TSPY_YAKBEEX.BYZ


 PLATFORM:

Windows

 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:

799,744 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

30 Nov 2016

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.

Installation

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

  • %User Profile%\Application Data\asp.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Application = "%User Profile%\Application Data\asp.exe"

Other System Modifications

This spyware deletes the following files:

  • {malware path and file name}:zone.identifier
  • %User Profile%\New text document.txt
  • %User Profile%\Application Data\asp.exe
  • %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.188.32046
  • %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.188.32046
  • %User Profile%\v2.0.50727.42\security.config.cch.188.32171
  • %User Profile%\Application Data\asp.exe:Zone.Identifier
  • %User Profile%\Application Data\CWS_H15_VC15_11_18_2_29_1.jpg
  • %User Profile%\Application Data\CWS_H15_VC15_11_18_2_30_1.jpg
  • %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.1684.85000
  • %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.1684.85015
  • %User Profile%\v2.0.50727.42\security.config.cch.1684.85171

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

It 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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\asp

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
ESENT\Process\asp\
DEBUG

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:

  • %User Profile%\My Documents\New text document.txt

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Other Details

This spyware connects to the following possibly malicious URL:

  • 185.145.128.177

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.8

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
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ESENT\Process
    • asp
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ESENT\Process\asp
    • 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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • Application = "%User Profile%\Application Data\asp.exe"

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 this file

[ Learn More ]
There may be some 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.
  • %User Profile%\My Documents\New text document.txt

Step 7

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TSPY_YAKBEEX.BYZ. 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 8

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.

  • {malware path and file name}:zone.identifier
  • %User Profile%\New text document.txt
  • %User Profile%\Application Data\asp.exe
  • %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.188.32046
  • %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.188.32046
  • %User Profile%\v2.0.50727.42\security.config.cch.188.32171
  • %User Profile%\Application Data\asp.exe:Zone.Identifier
  • %User Profile%\Application Data\CWS_H15_VC15_11_18_2_29_1.jpg
  • %User Profile%\Application Data\CWS_H15_VC15_11_18_2_30_1.jpg
  • %Windows%\Microsoft.NET\Framework\v2.0.50727\config\security.config.cch.1684.85000
  • %Windows%\Microsoft.NET\Framework\v2.0.50727\config\enterprisesec.config.cch.1684.85015
  • %User Profile%\v2.0.50727.42\security.config.cch.1684.85171


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