TROJ_CRILOCK.YMX


 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:

3,776,512 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

17 Jun 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 drops the following copies of itself into the affected system:

  • %Application Data%\winrar.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

It creates the following folders:

  • %User Profile%\Application Data\TEMP

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
winrar = "%Application Data%\winrar.exe"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Licenses

HKEY_CLASSES_ROOT\CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}\InprocServer32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}\MiscStatus

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}\MiscStatus\
1

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}\ProgID

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}\Programmable

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}\ToolboxBitmap32

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}\TypeLib

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}\Version

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}\VersionIndependentProgID

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Licenses
{R7C0DB872A3F777C0} = "{random values}"

HKEY_CURRENT_USER\Software\Licenses
{K7C0DB872A3F777C0} = "{random values}"

HKEY_LOCAL_MACHINE\SOFTWARE\Classes\
CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}\InprocServer32
ThreadingModel = "Apartment"

HKEY_CURRENT_USER\Software\Licenses
{I7B4ED451FFFFFFFF} = "{random values}"

HKEY_CURRENT_USER\Software\Licenses
{07B4ED451FFFFFFFF} = "{random values}"

HKEY_CURRENT_USER\Software
winrar = "1"

HKEY_CURRENT_USER\Software
winrar = "2"

HKEY_CURRENT_USER\Software
winrar = "3"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
RFC1156Agent\CurrentVersion\Parameters
TrapPollTimeMilliSecs = "3a98"

(Note: The default value data of the said registry entry is 3a98.)

HKEY_CURRENT_USER\Control Panel\Desktop
Wallpaper = "%User Profile%\My Documents\ttt.jpg"

(Note: The default value data of the said registry entry is %Windows%\web\wallpaper\Bliss.bmp.)

HKEY_CURRENT_USER\Control Panel\Desktop
TileWallpaper = "0"

(Note: The default value data of the said registry entry is 0.)

Dropping Routine

This Trojan drops the following files:

  • %User Profile%\TEMP\RAIDTest
  • %Application Data%\winrar.rar
  • %User Profile%\My Documents\ttt.jpg
  • mmm.bat

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

Other Details

This Trojan 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_CURRENT_USER\Software
    • Licenses
  • In HKEY_CLASSES_ROOT\CLSID
    • {5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}
    • InprocServer32
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}
    • MiscStatus
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}\MiscStatus
    • 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}
    • ProgID
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}
    • Programmable
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}
    • ToolboxBitmap32
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}
    • TypeLib
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}
    • Version
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}
    • VersionIndependentProgID

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • winrar = "%Application Data%\winrar.exe"
  • In HKEY_CURRENT_USER\Software\Licenses
    • {R7C0DB872A3F777C0} = "{random values}"
  • In HKEY_CURRENT_USER\Software\Licenses
    • {K7C0DB872A3F777C0} = "{random values}"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Classes\CLSID\{5E4EBB7F-5E4E-BB7F-5E4E-BB7F5E4EBB7F}\InprocServer32
    • ThreadingModel = "Apartment"
  • In HKEY_CURRENT_USER\Software\Licenses
    • {I7B4ED451FFFFFFFF} = "{random values}"
  • In HKEY_CURRENT_USER\Software\Licenses
    • {07B4ED451FFFFFFFF} = "{random values}"
  • In HKEY_CURRENT_USER\Software
    • winrar = "1"
  • In HKEY_CURRENT_USER\Software
    • winrar = "2"
  • In HKEY_CURRENT_USER\Software
    • winrar = "3"

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\SOFTWARE\Microsoft\RFC1156Agent\CurrentVersion\Parameters
    • From: TrapPollTimeMilliSecs = "3a98"
      To: TrapPollTimeMilliSecs = ""3a98""
  • In HKEY_CURRENT_USER\Control Panel\Desktop
    • From: Wallpaper = "%User Profile%\My Documents\ttt.jpg"
      To: Wallpaper = ""%Windows%\web\wallpaper\Bliss.bmp""
  • In HKEY_CURRENT_USER\Control Panel\Desktop
    • From: TileWallpaper = "0"
      To: TileWallpaper = ""0""

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.
  • %User Profile%\TEMP\RAIDTest
  • %Application Data%\winrar.rar
  • %User Profile%\My Documents\ttt.jpg
  • mmm.bat

Step 7

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.
  • %User Profile%\Application Data\TEMP

Step 8

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