key length indicates the length of the generated session key. This will be 0 if no session key was requested.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>4624</EventID> <Version>0</Version> <Level>0</Level> <Task>12544</Task> <Opcode>0</Opcode> <Keywords>0x8020000000000000</Keywords> <TimeCreated SystemTime="2009-01-09T10:11:54.026Z" /> <EventRecordID>1545</EventRecordID> <Correlation /> <Execution ProcessID="636" ThreadID="2428" /> <Channel>Security</Channel> <Computer>Aurora</Computer> <Security /> </System> <EventData> <Data Name="SubjectUserSid">S-1-5-18</Data> <Data Name="SubjectUserName">AURORA$</Data> <Data Name="SubjectDomainName">WORKGROUP</Data> <Data Name="SubjectLogonId">0x3e7</Data> <Data Name="TargetUserSid">S-1-5-18</Data> <Data Name="TargetUserName">SYSTEM</Data> <Data Name="TargetDomainName">NT AUTHORITY</Data> <Data Name="TargetLogonId">0x3e7</Data> <Data Name="LogonType">5</Data> <Data Name="LogonProcessName">Advapi </Data> <Data Name="AuthenticationPackageName">Negotiate</Data> <Data Name="WorkstationName"> </Data> <Data Name="LogonGuid">{00000000-0000-0000-0000-000000000000}</Data> <Data Name="TransmittedServices">-</Data> <Data Name="LmPackageName">-</Data> <Data Name="KeyLength">0</Data> <Data Name="ProcessId">0x270</Data> <Data Name="ProcessName">C:\Windows\System32\services.exe</Data> <Data Name="IpAddress">-</Data> <Data Name="IpPort">-</Data> </EventData></Event> Log Name: SecuritySource: Microsoft-Windows-Security-AuditingDate: 1/9/2009 2:11:54 AMEvent ID: 4648Task Category: LogonLevel: InformationKeywords: Audit SuccessUser: N/AComputer: AuroraDescription:A logon was attempted using explicit credentials. Subject:Security ID:SYSTEMAccount Name:AURORA$Account Domain:WORKGROUPLogon ID:0x3e7Logon GUID:{00000000-0000-0000-0000-000000000000} Account Whose Credentials Were Used:Account Name:SYSTEMAccount Domain:NT AUTHORITYLogon GUID:{00000000-0000-0000-0000-000000000000} Target Server:Target Server Name:localhostAdditional Information:localhost Process Information:Process ID:0x270Process Name:C:\Windows\System32\services.exe Network Information:Network Address:-Port:- This event is generated when a process attempts to log on an account by explicitly specifying that accounts credentials. This most commonly occurs in batch-type configurations such as scheduled tasks, or when using the RUNAS command.Event Xml:<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event"> <System> <Provider Name="Microsoft-Windows-Security-Auditing" Guid="{54849625-5478-4994-a5ba-3e3b0328c30d}" /> <EventID>4648</EventID> <Version>0</Version> <Level>0</Level> <Task>12544</Task> <Opcode>0</Opcode> <Keywords>0x8020000000000000</Keywords> <TimeCreated SystemTime="2009-01-09T10:11:54.026Z" /> <EventRecordID>1544</EventRecordID> <Correlation /> <Execution ProcessID="636" ThreadID="2428" /> <Channel>Security</Channel> <Computer>Aurora</Computer> <Security /> </System> <EventData> <Data Name="SubjectUserSid">S-1-5-18</Data> <Data Name="SubjectUserName">AURORA$</Data> <Data Name="SubjectDomainName">WORKGROUP</Data> <Data Name="SubjectLogonId">0x3e7</Data> <Data Name="LogonGuid">{00000000-0000-0000-0000-000000000000}</Data> <Data Name="TargetUserName">SYSTEM</Data> <Data Name="TargetDomainName">NT AUTHORITY</Data> <Data Name="LogonGuid">{00000000-0000-0000-0000-000000000000}</Data> <Data Name="TargetServerName">localhost</Data> <Data Name="TargetInfo">localhost</Data> <Data Name="ProcessId">0x270</Data> <Data Name="ProcessName">C:\Windows\System32\services.exe</Data> <Data Name="IpAddress">-</Data> <Data Name="IpPort">-</Data> </EventData></Event> Log Name: SecuritySource: Microsoft-Windows-Security-AuditingDate: 1/9/2009 2:11:53 AMEvent ID: 4672Task Category: Special LogonLevel: InformationKeywords: Audit SuccessUser: N/AComputer: AuroraDescription:Special privileges assigned to new logon. Subject:Security ID:SYSTEMAccount Name:SYSTEMAccount Domain:NT AUTHORITYLogon ID:0x3e7 Privileges:SeAssignPrimaryTokenPrivilegeSeTcbPrivilegeSeSecurityPrivilegeSeTakeOwnershipPrivilegeSeLoadDriverPrivilegeSeBackupPrivilegeSeRestorePrivilegeSeDebugPrivilegeSeAuditPrivilegeSeSystemEnvironmentPrivilegeSeImpersonatePrivilegeEvent 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>4672</EventID> <Version>0</Version> <Level>0</Level> <Task>12548</Task> <Opcode>0</Opcode> <Keywords>0x8020000000000000</Keywords> <TimeCreated SystemTime="2009-01-09T10:11:53.823Z" /> <EventRecordID>1543</EventRecordID> <Correlation /> <Execution ProcessID="636" ThreadID="2428" /> <Channel>Security</Channel> <Computer>Aurora</Computer> <Security /> </System> <EventData> <Data Name="SubjectUserSid">S-1-5-18</Data> <Data Name="SubjectUserName">SYSTEM</Data> <Data Name="SubjectDomainName">NT AUTHORITY</Data> <Data Name="SubjectLogonId">0x3e7</Data> <Data Name="PrivilegeList">SeAssignPrimaryTokenPrivilegeSeTcbPrivilegeSeSecurityPrivilegeSeTakeOwnershipPrivilegeSeLoadDriverPrivilegeSeBackupPrivilegeSeRestorePrivilegeSeDebugPrivilegeSeAuditPrivilegeSeSystemEnvironmentPrivilegeSeImpersonatePrivilege</Data> </EventData></Event> Log Name: SecuritySource: Microsoft-Windows-Security-AuditingDate: 1/9/2009 2:11:53 AMEvent ID: 4624Task Category: LogonLevel: InformationKeywords: Audit SuccessUser: N/AComputer: AuroraDescription:An account was successfully logged on. Subject:Security ID:SYSTEMAccount Name:AURORA$Account Domain:WORKGROUPLogon ID:0x3e7 Logon Type:5 New Logon:Security ID:SYSTEMAccount Name:SYSTEMAccount Domain:NT AUTHORITYLogon ID:0x3e7Logon GUID:{00000000-0000-0000-0000-000000000000} Process Information:Process ID:0x270Process Name:C:\Windows\System32\services.exe Network Information:Workstation Name:Source Network Address:-Source Port:- Detailed Authentication Information:Logon Process:Advapi Authentication Package:NegotiateTransited Services:-Package Name (NTLM only):-Key Length:0 This event is generated when a logon session is created. It is generated on the computer that was accessed. The subject fields indicate the account on the local system which requested the logon. This is most commonly a service such as the Server service, or a local process such as Winlogon.exe or Services.exe. The logon type field indicates the kind of logon that occurred. The most common types are 2 (interactive) and 3 (network). The New Logon fields indicate the account for whom the new logon was created, i.e. the account that was logged on. The network fields indicate where a remote logon request originated. Workstation name is not always available and may be left blank in some cases. The authentication information fields provide detailed information about this specific logon request.- Logon GUID is a unique identifier that can be used to correlate this event with a KDC event.- Transited services indicate which intermediate services have participated in this logon request.- Package name indicates which sub-protocol was used among the NTLM protocols.- Key length indicates the length of the generated session key. This will be 0 if no session key was requested.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>4624</EventID> <Version>0</Version> <Level>0</Level> <Task>12544</Task> <Opcode>0</Opcode> <Keywords>0x8020000000000000</Keywords> <TimeCreated SystemTime="2009-01-09T10:11:53.823Z" /> <EventRecordID>1542</EventRecordID> <Correlation /> <Execution ProcessID="636" ThreadID="2428" /> <Channel>Security</Channel> <Computer>Aurora</Computer> <Security /> </System> <EventData> <Data Name="SubjectUserSid">S-1-5-18</Data> <Data Name="SubjectUserName">AURORA$</Data> <Data Name="SubjectDomainName">WORKGROUP</Data> <Data Name="SubjectLogonId">0x3e7</Data> <Data Name="TargetUserSid">S-1-5-18</Data> <Data Name="TargetUserName">SYSTEM</Data> <Data Name="TargetDomainName">NT AUTHORITY</Data> <Data Name="TargetLogonId">0x3e7</Data> <Data Name="LogonType">5</Data> <Data Name="LogonProcessName">Advapi </Data> <Data Name="AuthenticationPackageName">Negotiate</Data> <Data Name="WorkstationName"> </Data> <Data Name="LogonGuid">{00000000-0000-0000-0000-000000000000}</Data> <Data Name="TransmittedServices">-</Data> <Data Name="LmPackageName">-</Data> <Data Name="KeyLength">0</Data> <Data Name="ProcessId">0x270</Data> <Data Name="ProcessName">C:\Windows\System32\services.exe</Data> <Data Name="IpAddress">-</Data> <Data Name="IpPort">-</Data> </EventData></Event> Log Name: SecuritySource: Microsoft-Windows-Security-AuditingDate: 1/9/2009 2:11:53 AMEvent ID: 4648Task Category: LogonLevel: InformationKeywords: Audit SuccessUser: N/AComputer: AuroraDescription:A logon was attempted using explicit credentials. Subject:Security ID:SYSTEMAccount Name:AURORA$Account Domain:WORKGROUPLogon ID:0x3e7Logon GUID:{00000000-0000-0000-0000-000000000000} Account Whose Credentials Were Used:Account Name:SYSTEMAccount Domain:NT AUTHORITYLogon GUID:{00000000-0000-0000-0000-000000000000} Target Server:Target Server Name:localhostAdditional Information:localhost Process Information:Process ID:0x270Process Name:C:\Windows\System32\services.exe Network Information:Network Address:-Port:- This event is generated when a process attempts to log on an account by explicitly specifying that accounts credentials. This most commonly occurs in batch-type configurations such as scheduled tasks, or when using the RUNAS command.Event Xml:<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event"> <System> <Provider Name="Microsoft-Windows-Security-Auditing" Guid="{54849625-5478-4994-a5ba-3e3b0328c30d}" /> <EventID>4648</EventID> <Version>0</Version> <Level>0</Level> <Task>12544</Task> <Opcode>0</Opcode> <Keywords>0x8020000000000000</Keywords> <TimeCreated SystemTime="2009-01-09T10:11:53.823Z" /> <EventRecordID>1541</EventRecordID> <Correlation /> <Execution ProcessID="636" ThreadID="2428" /> <Channel>Security</Channel> <Computer>Aurora</Computer> <Security /> </System> <EventData> <Data Name="SubjectUserSid">S-1-5-18</Data> <Data Name="SubjectUserName">AURORA$</Data> <Data Name="SubjectDomainName">WORKGROUP</Data> <Data Name="SubjectLogonId">0x3e7</Data> <Data Name="LogonGuid">{00000000-0000-0000-0000-000000000000}</Data> <Data Name="TargetUserName">SYSTEM</Data> <Data Name="TargetDomainName">NT AUTHORITY</Data> <Data Name="LogonGuid">{00000000-0000-0000-0000-000000000000}</Data> <Data Name="TargetServerName">localhost</Data> <Data Name="TargetInfo">localhost</Data> <Data Name="ProcessId">0x270</Data> <Data Name="ProcessName">C:\Windows\System32\services.exe</Data> <Data Name="IpAddress">-</Data> <Data Name="IpPort">-</Data> </EventData></Event>

Hi zorachu99, thanks for posting here. Based on the log, it seems that this is related to S-1-5-18 which refers to "A service account that is used by the operating system". If you suspect that the issue is related to system security, I suggest you try a free online virus scan on the following site: http://safety.live.com Meanwhile, if you need more help with virus-related issues, please visit the Microsoft Virus Solution and Security Center for resources and tools to keep your PC safe and healthy. Hope this helps! Sean Zhu - MSFT

I noticed a similar special logon in my event log from Logon ID: 0x3e7. I have my computer set to automatically defragment my drives at the time the special logon occurred. You may want to check your settings by right-clicking your c:/ drive icon>select Properties>select Tools>select Defragment Now>underneath the schedule section it will say if automatic defragmentation is turned on and you can edit the schedule as well.