WORM_OTORUN.SMXY

November 30, 2013

Analysis by: Marfel Tiamzon

PLATFORM:

Windows 2000, XP, Server 2003

OVERALL RISK RATING:

DAMAGE POTENTIAL:

DISTRIBUTION POTENTIAL:

REPORTED INFECTION:

Threat Type: Worm
Destructiveness: No
Encrypted: Yes
In the wild: Yes

OVERVIEW

This worm arrives via removable drives. It arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

It drops copies of itself in removable drives. These dropped copies use the names of the folders located on the said drives for their file names. It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

TECHNICAL DETAILS

File Size: Varies

File Type: EXE

Memory Resident: Yes

Arrival Details

This worm arrives via removable drives.

It 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 worm drops the following copies of itself into the affected system:

%System Root%\RECYCLER\{SID}\WinSysApp.exe
%Program Files%\Windows\Common Files\Commgr.exe
%Program Files%\Windows Alerter\WinAlert.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).)

It creates the following folders:

%System Root%\RECYCLER
%System Root%\RECYCLER\{SID}

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

It injects threads into the following normal process(es):

Explorer.exe

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
WindowMessenger = %System Root%\RECYCLER\{SID}\WinSysApp.exe

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Windows Alerter = %Program Files%\Windows Alerter\WinAlert.exe

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Windows Common Files Manager = %Program Files%\Windows\Common Files\Commgr.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
WindowMessenger = %System Root%\RECYCLER\{SID}\WinSysApp.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Windows Alerter = %Program Files%\Windows Alerter\WinAlert.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Windows Common Files Manager = %Program Files%\Windows\Common Files\Commgr.exe

Other System Modifications

This worm modifies the following registry entries to hide files with Hidden attributes:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = 2

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
HideFileExt = 1

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
SuperHidden = 0

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = 0

(Note: The default value data of the said registry entry is 1.)

Propagation

This worm drops the following copy(ies) of itself in all removable drives:

YoIgDnR.exe

It drops copies of itself in removable drives. These dropped copies use the names of the folders located on the said drives for their file names.

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

[Autorun]
Open=RECYCLER\YoIgDnR.exe
Explore=RECYCLER\YoIgDnR.exe
AutoPlay=RECYCLER\YoIgDnR.exe
shell\Open\Command=RECYCLER\YoIgDnR.exe
shell\Open\Default=1
shell\Explore\command=RECYCLER\YoIgDnR.exe
shell\Autoplay\Command=RECYCLER\YoIgDnR.exe

Dropping Routine

This worm sets the attributes of its dropped file(s) to the following:

Hidden
Read Only
System

SOLUTION

Minimum Scan Engine: 8.900

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

Identify and delete files detected as WORM_OTORUN.SMXY using either the Startup Disk or Recovery Console

[ Learn More ]

To identify and delete the malware/grayware file:

• On Windows XP and Server 2003 systems:

Scan your computer with your Trend Micro product and then take note of the names of the malware/grayware files detected.
Click Start>Run. In the Open input box, type secpol.msc and press Enter.
In the left panel, double-click Local Policies>Security Options.
In the right panel, double-click Recovery Console: Allow floppy copy and access to all drives and folders.
Select Enabled and click OK.
Insert the Windows Installation CD into the CD drive, then restart your computer.
When prompted, press any key to boot from the CD.
On the main menu, type r to go to the Recovery Console.
Type the number that corresponds to the drive and directory that contains Windows (usually C:\WINDOWS) and press Enter.
Type the Administrator password and press Enter.
In the input box, type the following then press Enter:
SET AllowAllPaths = TRUE
del "{malware/grayware path and file name}"
Type exit and press Enter to restart the system normally.

• On Windows Vista and 7 systems:

Scan your computer with your Trend Micro product and then take note of the names of the malware/grayware files detected.
Insert your Windows Installation DVD in the DVD drive, then Press the restart button.
When prompted, press any key to boot from the CD.
Depending on your Windows Installation DVD, you might be required to select the installation language. Then on the Install Windows window, choose your language, locale, and keyboard layout or input method. Click Next, then click Repair your computer.
Select Use recovery tools that can help fix problems starting Windows. Select your installation of Windows. Click Next.
If the Startup Repair window appears, click Cancel, Yes, then Finish.
In the System Recovery Options window, click Command Prompt.
In the Command Prompt window, type the following then press Enter:
BootRec.exe /fixmbr
del "{malware/grayware path and file name}"
Type exit and press Enter to close the Command Prompt window.
Click Restart to restart the system normally.

Step 3

Restart in Safe Mode

[ Learn More ]

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
- WindowMessenger
  %System Root%\RECYCLER\{SID}\WinSysApp.exe
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
  Windows Alerter
  %Program Files%\Windows Alerter\WinAlert.exe
  In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
  Windows Common Files Manager
  %Program Files%\Windows\Common Files\Commgr.exe
  In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
  WindowMessenger
  %System Root%\RECYCLER\{SID}\WinSysApp.exe
  In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
  Windows Alerter
  %Program Files%\Windows Alerter\WinAlert.exe
  In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
  Windows Common Files Manager
  %Program Files%\Windows\Common Files\Commgr.exe
  
  To delete the registry value this malware/grayware created:
  
  Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
  
  In the left panel, double-click the following:
  HKEY_CURRENT_USER>Software>Microsoft>Windows>CurrentVersion>Run
  In the right panel, locate and delete the entry:
  WindowMessenger =
  Again In the right panel, locate and delete the entry:
  Windows Alerter =
  Again In the right panel, locate and delete the entry:
  Windows Common Files Manager =
  In the left panel, double-click the following:
  HKEY_LOCAL_MACHINE>SOFTWARE>Microsoft>Windows>CurrentVersion>Run
  In the right panel, locate and delete the entry:
  WindowMessenger =
  Again In the right panel, locate and delete the entry:
  Windows Alerter =
  Again In the right panel, locate and delete the entry:
  Windows Common Files Manager =
  
  Close Registry Editor.

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
From: Hidden = 2
To: 1
In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
From: HideFileExt = 1
To: 0
In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
From: SuperHidden = 0
To: 1
In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
From: ShowSuperHidden =0
To: 1

To restore registry values this malware/grayware modified:

Open Registry Editor. To do this:

On Windows 2000, XP, and Server 2003:
Click Start>Run, type REGEDIT in the text box provided, and then press Enter.

On Windows Vista and 7:
Click the Start button, type REGEDIT in the Search input field then press Enter.

In the left panel, double-click the following:
HKEY_CURRENT_USER>Software>Microsoft>Windows>CurrentVersion>Explorer>Advanced
In the right panel, locate the registry value:
Hidden = 2
Right-click on the value name and choose Modify. Change the value data of this entry to:
Hidden = 1
Again In the right panel, locate the registry value:
HideFileExt = 1
Right-click on the value name and choose Modify. Change the value data of this entry to:
HideFileExt = 0
Again In the right panel, locate the registry value:
SuperHidden = 0
Right-click on the value name and choose Modify. Change the value data of this entry to:
SuperHidden = 1
Again In the right panel, locate the registry value:
ShowSuperHidden = 0
Right-click on the value name and choose Modify. Change the value data of this entry to:
ShowSuperHidden = 1

Close Registry Editor.

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.
In %System Root%\RECYCLER\{SID}

To delete the malware/grayware folder:

Right-click Start then click Search... or Find..., depending on the version of Windows you are running.

In the Named input box, type:
%System Root%\RECYCLER>{SID}

In the Look In drop-down list, select My Computer, then press Enter.

Once located, select the folder then press SHIFT+DELETE to permanently delete the folder.

Step 7

Search and delete AUTORUN.INF files created by WORM_OTORUN.SMXY that contain these strings

[ Learn More ]

In [Autorun]
Open=RECYCLER\YoIgDnR.exe
Explore=RECYCLER\YoIgDnR.exe
AutoPlay=RECYCLER\YoIgDnR.exe
shell\Open\Command=RECYCLER\YoIgDnR.exe
shell\Open\Default=1
shell\Explore\command=RECYCLER\YoIgDnR.exe
shell\Autoplay\Command=RECYCLER\YoIgDnR.exe
To identify and delete AUTORUN.INF files created:

Right-click the Start button then choose Search... or Find..., depending on the version of Windows you are running.

In the Named input box, type:
AUTORUN.INF

In the Look in: drop-down list, select a drive, then press Enter.

Select the file, then open using Notepad.

Check if the following lines are present in the file:
[Autorun]&&Open=RECYCLER>YoIgDnR.exe&&Explore=RECYCLER>YoIgDnR.exe&&AutoPlay=RECYCLER>YoIgDnR.exe&&shell>Open>Command=RECYCLER>YoIgDnR.exe&&shell>Open>Default=1&&shell>Explore>command=RECYCLER>YoIgDnR.exe&&shell>Autoplay>Command=RECYCLER>YoIgDnR.exe

If the lines are present, delete the file.

Repeat steps 3 to 6 for the remaining AUTORUN.INF files in other remaining removable drives.

Close Search Results.

Step 8

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

WORM_OTORUN.SMXY

OVERVIEW

TECHNICAL DETAILS

SOLUTION

Resources

Support

About Trend

Country Headquarters

WORM_OTORUN.SMXY

OVERVIEW

TECHNICAL DETAILS

SOLUTION

Resources

Support

About Trend

Country Headquarters

The Americas

Middle East & Africa

Europe

Asia & Pacific