PE_VIRUT.XV


 ALIASES:

Backdoor:Win32/Rbot (Microsoft); W32/Virut.gen (McAfee); W32.Virut.W (Symantec); Virus.Win32.Virut.y (Kaspersky); Virus.Win32.Virut.a (v) (Sunbelt); Backdoor.Agent.ZJI (FSecure)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 REPORTED INFECTION:

  • Threat Type: File infector

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This file infector arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

  TECHNICAL DETAILS

File Size:

926,208 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

02 Jun 2012

Arrival Details

This file infector arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This file infector drops the following copies of itself into the affected system:

  • %System%\upds.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

Autostart Technique

This file infector adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Windows System Update Tools = "upds.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunServices
Windows System Update Tools = "upds.exe"

Other System Modifications

This file infector adds the following registry keys:

HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\RunServices

HKEY_CURRENT_USER\Software\Microsoft\
OLE

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\SecurityProviders\SCHANNEL\
Protocols\PCT1.0\Server

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
OLE
Windows System Update Tools = "upds.exe"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%System%\upds.exe = "%System%\upds.exe:*:Enabled:Windows System Update Tools"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Ole
EnableRemoteConnect = "N"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\SecurityProviders\SCHANNEL\
Protocols\PCT1.0\Server
Enabled = "{random values}"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\lanmanserver\parameters
AutoShareWks = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\lanmanserver\parameters
AutoShareServer = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
AllowUnqualifiedQuery = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
PrioritizeRecordData = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
TCP1320Opts = "3"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
KeepAliveTime = "2328"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
BcastQueryTimeout = "2ee"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
BcastNameQueryCount = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
CacheTimeout = "ea6"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
Size/Small/Medium/Large = "3"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
LargeBufferSize = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
SynAckProtect = "2"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
PerformRouterDiscovery = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
EnablePMTUBHDetect = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
FastSendDatagramThreshold = "4"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
StandardAddressLength = "18"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
DefaultReceiveWindow = "4"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
DefaultSendWindow = "4"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
BufferMultiplier = "2"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
PriorityBoost = "2"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
IrpStackSize = "4"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
IgnorePushBitOnReceives = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
DisableAddressSharing = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
AllowUserRawAccess = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
DisableRawSecurity = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
DynamicBacklogGrowthDelta = "32"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
FastCopyReceiveThreshold = "4"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
LargeBufferListDepth = "a"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
MaxActiveTransmitFileCount = "2"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
MaxFastTransmit = "4"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
OverheadChargeGranularity = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
SmallBufferListDepth = "2"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
SmallerBufferSize = "8"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
TransmitWorker = "2"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
DNSQueryTimeouts = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
DefaultRegistrationTTL = "14"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
DisableReplaceAddressesInConflicts = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
DisableReverseAddressRegistrations = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
UpdateSecurityLevel = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
DisjointNameSpace = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
QueryIpMatching = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
NoNameReleaseOnDemand = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
EnableDeadGWDetect = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
EnableFastRouteLookup = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
MaxFreeTcbs = "7d"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
MaxHashTableSize = "8"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
SackOpts = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
Tcp1323Opts = "3"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
TcpMaxDupAcks = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
TcpRecvSegmentSize = "585"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
TcpSendSegmentSize = "585"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
DefaultTTL = "3"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
TcpMaxHalfOpen = "4b"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
TcpMaxHalfOpenRetried = "5"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
TcpTimedWaitDelay = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
MaxNormLookupMemory = "3d4"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
FFPControlFlags = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
FFPFastForwardingCacheSize = "3d4"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
MaxForwardBufferMemory = "19df7"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
MaxFreeTWTcbs = "7d"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
GlobalMaxTcpWindowSize = "7d2"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
EnablePMTUDiscovery = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
ForwardBufferMemory = "19df7"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
MaxConnectionsPer1_0Server = "5"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
MaxConnectionsPerServer = "5"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Ole
EnableDCOM = "N"

(Note: The default value data of the said registry entry is Y.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\Lsa
restrictanonymous = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess
Start = "4"

(Note: The default value data of the said registry entry is 2.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\wuauserv
Start = "4"

(Note: The default value data of the said registry entry is 2.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\wscsvc
Start = "4"

(Note: The default value data of the said registry entry is 2.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
ForwardBroadcasts = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
IPEnableRouter = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
UseDomainNameDevolution = "1"

(Note: The default value data of the said registry entry is 1.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
EnableICMPRedirect = "0"

(Note: The default value data of the said registry entry is 1.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
DeadGWDetectDefault = "1"

(Note: The default value data of the said registry entry is 1.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
DontAddDefaultGatewayDefault = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
EnableSecurityFilters = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
TcpWindowSize = "7d2"

(Note: The default value data of the said registry entry is faf0.)

Dropping Routine

This file infector drops the following files:

  • %System Root%\a.bat
  • %User Temp%\1.reg

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Restart in Safe Mode

[ Learn More ]

Step 3

Delete this registry key

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion
    • RunServices
  • In HKEY_CURRENT_USER\Software\Microsoft
    • OLE
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\PCT1.0
    • Server

Step 4

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Windows System Update Tools = "upds.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunServices
    • Windows System Update Tools = "upds.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\OLE
    • Windows System Update Tools = "upds.exe"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %System%\upds.exe = "%System%\upds.exe:*:Enabled:Windows System Update Tools"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole
    • EnableRemoteConnect = "N"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\SecurityProviders\SCHANNEL\Protocols\PCT1.0\Server
    • Enabled = "{random values}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\lanmanserver\parameters
    • AutoShareWks = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\lanmanserver\parameters
    • AutoShareServer = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • AllowUnqualifiedQuery = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • PrioritizeRecordData = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • TCP1320Opts = "3"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • KeepAliveTime = "2328"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • BcastQueryTimeout = "2ee"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • BcastNameQueryCount = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • CacheTimeout = "ea6"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • Size/Small/Medium/Large = "3"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • LargeBufferSize = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • SynAckProtect = "2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • PerformRouterDiscovery = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • EnablePMTUBHDetect = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • FastSendDatagramThreshold = "4"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • StandardAddressLength = "18"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • DefaultReceiveWindow = "4"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • DefaultSendWindow = "4"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • BufferMultiplier = "2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • PriorityBoost = "2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • IrpStackSize = "4"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • IgnorePushBitOnReceives = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • DisableAddressSharing = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • AllowUserRawAccess = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • DisableRawSecurity = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • DynamicBacklogGrowthDelta = "32"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • FastCopyReceiveThreshold = "4"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • LargeBufferListDepth = "a"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • MaxActiveTransmitFileCount = "2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • MaxFastTransmit = "4"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • OverheadChargeGranularity = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • SmallBufferListDepth = "2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • SmallerBufferSize = "8"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • TransmitWorker = "2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • DNSQueryTimeouts = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • DefaultRegistrationTTL = "14"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • DisableReplaceAddressesInConflicts = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • DisableReverseAddressRegistrations = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • UpdateSecurityLevel = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • DisjointNameSpace = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • QueryIpMatching = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • NoNameReleaseOnDemand = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • EnableDeadGWDetect = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • EnableFastRouteLookup = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • MaxFreeTcbs = "7d"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • MaxHashTableSize = "8"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • SackOpts = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • Tcp1323Opts = "3"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • TcpMaxDupAcks = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • TcpRecvSegmentSize = "585"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • TcpSendSegmentSize = "585"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • DefaultTTL = "3"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • TcpMaxHalfOpen = "4b"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • TcpMaxHalfOpenRetried = "5"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • TcpTimedWaitDelay = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • MaxNormLookupMemory = "3d4"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • FFPControlFlags = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • FFPFastForwardingCacheSize = "3d4"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • MaxForwardBufferMemory = "19df7"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • MaxFreeTWTcbs = "7d"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • GlobalMaxTcpWindowSize = "7d2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • EnablePMTUDiscovery = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • ForwardBufferMemory = "19df7"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
    • MaxConnectionsPer1_0Server = "5"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
    • MaxConnectionsPerServer = "5"

Step 5

Restore this modified registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole
    • From: EnableDCOM = "N"
      To: EnableDCOM = ""Y""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Lsa
    • restrictanonymous = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess
    • From: Start = "4"
      To: Start = ""2""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\wuauserv
    • From: Start = "4"
      To: Start = ""2""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\wscsvc
    • From: Start = "4"
      To: Start = ""2""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • ForwardBroadcasts = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • IPEnableRouter = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • From: UseDomainNameDevolution = "1"
      To: UseDomainNameDevolution = ""1""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • From: EnableICMPRedirect = "0"
      To: EnableICMPRedirect = ""1""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • From: DeadGWDetectDefault = "1"
      To: DeadGWDetectDefault = ""1""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • DontAddDefaultGatewayDefault = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • EnableSecurityFilters = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • From: TcpWindowSize = "7d2"
      To: TcpWindowSize = ""faf0""

Step 6

Search and delete these files

[ Learn More ]
There may be some component files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %System Root%\a.bat
  • %User Temp%\1.reg

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as PE_VIRUT.XV. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


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