Analysis by: Sabrina Lei Sioting
 PLATFORM:

Windows 2000, XP, Server 2003

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This worm arrives as attachment to mass-mailed email messages.

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: 44,032 bytes
File Type: PE
Memory Resident: No
Initial Samples Received Date: 28 Jul 2010

Arrival Details

This worm arrives as attachment to mass-mailed email messages.

Installation

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

  • %WINDOWS%\svchost.exe

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = Explorer.exe %WINDOWS%\svchost.exe

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

Other System Modifications

This worm also creates the following registry entry(ies) as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Image File Execution Options\
{exe found}
Debugger = "svchost.exe"

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

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

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

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

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

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

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

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\DomainProfile
EnableFirewall = "0"

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

It 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
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 of itself in all physical and removable drives:

  • N95_Image13022010.scr
  • open.exe

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=open.exe
icon=%windir%\system32\shell32.dll,8
action=Open Drive to view files
shell\open=Open
shell\open\command=open.exe
shell\open\default=1

Download Routine

This worm accesses the following websites to download files:

  • http://{BLOCKED}s.lycos.co.uk/iqreporters/ff.iq
  • http://{BLOCKED}s.lycos.co.uk/iqreporters/gc.iq
  • http://{BLOCKED}s.lycos.co.uk/iqreporters/ie.iq
  • http://{BLOCKED}s.lycos.co.uk/iqreporters/im.iq
  • http://{BLOCKED}s.lycos.co.uk/iqreporters/m.iq
  • http://{BLOCKED}s.lycos.co.uk/iqreporters/op.iq
  • http://{BLOCKED}s.lycos.co.uk/iqreporters/pspv.iq
  • http://{BLOCKED}s.lycos.co.uk/iqreporters/rd.iq
  • http://{BLOCKED}s.lycos.co.uk/iqreporters/SendEmail.iq
  • http://{BLOCKED}s.lycos.co.uk/iqreporters/tryme.iq
  • http://{BLOCKED}s.lycos.co.uk/iqreporters/w.iq
  • http://{BLOCKED}s.multimania.co.uk/iqreporters/ff.iq
  • http://{BLOCKED}s.multimania.co.uk/iqreporters/gc.iq
  • http://{BLOCKED}s.multimania.co.uk/iqreporters/ie.iq
  • http://{BLOCKED}s.multimania.co.uk/iqreporters/im.iq
  • http://{BLOCKED}s.multimania.co.uk/iqreporters/m.iq
  • http://{BLOCKED}s.multimania.co.uk/iqreporters/op.iq
  • http://{BLOCKED}s.multimania.co.uk/iqreporters/pspv.iq
  • http://{BLOCKED}s.multimania.co.uk/iqreporters/rd.iq
  • http://{BLOCKED}s.multimania.co.uk/iqreporters/SendEmail.iq
  • http://{BLOCKED}s.multimania.co.uk/iqreporters/tryme.iq
  • http://{BLOCKED}s.multimania.co.uk/iqreporters/w.iq

  SOLUTION

Minimum Scan Engine: 8.900
VSAPI PATTERN File: 07.364.09
VSAPI PATTERN Date: 05 Aug 2010
VSAPI PATTERN Date: 8/5/2010 12:00:00 AM

Step 1

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\Image File Execution Options\{exe found}
    • Debugger = svchost.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
    • EnableLUA = 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
    • EnableVirtualization = 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
    • PromptOnSecureDesktop = 0
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\DomainProfile
    • EnableFirewall = 0

Step 2

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\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
    • From: Shell = Explorer.exe %Windows%svchost.exe
      To: Explorer.exe
  • 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: ShowSuperHidden = 0
      To: 1
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: SuperHidden = 0
      To: 1

Step 3

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%\svchost.exe 
N95_Image13022010.scr 
open.exe 

Step 4

Scan your computer with your Trend Micro product to delete files detected as WORM_AUTORUN.NAD. 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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