PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

 OVERALL RISK RATING:
 REPORTED INFECTION:
 SYSTEM IMPACT RATING:
 INFORMATION EXPOSURE:

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This spyware 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: 838,656 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 13 Dec 2013

Arrival Details

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

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
NetworkNotifyer = "{malware path and file name}"

Other System Modifications

This spyware adds the following registry keys:

hkey_local_machine\software\microsoft\
esent\process\{malware file name}

hkey_local_machine\software\microsoft\
esent\process\{malware file name}\
debug

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Notepad
persistentLocalizedName = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ActiveModifiedTheme = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Shell Folders
DefaultCompressedRecord = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Notepad
lineLoadedQuick = "DNhc/Ya+fFsuvn2EQ7dKCuIe4SHT4tkJK9zHn1OFJV0Vhz+i68B9KapKig4J7MEJAQ=="

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
SizeCompletedValid = "DNhc/Ya+fFsuvn2EQ7dKCuIe4SHT4tkJK9zHn1OFJV0Vhz+i68B9KapKig4J7MEJAQ=="

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Shell Folders
RecordModifiedMax = "DNhc/Ya+fFsuvn2EQ7dKCuIe4SHT4tkJK9zHn1OFJV0Vhz+i68B9KapKig4J7MEJAQ=="

HKEY_CURRENT_USER\Software\Microsoft\
Notepad
recordEnabledCheck = "5"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
StyleModifiedPrev = "5"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Shell Folders
UrlEnabledUse = "5"

HKEY_CURRENT_USER\Software\Microsoft\
Notepad
platformCompressedValid = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
InfoPlayedCurrent = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Shell Folders
FlagsModifiedValid = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Notepad
dBSavedUse = "{random values}"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
EventMessageFile = "%System%\esent.dll"

(Note: The default value data of the said registry entry is {random values}.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
CategoryMessageFile = "%System%\esent.dll"

(Note: The default value data of the said registry entry is {random values}.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
CategoryCount = "1"

(Note: The default value data of the said registry entry is 10.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Eventlog\Application\
ESENT
TypesSupported = "7"

(Note: The default value data of the said registry entry is 7.)

Dropping Routine

This spyware drops the following files:

  • %System Root%\tmp.exe
  • %System%\Packet.dll
  • %System%\wpcap.dll
  • %System%\drivers\npf.sys

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

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.300

Step 1

Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.

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\esent\process
    • {malware file name}
  • In hkey_local_machine\software\microsoft\esent\process\{malware file name}
    • debug

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
    • NetworkNotifyer = "{malware path and file name}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Notepad
    • persistentLocalizedName = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • ActiveModifiedTheme = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders
    • DefaultCompressedRecord = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Notepad
    • lineLoadedQuick = "DNhc/Ya+fFsuvn2EQ7dKCuIe4SHT4tkJK9zHn1OFJV0Vhz+i68B9KapKig4J7MEJAQ=="
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • SizeCompletedValid = "DNhc/Ya+fFsuvn2EQ7dKCuIe4SHT4tkJK9zHn1OFJV0Vhz+i68B9KapKig4J7MEJAQ=="
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders
    • RecordModifiedMax = "DNhc/Ya+fFsuvn2EQ7dKCuIe4SHT4tkJK9zHn1OFJV0Vhz+i68B9KapKig4J7MEJAQ=="
  • In HKEY_CURRENT_USER\Software\Microsoft\Notepad
    • recordEnabledCheck = "5"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • StyleModifiedPrev = "5"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders
    • UrlEnabledUse = "5"
  • In HKEY_CURRENT_USER\Software\Microsoft\Notepad
    • platformCompressedValid = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • InfoPlayedCurrent = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders
    • FlagsModifiedValid = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Notepad
    • dBSavedUse = "{random values}"

Step 5

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\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
    • From: EventMessageFile = "%System%\esent.dll"
      To: EventMessageFile = ""{random values}""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
    • From: CategoryMessageFile = "%System%\esent.dll"
      To: CategoryMessageFile = ""{random values}""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
    • From: CategoryCount = "1"
      To: CategoryCount = ""10""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Eventlog\Application\ESENT
    • From: TypesSupported = "7"
      To: TypesSupported = ""7""

Step 6

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 Root%\tmp.exe
  • %System%\Packet.dll
  • %System%\wpcap.dll
  • %System%\drivers\npf.sys

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_TEPFER.CKY. 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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