TROJ_TANDFUY.R

April 10, 2015
 Analysis by: RonJay Kristoffer Caragay
 ALIASES:

TrojanDownloader:Win32/Tandfuy.B (Microsoft); Backdoor.Trojan (Symantec); Trojan-Dropper.Win32.Agent.ktmr (Kaspersky); Mal/Generic-L (Sophos); Trojan.Win32.Generic!BT (Sunbelt)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Spyware

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Dropped by other malware, Downloaded from the Internet

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.

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

54,051 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

28 May 2014

Payload:

Downloads files

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.

Other System Modifications

This spyware 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 "%System%\qmgr.dll".)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\BITS
Start = "2"

(Note: The default value data of the said registry entry is "3".)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\BITS
Type = "272"

(Note: The default value data of the said registry entry is "32".)

Dropping Routine

This spyware drops the following files:

  • %Temp%\version361.dat
  • %System%\midimapbits.dll <-- also detected as TROJ_TANDFUY.R

(Note: %Temp% is the Windows temporary folder, where it usually is C:\Windows\Temp on all Windows operating system versions.. %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Download Routine

This spyware downloads the file from the following URL and renames the file when stored in the affected system:

  • http://{BLOCKED}idata.com/eng/test/jp1.php?m={random}&os={os version}&ie={ie version}
  • http://{BLOCKED}.{BLOCKED}.35.58/531.gif

It saves the files it downloads using the following names:

  • %System Root%\a.dat
  • %Temp%\image.jpg

(Note: %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.)

As of this writing, the said sites are inaccessible.

NOTES:

It connects to the following URLs to download its configuration file and checks ir for certain conditions. If the file does not meet the condition it is deleted:

  • http://update.{BLOCKED}k.net/ja523.jpg
  • http://www.{BLOCKED}i-pg.co.jp/bbs/data/update/ja523.jpg
  • http://www.{BLOCKED}oint.jp/member/img/ja523.jpg
  • http://www.{BLOCKED}e.net/ja523.jpg
  • http://{BLOCKED}te.gndot.com/ja523.jpg
  • http://{BLOCKED}data.com/images/ja523.jpg
  • http://www.yahoo.co.jp/{BLOCKED}3.jpg
  • http://www.{BLOCKED}e.com/ja523.jpg
  • http://www.{BLOCKED}an.co.kr/bbs/data/free/ja523.jpg
  • http://www.{BLOCKED}ng.jp/ja523.jpg
  • http://www.msn.com/{BLOCKED}3.jpg
  • http://www.{BLOCKED}e.com/ja523.jpg
  • http://www.{BLOCKED}o.jp/ja523.jpg
  • http://www.{BLOCKED}sn.com/ja523.jpg
  • http://www.{BLOCKED}s.com/ja523.jpg
  • http://www.{BLOCKED}nc.jp/ja523.jpg
  • http://www.{BLOCKED}ft.jp/
  • http://www.{BLOCKED}ory.com/start/ja523.jpg
  • http://www.{BLOCKED}arble.net/ja523.jpg

The configuration file may contain URL used to download a possibly malicious file. If the download is successful, it renames the file to the following and executes the downloaded file:

  • %Temp%\setupviewtmp.exe

It locates and executes the uninstaller of the following AV products:

  • AhnLab-V3
  • ESET Security
  • ESTsoft-Alyac
  • NHN Corp.-NaverVaccine
  • TrendMicro

  SOLUTION

Minimum Scan Engine:

9.750

VSAPI OPR PATTERN File:

10.871.00

VSAPI OPR PATTERN Date:

18 Jun 2014

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

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

Step 3

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 = "%System%\qmgr.dll"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\BITS
    • From: Start = "2"
      To: Start = "3"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\BITS
    • From: Type = "272"
      To: Type = "32"

Step 4

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
  • %System Root%\a.dat
  • %Temp%\image.jpg
  • %Temp%\version361.dat
  • %Temp%\setupviewtmp.exe

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_TANDFUY.R. 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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