TROJ_INJECTOR.NP


 ALIASES:

VirTool:Win32/DelfInject.gen!X (Microsoft); Generic.dx!bcwt (McAfee); Backdoor.Graybird (Symantec); PAK:UPX (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan.Delf.Inject.Z (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:

242,688 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

31 May 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 Root%\ProgramData\TuvjywK\CtlouiB\ElsxjvO.exe

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

It creates the following folders:

  • %System Root%\ProgramData
  • %System Root%\ProgramData\TuvjywK
  • %System Root%\ProgramData\TuvjywK\OncfoyP
  • %System Root%\ProgramData\TuvjywK\CtlouiB
  • %System Root%\ProgramData\TuvjywK\RyunogB

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

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
ElsxjvO = "%System Root%\ProgramData\TuvjywK\CtlouiB\ElsxjvO.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\sistemanet

It adds the following registry entries:

HKEY_CURRENT_USER\Software\sistemanet
direct = "jiijehjibjhojaadjaaajaocjaadjigjaoijfhjigjaafjigjibjhdjaagjaahjaofjabajaaijge)"

HKEY_CURRENT_USER\Software\sistemanet
name1 = "jfijaohjaaejabojaofjaahjgi)"

HKEY_CURRENT_USER\Software\sistemanet
lugarjpg = "{random characters}"

HKEY_CURRENT_USER\Software\sistemanet
dir2 = "{random characters}"

HKEY_CURRENT_USER\Software\sistemanet
dir = "{random characters}"

HKEY_CURRENT_USER\Software\sistemanet
l001 = "jaaf)"

HKEY_CURRENT_USER\Software\sistemanet
aviso = "jaaejaoejaoi)"

HKEY_CURRENT_USER\Software\sistemanet
data = "jdhjec)"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
SystemCertificates\CA\Certificates\
FE622EA7B33CA46519AB39736A66B8F6E41FF157
Blob = "{random values}"

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DirectDraw\MostRecentApplication
Name = "notepad.exe"

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DirectDraw\MostRecentApplication
ID = "4117cc3"

(Note: The default value data of the said registry entry is 41107b81.)

Dropping Routine

This Trojan drops the following files:

  • %System Root%\ProgramData\TuvjywK\RyunogB\md9.bmp
  • %System Root%\ProgramData\TuvjywK\RyunogB\mdb-11-md9

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

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_CURRENT_USER\Software
    • sistemanet

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
    • ElsxjvO = "%System Root%\ProgramData\TuvjywK\CtlouiB\ElsxjvO.exe"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • direct = "jiijehjibjhojaadjaaajaocjaadjigjaoijfhjigjaafjigjibjhdjaagjaahjaofjabajaaijge)"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • name1 = "jfijaohjaaejabojaofjaahjgi)"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • lugarjpg = "{random characters}"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • dir2 = "{random characters}"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • dir = "{random characters}"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • l001 = "jaaf)"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • aviso = "jaaejaoejaoi)"
  • In HKEY_CURRENT_USER\Software\sistemanet
    • data = "jdhjec)"

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\SystemCertificates\CA\Certificates\FE622EA7B33CA46519AB39736A66B8F6E41FF157
    • From: Blob = "{random values}"
      To: Blob = ""{random values}""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication
    • From: Name = "notepad.exe"
      To: Name = ""iexplore.exe""
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DirectDraw\MostRecentApplication
    • From: ID = "4117cc3"
      To: ID = ""41107b81""

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%\ProgramData\TuvjywK\RyunogB\md9.bmp
  • %System Root%\ProgramData\TuvjywK\RyunogB\mdb-11-md9

Step 7

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %System Root%\ProgramData
  • %System Root%\ProgramData\TuvjywK
  • %System Root%\ProgramData\TuvjywK\OncfoyP
  • %System Root%\ProgramData\TuvjywK\CtlouiB
  • %System Root%\ProgramData\TuvjywK\RyunogB

Step 8

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