ALIASES:

Backdoor:Win32/Popwin.gen!E (Microsoft); BackDoor-DKA.gen.b (McAfee); Trojan Horse (Symantec); Trojan.Win32.Generic!BT (Sunbelt); Trojan.Generic.1255406 (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: 77,863 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 30 Nov 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:

  • %System%\CTFMON.EXE

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

Other System Modifications

This Trojan deletes the following files:

  • %System%\COPY20~1.BAT

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

It adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Speech

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
CTF\Assemblies

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\360Safe\
safemon
ExecAccess = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\360Safe\
safemon
SiteAccess = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\360Safe\
safemon
MonAccess = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\360Safe\
safemon
LeakAccess = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\360Safe\
safemon
UDiskAccess = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\360Safe\
safemon
ARPAccess = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT
ReportBootOk = "1"

HKEY_CURRENT_USER\Software\Microsoft\
CTF\LangBar
ExtraIconsOnMinimized = "1"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
PCHealth\ErrorReporting
DoReport = "0"

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
PCHealth\ErrorReporting
ShowUI = "0"

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
ctfmon.exe = "%System%\ctfmon.exe"

(Note: The default value data of the said registry entry is %Windows%\system32\ctfmon.exe.)

HKEY_CURRENT_USER\Software\Microsoft\
CTF\Sapilayr
ProfileInitialized = "0"

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

HKEY_CURRENT_USER\Software\Microsoft\
CTF\Sapilayr
ProfileInitialized = "1"

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

HKEY_CURRENT_USER\Software\Microsoft\
CTF\TIP\{DCBD6FA8-032F-11D3-B5B1-00C04FC324A1}\
LanguageProfile\0x00000409\{09EA4E4B-46CE-4469-B450-0DE76A435BBB}
Enable = "0"

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

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\ERSvc\Parameters

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\ERSvc\Security

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\ERSvc\Enum

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\ERSvc

Dropping Routine

This Trojan drops the following files:

  • %System%\copy2090000.bat
  • %System Root%\iexpe.exe
  • %System%\Com\ie.exe
  • %System%\CFTMON.EXE

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://2008.{BLOCKED}t.com/2008//user/setup1468.txt
  • http://2008.{BLOCKED}t.com/2008//update.txt

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.300

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_CURRENT_USER\Software\Microsoft
    • Speech
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\CTF
    • Assemblies

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\360Safe\safemon
    • ExecAccess = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\360Safe\safemon
    • SiteAccess = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\360Safe\safemon
    • MonAccess = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\360Safe\safemon
    • LeakAccess = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\360Safe\safemon
    • UDiskAccess = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\360Safe\safemon
    • ARPAccess = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT
    • ReportBootOk = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\CTF\LangBar
    • ExtraIconsOnMinimized = "1"

Step 4

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\PCHealth\ErrorReporting
    • From: DoReport = "0"
      To: DoReport = ""1""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\PCHealth\ErrorReporting
    • From: ShowUI = "0"
      To: ShowUI = ""1""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • From: ctfmon.exe = "%System%\ctfmon.exe"
      To: ctfmon.exe = ""%Windows%\system32\ctfmon.exe""
  • In HKEY_CURRENT_USER\Software\Microsoft\CTF\Sapilayr
    • From: ProfileInitialized = "0"
      To: ProfileInitialized = ""1""
  • In HKEY_CURRENT_USER\Software\Microsoft\CTF\Sapilayr
    • From: ProfileInitialized = "1"
      To: ProfileInitialized = ""1""
  • In HKEY_CURRENT_USER\Software\Microsoft\CTF\TIP\{DCBD6FA8-032F-11D3-B5B1-00C04FC324A1}\LanguageProfile\0x00000409\{09EA4E4B-46CE-4469-B450-0DE76A435BBB}
    • From: Enable = "0"
      To: Enable = ""1""

Step 5

Search and delete these components

[ Learn More ]
There may be some components 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%\copy2090000.bat
  • %System Root%\iexpe.exe
  • %System%\Com\ie.exe
  • %System%\CFTMON.EXE

Step 6

Scan your computer with your Trend Micro product to delete files detected as TROJ_DLOADER.OGX. 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.

Step 7

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %System%\COPY20~1.BAT

Step 8

Restore these deleted registry keys/values from backup

*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\ERSvc
    • Parameters
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\ERSvc
    • Security
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\ERSvc
    • Enum
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
    • ERSvc


Did this description help? Tell us how we did.