ALIASES:

RiskTool.Win32.Deleter.i (Kaspersky); Found Win32/DH{IA9MLiIjJWQANjU} (AVG)

 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: 1,053,184 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 06 Jun 2013

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
{malware file name} = "{malware path and file name}"

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\ijqljcq

Other System Modifications

This Trojan adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
EnableLUA = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\ijqljcq
ImagePath = "system32\drivers\pxvii.sys"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\ijqljcq
Start = "0"

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

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

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\ijqljcq
yyeunhxz = "\??\%Program Files%\exzgrn.txt"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\ijqljcq
zabqttjc = "%Windows%"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\ijqljcq
jgrod = "bab"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\ijqljcq
Group = "focd"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\ServiceGroupOrder
List = "{random characters}"

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

Dropping Routine

This Trojan drops the following files:

  • %System Root%\Flash.exe
  • %System Root%\Plg.txt
  • %Program Files%\exzgrn.txt
  • %System%\drivers\pxvii.sys
  • %System Root%\zip.exe
  • %System Root%\cleanup.bat
  • %System Root%\cleanup.exe

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %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).. %System% is the Windows system folder, which is usually C:\Windows\System32.)

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine: 9.300

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
    • ijqljcq

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
    • {malware file name} = "{malware path and file name}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
    • Cleanup = "%System Root%\cleanup.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
    • EnableLUA = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\ijqljcq
    • ImagePath = "system32\drivers\pxvii.sys"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\ijqljcq
    • Start = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\ijqljcq
    • Type = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\ijqljcq
    • ErrorControl = "1"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\ijqljcq
    • yyeunhxz = "\??\%Program Files%\exzgrn.txt"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\ijqljcq
    • zabqttjc = "%Windows%"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\ijqljcq
    • jgrod = "bab"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\ijqljcq
    • Group = "focd"

Step 5

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\Control\ServiceGroupOrder
    • From: List = "{random characters}"
      To: List = ""{random values}""

Step 6

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 Root%\Flash.exe
  • %System Root%\Plg.txt
  • %Program Files%\exzgrn.txt
  • %System%\drivers\pxvii.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_KILLAV.AUQ. 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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