ALIASES:

RDN/Generic PWS.y!b2r (McAfee); HEUR:Trojan.Win32.Generic (Kaspersky); Mal/Packer (Sophos); Trojan horse Generic_r.DZQ.dropper (AVG)

 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:

  • 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.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 44,009 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 20 Aug 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.

Installation

This Trojan creates the following folders:

  • %Program Files%\Common Files\Plugins

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)

Autostart Technique

This Trojan registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\V3Serv\Parameters

Other System Modifications

This Trojan deletes the following files:

  • %Temp%\scs13.tmp
  • %Temp%\scs19.tmp

(Note: %Temp% is the Windows Temporary folder, which is usually C:\Windows\Temp.)

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\SvcHost
V3Serv = "V3Serv,V3 Serv,VaServ mornitor for V3 AntiVirius,_CHAR(0x12)_,¹ @"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Serv
Description = "VaServ mornitor for V3 AntiVirius"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Serv
DisplayName = "V3 Serv"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Serv
ErrorControl = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Serv
Group = "Com Infrastructure"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Serv
ObjectName = "LocalSystem"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Serv
Start = "2"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Serv
Type = "1"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Serv
FailureAction = "{random values}"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Serv
ImagePath = "%SystemRoot%\system32\svchost -k V3Serv"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Serv\Parameters
ServiceDll = "%System%\V3Serv32.dll"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\V3Serv\Parameters
ServiceMain = "DebugEntry"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DataAccess
xyz = "{malware path and file name}"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DataAccess
vpn = "50.118.251.40"

Dropping Routine

This Trojan drops the following files:

  • %System%\V3Serv32.dll
  • %Program Files%\Common Files\Plugins\index.txt
  • %Program Files%\Common Files\Plugins\encrf.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://rters2.{BLOCKED}o.com/index.txt
  • http://rters2.{BLOCKED}o.com/encrf.exe
  • {BLOCKED}.155.68

It deletes itself after execution.

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 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\SYSTEM\CurrentControlSet\Services\V3Serv
    • Parameters

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 NT\CurrentVersion\SvcHost
    • V3Serv = "V3Serv,V3 Serv,VaServ mornitor for V3 AntiVirius,_CHAR(0x12)_,¹ @"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Serv
    • Description = "VaServ mornitor for V3 AntiVirius"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Serv
    • DisplayName = "V3 Serv"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Serv
    • ErrorControl = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Serv
    • Group = "Com Infrastructure"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Serv
    • ObjectName = "LocalSystem"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Serv
    • Start = "2"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Serv
    • Type = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Serv
    • FailureAction = "{random values}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Serv
    • ImagePath = "%SystemRoot%\system32\svchost -k V3Serv"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Serv\Parameters
    • ServiceDll = "%System%\V3Serv32.dll"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\V3Serv\Parameters
    • ServiceMain = "DebugEntry"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DataAccess
    • xyz = "{malware path and file name}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\DataAccess
    • vpn = "50.118.251.40"

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%\V3Serv32.dll
  • %Program Files%\Common Files\Plugins\index.txt
  • %Program Files%\Common Files\Plugins\encrf.exe

Step 6

Search and delete this folder

[ 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.
  • %Program Files%\Common Files\Plugins

Step 7

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

  • %Temp%\scs13.tmp
  • %Temp%\scs19.tmp


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