ADW_SOMOTO

 Modified by: Jaime Benigno Reyes

 ALIASES:

a variant of Win32/Somoto.A application(Eset)

 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:
 INFORMATION EXPOSURE:

  • Threat Type: Adware

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

This adware may be manually installed by a user.

  TECHNICAL DETAILS

File Size:

3,544,072 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

10 Jun 2014

Payload:

Downloads files

Arrival Details

This adware may be manually installed by a user.

Installation

This adware adds the following folders:

  • %All Users Profile%\SafetyNut (Windows Vista and higher versions)
  • %All Users Profile%\Application Data\SafetyNut (Versions lower than Windows Vista)

(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.)

It drops the following files:

  • %User Temp%\nsi16.tmp\bi_client.exe
  • %User Temp%\nsn13.tmp\bi_client.exe
  • %User Temp%\nst10.tmp\bi_client.exe
  • %User Temp%\nstD.tmp\bi_client.exe
  • %User Temp%\nsv19.tmp\bi_client.exe
  • %User Temp%\biclient.exe

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

Other System Modifications

This adware adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\SafetyNut

HKEY_LOCAL_MACHINE\SOFTWARE\SafetyNut\
General

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\Session Manager
PendingFileRenameOperations = "%User Temp%\nstD.tmp\bi_client.exe"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\Session Manager
PendingFileRenameOperations = "%User Temp%\biclient.exe"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
DirectDraw\MostRecentApplication
Name = "biclient.exe"

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

NOTES:

ADW_SOMOTO is used to download applications from the following URLs:

  • http://{BLOCKED}i.{BLOCKED}v.com/awjpfreezip73272/freezipuyiv
  • http://{BLOCKED}ln.{BLOCKED}ldog.com/css/Tokyo/TokyoDefault.css
  • http://{BLOCKED}ln.{BLOCKED}ldog.com/images/Tokyo/tokyoLightGrayStripesBG.jpg
  • http://{BLOCKED}c.{BLOCKED}v.com/js/libs/storage.swf?767416
  • http://{BLOCKED}i.{BLOCKED}v.com/pinger

  SOLUTION

Minimum Scan Engine:

9.700

SSAPI PATTERN File:

1.475.00

SSAPI PATTERN Date:

16 Jan 2013

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

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\SYSTEM\CurrentControlSet\Control\Session Manager
    • PendingFileRenameOperations = "%User Temp%\nstD.tmp\bi_client.exe"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager
    • PendingFileRenameOperations = "%User Temp%\biclient.exe"

Step 3

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\DirectDraw\MostRecentApplication
    • From: Name = "biclient.exe"
      To: Name = aim.exe

Step 4

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\SOFTWARE
    • SafetyNut

Step 5

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.
  • %All Users Profile%\SafetyNut (Windows Vista and higher versions)
  • %All Users Profile%\Application Data\SafetyNut (Versions lower than Windows Vista)

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.
  • %User Temp%\nsi16.tmp\bi_client.exe
  • %User Temp%\nsn13.tmp\bi_client.exe
  • %User Temp%\nst10.tmp\bi_client.exe
  • %User Temp%\nstD.tmp\bi_client.exe
  • %User Temp%\nsv19.tmp\bi_client.exe
  • %User Temp%\biclient.exe

Step 7

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