ALIASES:

Backdoor:Win32/IRCbot.FY (Microsoft); Exploit-MS04-011.gen (McAfee); W32.Spybot.Worm (Symantec); Net-Worm.Win32.Kolabc.heg (Kaspersky); BehavesLike.Win32.Malware.eah (mx-v) (Sunbelt); Dropped:Generic.Mydoom.0EFCAEEB (FSecure)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This Trojan 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: 4,808,704 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 03 Jul 2012

Arrival Details

This Trojan 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 Trojan drops the following copies of itself into the affected system:

  • %Windows%\Fonts\uninstall_.exe

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\Software\Policies\
Microsoft\Windows NT\Windows File Protection

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\MRT

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Shell Extensions
msgone = "{malware path and file name}"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control
WaitToKillServiceT = "5000"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
MaxUserPort = "fffe"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
TcpTimedWaitDelay = "1e"

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

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
Tcp1323Opts = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
GlobalMaxTcpWindowSize = "3ebc"

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

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

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

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

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

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
LargeBufferSize = "c8"

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

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
TcpNumConnections = "fffffe"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows\WindowsUpdate
DoNotAllowXPSP2 = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\AFD\Parameters
DisableRawSecurity = "1"

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

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

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\lanmanserver\parameters
SizReqBuf = "4"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows NT\Windows File Protection
SFCDisable = "ffffff9d"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\Windows NT\Windows File Protection
SFCScan = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\lanmanserver\parameters
AutoShareServer = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\lanmanserver\parameters
AutoShareWks = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
EnableFirewall = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DoNotAllowExceptions = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DisableNotifications = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile
EnableFirewall = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile
DoNotAllowExceptions = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile
DisableNotifications = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Policies\
Microsoft\MRT
DontReportInfectionInformation = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
uninstall_.exe = "uninstall_.exe:*:Enabled:SYSTEM"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile\AuthorizedApplications\
List
uninstall_.exe = "uninstall_.exe:*:Enabled:SYSTEM"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
445:TCP = "445:TCP:LocalSubNet:Enabled:@xpsp2res.dll,-22005"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
139:TCP = "139:TCP:LocalSubNet:Enabled:@xpsp2res.dll,-22004"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
1013:TCP = "1013:TCP:*:Enabled:BS"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
9999:TCP = "9999:TCP:*:Enabled:PORT1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
9991:TCP = "9991:TCP:*:Enabled:PORT2"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%Windows%\Fonts\uninstall_.exe = "%Windows%\Fonts\uninstall_.exe:*:Enabled:workstation"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Tcpip\Parameters
TcpWindowSize = "3ebc"

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

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

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\
Services\NetBT\Parameters
TransportBindName = "\Device"

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusDisableNotify = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
AntiVirusOverride = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallDisableNotify = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
FirewallOverride = "1"

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

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\Policies\Microsoft\Windows NT
    • Windows File Protection
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft
    • MRT

Step 3

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\Shell Extensions
    • msgone = "{malware path and file name}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control
    • WaitToKillServiceT = "5000"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • MaxUserPort = "fffe"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • TcpTimedWaitDelay = "1e"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • StrictTimeWaitSeqCheck = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • Tcp1323Opts = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • GlobalMaxTcpWindowSize = "3ebc"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • EnablePMTUDiscovery = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • EnablePMTUBHDetect = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • SackOpts = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • DefaultTTL = "4"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • TcpMaxDupAcks = "2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • LargeBufferSize = "c8"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • AllowUserRawAccess = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • TcpNumConnections = "fffffe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate
    • DoNotAllowXPSP2 = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\AFD\Parameters
    • DisableRawSecurity = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
    • MaxConnectionsPer1_0Server = "fffe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
    • MaxConnectionsPerServer = "fffe"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\lanmanserver\parameters
    • SizReqBuf = "4"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\Windows File Protection
    • SFCDisable = "ffffff9d"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows NT\Windows File Protection
    • SFCScan = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\lanmanserver\parameters
    • AutoShareServer = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\lanmanserver\parameters
    • AutoShareWks = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
    • EnableFirewall = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
    • DoNotAllowExceptions = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
    • DisableNotifications = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile
    • EnableFirewall = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile
    • DoNotAllowExceptions = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile
    • DisableNotifications = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\MRT
    • DontReportInfectionInformation = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • uninstall_.exe = "uninstall_.exe:*:Enabled:SYSTEM"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile\AuthorizedApplications\List
    • uninstall_.exe = "uninstall_.exe:*:Enabled:SYSTEM"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
    • 445:TCP = "445:TCP:LocalSubNet:Enabled:@xpsp2res.dll,-22005"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
    • 139:TCP = "139:TCP:LocalSubNet:Enabled:@xpsp2res.dll,-22004"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
    • 1013:TCP = "1013:TCP:*:Enabled:BS"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
    • 9999:TCP = "9999:TCP:*:Enabled:PORT1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
    • 9991:TCP = "9991:TCP:*:Enabled:PORT2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %Windows%\Fonts\uninstall_.exe = "%Windows%\Fonts\uninstall_.exe:*:Enabled:workstation"

Step 4

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\SYSTEM\ControlSet001\Services\Tcpip\Parameters
    • From: TcpWindowSize = "3ebc"
      To: TcpWindowSize = ""faf0""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Lsa
    • restrictanonymous = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole
    • From: EnableDCOM = "N"
      To: EnableDCOM = ""Y""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\NetBT\Parameters
    • From: TransportBindName = "\Device"
      To: TransportBindName = ""\Device\""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • AntiVirusDisableNotify = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • AntiVirusOverride = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • FirewallDisableNotify = "1"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • FirewallOverride = "1"

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_AGENT_031131.TOMB. 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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