Modified by: Sabrina Lei Sioting

ALIASES:

Worm.Win32.AutoIt.cb (F-Secure); Win32.Worm.Sohanat.BP(GData); Worm.Win32.AutoIt (Ikarus); Worm.Win32.AutoIt.cb (Kaspersky); W32/YahLover.worm.gen (McAfee); Win32/Autoit.EP.Gen (NOD32); Mal/Sohana-A (Sophos); Worm.Win32.Sohanat.BP (Sunbelt); W32.Imaut.E (Symantec)

 PLATFORM:

Windows 2000, Windows, XP, Windows 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 by connecting affected removable drives to a system. 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 disables Task Manager, Registry Editor, and Folder Options.

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: 267,264 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 11 May 2010

Arrival Details

This worm arrives by connecting affected removable drives to a system.

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%\gphone.exe
  • %Windows%\gphone.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %Windows% is the Windows folder, which is usually C:\Windows.)

It drops the following files:

  • %System%\autorun.ini
  • %Windows%\Tasks\At1.job

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %Windows% is the Windows folder, which is usually C:\Windows.)

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
Yahoo Messengger = "%System%\gphone.exe"

It modifies the following registry entries to ensure it automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Shell = "Explorer.exe gphone.exe"

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

Other System Modifications

This worm adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\Schedule
AtTaskMaxHours = "0"

It modifies the following registry key(s)/entry(ies) as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main
Default_Page_URL = "http://{BLOCKED}inindia.blogspot.com "

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main
Default_Search_URL = "http://{BLOCKED}inindia.blogspot.com "

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main
Search Page = "http://{BLOCKED}inindia.blogspot.com "

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\Main
Start Page = "http://{BLOCKED}inindia.blogspot.com "

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

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Start Page = "http://{BLOCKED}inindia.blogspot.com "

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

It creates the following registry entry(ies) to disable Task Manager, Registry Tools and Folder Options:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NofolderOptions = 1

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableTaskMgr = 1

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableRegistryTools = 1

Propagation

This worm searches for folders in all physical and removable drives then drops copies of itself inside the folder as {folder name}.EXE.

It drops the following copy of itself in all physical and removable drives:

  • New Folder.exe
  • gphone.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=gphone.exe
Shellexecute=gphone.exe
Shell\Open\command=gphone.exe
Shell=Open

Other Details

This worm connects to the following possibly malicious URL:

  • http://{BLOCKED}eandemotion.googlepages.com/setting.ini
  • http://{BLOCKED}lgo.googlepages.com/setting.ini
  • http://{BLOCKED}vatecam.googlepages.com/setting.ini
  • http://{BLOCKED}yoga.googlepages.com/setting.ini

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 7.160.04
FIRST VSAPI PATTERN DATE: 11 May 2010
VSAPI OPR PATTERN File: 7.161.00
VSAPI OPR PATTERN Date: 12 May 2010

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_SOHANAD.DQ using either the Startup Disk or Recovery Console

[ Learn More ]

Step 3

Enable Registry Editor, Task Manager, and Folder options

[ Learn More ]
By doing this step, you also enable other applications/programs disabled by this malware/grayware/spyware.

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
    • Yahoo Messengger = "%System%\gphone.exe"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Schedule
    • AtTaskMaxHours "0"

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\Windows NT\CurrentVersion\Winlogon
    • From: Shell = "Explorer.exe gphone.exe"
      To: Shell = Explorer.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main
    • From: Default_Page_URL = "http://{BLOCKED}inindia.blogspot.com <!-- {BLOCKED} http://googleinindia.blogspot.com -->"
      To: Default_Page_URL = {default homepage}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main
    • From: Default_Search_URL = "http://{BLOCKED}inindia.blogspot.com <!-- {BLOCKED} http://googleinindia.blogspot.com -->"
      To: Default_Search_URL = {default search page}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main
    • From: Search Page = "http://{BLOCKED}inindia.blogspot.com <!-- {BLOCKED} http://googleinindia.blogspot.com -->"
      To: Search Page = {default search page}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main
    • From: Start Page = "http://{BLOCKED}inindia.blogspot.com <!-- {BLOCKED} http://googleinindia.blogspot.com -->"
      To: Start Page = {default homepage}
  • In HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • From: Start Page = "http://{BLOCKED}inindia.blogspot.com <!-- {BLOCKED} http://googleinindia.blogspot.com -->"
      To: Start Page = {default homepage}

Step 6

Search and delete this file

[ Learn More ]
There may be some 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.
  • %System%\autorun.ini
  • %Windows%\Tasks\At1.job

Step 7

Search and delete AUTORUN.INF files created by WORM_SOHANAD.DQ that contain these strings

[ Learn More ]
[Autorun]
Open=gphone.exe
Shellexecute=gphone.exe
Shell\Open\command=gphone.exe
Shell=Open

Step 8

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