TROJ_VBKRYPT.XEH


 ALIASES:

Mal/DownLdr-S, Mal/EncPk-CK (Sophos)

 PLATFORM:

Windows

 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:

59,392 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

04 Dec 2014

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.

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
MseUpdate = "rundll32.exe %User Temp%\midimapbits.txt,Aoout"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
MseUpdate = "rundll32.exe %User Temp%\midimapbits.txt,Aoout"

Other System Modifications

This Trojan deletes the following files:

  • %Windows%\imagebase113812.exe
  • %User Temp%\setupviewtmp.exe
  • %User Temp%\setupviewtmpxxx.exe
  • %Temp%\setupviewtmp.exe
  • %Temp%\setupviewtmpxxx.exe

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.. %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %Temp% is the Windows temporary folder, where it usually is C:\Windows\Temp on all Windows operating system versions.)

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\BITS
WOW64 = "1"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\BITS\Parameters
ServiceDll = "%System%\midimapbits.dll"

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

Dropping Routine

This Trojan drops the following files:

  • %System%\midimapbits.dll
  • %User Temp%\midimapbits.txt
  • %System Root%\a.dat
  • %User Temp%\image.jpg
  • %Temp%\image.jpg

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.. %Temp% is the Windows temporary folder, where it usually is C:\Windows\Temp on all Windows operating system versions.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://www.{BLOCKED}s.or.kr/movie/img/view.php?{random characters}
  • http://ftp.{BLOCKED}ic.com/button08.jpg?201411299
  • http://www.{BLOCKED}r.co.kr/bbs2/data/prize/button08.jpg?201411299
  • http://www.{BLOCKED}int.jp/member/img/button08.jpg?201411299
  • http://www.{BLOCKED}e.net/button08.jpg?201411299
  • http://snsdate.{BLOCKED}t.com/button08.jpg?201411299
  • http://www.{BLOCKED}ank.co.kr/images/common/button08.jpg?201411299
  • http://www.{BLOCKED}o.co.jp/button08.jpg?201411299
  • http://www.{BLOCKED}e.com/button08.jpg?201411299
  • http://www.{BLOCKED}n.co.kr/bbs/data/free/button08.jpg?201411299
  • http://www.{BLOCKED}ng.jp/button08.jpg?201411299
  • http://www.{BLOCKED}n.com/button08.jpg?201411299
  • http://www.{BLOCKED}o.jp/button08.jpg?201411299
  • http://www.{BLOCKED}sn.com/button08.jpg?201411299
  • http://www.{BLOCKED}c.jp/button08.jpg?201411299
  • http://www.{BLOCKED}y.com/start/button08.jpg?201411299
  • http://www.{BLOCKED}ble.net/button08.jpg?201411299
  • http://ftp.{BLOCKED}ic.com/navw.gif
  • {BLOCKED}5.6.203
  • {BLOCKED}35.67
  • {BLOCKED}9.222.141
  • {BLOCKED}.145.238
  • {BLOCKED}0.49.173
  • {BLOCKED}.145.169
  • {BLOCKED}35.200
  • {BLOCKED}.198.79
  • {BLOCKED}.131.112
  • {BLOCKED}.197.203
  • {BLOCKED}5.241.23
  • {BLOCKED}.102.42
  • {BLOCKED}6.66.188
  • {BLOCKED}6.66.199
  • {BLOCKED}.93.117
  • {BLOCKED}1.30.11

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.700

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 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
    • MseUpdate = "rundll32.exe %User Temp%\midimapbits.txt,Aoout"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • MseUpdate = "rundll32.exe %User Temp%\midimapbits.txt,Aoout"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\BITS
    • WOW64 = "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\SYSTEM\ControlSet001\Services\BITS\Parameters
    • From: ServiceDll = "%System%\midimapbits.dll"
      To: ServiceDll = ""{random values}""

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%\midimapbits.dll
  • %User Temp%\midimapbits.txt
  • %System Root%\a.dat
  • %User Temp%\image.jpg
  • %Temp%\image.jpg

Step 6

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

  • %Windows%\imagebase113812.exe
  • %User Temp%\setupviewtmp.exe
  • %User Temp%\setupviewtmpxxx.exe
  • %Temp%\setupviewtmp.exe
  • %Temp%\setupviewtmpxxx.exe


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