ALIASES:

TrojanSpy:Win32/Mafod!rts (Microsoft); [000bac28.EXE]:Generic.dx!upy (McAfee); Trojan.Win32.Delf.agyt, Trojan.Win32.Delf.agyt, Trojan.Win32.Delf.agyt (Kaspersky); Trojan.Win32.Generic.pak!cobra (Sunbelt); MemScan:Trojan.Generic.5052058 (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: 6,655,433 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 12 Nov 2011

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:

  • %Application Data%\Avast.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Windows\Profiles\{user name}\Application Data on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Application Data on Windows NT, and C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003.)

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
AVG Internet Security = "%Application Data%\Avast.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\RunOnce
Cleanup = "%System Root%\cleanup.exe"

It 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\vvbqp

Other System Modifications

This Trojan adds the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\vvbqp
ImagePath = "system32\drivers\zkqz.sys"

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

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

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\vvbqp
jdtw = "\??\%Windows%\tyuabe.txt"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\vvbqp
qmvmerm = "%Windows%"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\vvbqp
snlvw = "7597"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\vvbqp
Group = "mwbl"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\ServiceGroupOrder
List = ""mwbl,System Reserved,Boot Bus Extender,System Bus Extender,SCSI miniport,Port,Primary Disk,SCSI Class,SCSI CDROM Class,FSFilter Infrastructure,FSFilter System,FSFilter Bottom,FSFilter Copy Protection,FSFilter Security Enhancer,FSFilter Open File,FSFilter Physical Quota Management,FSFilter Encryption,FSFilter Compression,FSFilter HSM,FSFilter Cluster File System,FSFilter System Recovery,FSFilter Quota Management,FSFilter Content Screener,FSFilter Continuous Backup,FSFilter Replication,FSFilter Anti-Virus,FSFilter Undelete,FSFilter Activity Monitor,FSFilter Top,Filter,Boot File System,Base,Pointer Port,Keyboard Port,Pointer Class,Keyboard Class,Video Init,Video,Video Save,File System,Event Log,Streams Drivers,NDIS Wrapper,COM Infrastructure,UIGroup,LocalValidation,PlugPlay,PNP_TDI,NDIS,TDI,NetBIOSGroup,ShellSvcGroup,SchedulerGroup,SpoolerGroup,AudioGroup,SmartCardGroup,NetworkProvider,RemoteValidation,NetDDEGroup,Parallel arbitrator,Extended Base,PCI Configuration,MØî1_CHAR(0x01)_Øî1_CHAR(0x01)_p_CHAR(0x02)_"

(Note: The default value data of the said registry entry is System Reserved.)

Dropping Routine

This Trojan drops the following files:

  • %Windows%\XcoderX_KL_1
  • %System Root%\XcoderX.exe
  • %System Root%\TITI.EXE
  • %System Root%\t.txt
  • %Windows%\tyuabe.txt
  • %System%\drivers\zkqz.sys
  • %System Root%\zip.exe
  • %System Root%\cleanup.bat
  • %System Root%\cleanup.exe

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

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_LOCAL_MACHINE\System\CurrentControlSet\Services
    • vvbqp

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\CurrentVersion\Run
    • AVG Internet Security = "%Application Data%\Avast.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
    • Cleanup = "%System Root%\cleanup.exe"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\vvbqp
    • ImagePath = "system32\drivers\zkqz.sys"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\vvbqp
    • Type = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\vvbqp
    • ErrorControl = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\vvbqp
    • jdtw = "\??\%Windows%\tyuabe.txt"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\vvbqp
    • qmvmerm = "%Windows%"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\vvbqp
    • snlvw = "7597"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\vvbqp
    • Group = "mwbl"

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\SYSTEM\ControlSet001\Control\ServiceGroupOrder
    • From: List = ""mwbl,System Reserved,Boot Bus Extender,System Bus Extender,SCSI miniport,Port,Primary Disk,SCSI Class,SCSI CDROM Class,FSFilter Infrastructure,FSFilter System,FSFilter Bottom,FSFilter Copy Protection,FSFilter Security Enhancer,FSFilter Open File,FSFilter Physical Quota Management,FSFilter Encryption,FSFilter Compression,FSFilter HSM,FSFilter Cluster File System,FSFilter System Recovery,FSFilter Quota Management,FSFilter Content Screener,FSFilter Continuous Backup,FSFilter Replication,FSFilter Anti-Virus,FSFilter Undelete,FSFilter Activity Monitor,FSFilter Top,Filter,Boot File System,Base,Pointer Port,Keyboard Port,Pointer Class,Keyboard Class,Video Init,Video,Video Save,File System,Event Log,Streams Drivers,NDIS Wrapper,COM Infrastructure,UIGroup,LocalValidation,PlugPlay,PNP_TDI,NDIS,TDI,NetBIOSGroup,ShellSvcGroup,SchedulerGroup,SpoolerGroup,AudioGroup,SmartCardGroup,NetworkProvider,RemoteValidation,NetDDEGroup,Parallel arbitrator,Extended Base,PCI Configuration,MØî1_CHAR(0x01)_Øî1_CHAR(0x01)_p_CHAR(0x02)_"
      To: List = "System Reserved"

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.
  • %Windows%\XcoderX_KL_1
  • %System Root%\XcoderX.exe
  • %System Root%\TITI.EXE
  • %System Root%\t.txt
  • %Windows%\tyuabe.txt
  • %System%\drivers\zkqz.sys
  • %System Root%\zip.exe
  • %System Root%\cleanup.bat
  • %System Root%\cleanup.exe

Step 7

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


Did this description help? Tell us how we did.