WORM_SOHANAD.AC


 ALIASES:

Worm:AutoIt/YahLover.R (Microsoft); [.au3]:W32/Yahlover.worm.gen.c (McAfee); PAK:UPX, ARC:Embedded, [script.au3]:IM-Worm.Win32.Sohanad.cq (Kaspersky); Trojan.Win32.AutoIt.gen.1 (v) (Sunbelt); Worm.Generic.66307 (FSecure)

 PLATFORM:

Windows 2000, Windows XP, Windows 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 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.

  TECHNICAL DETAILS

File Size:

181,849 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

14 May 2012

Arrival Details

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

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Task Manager = "%Windows%\svhost32.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
SVCHOST = "%Windows%\svhost.exe"

Other System Modifications

This worm adds the following registry keys:

HKEY_CURRENT_USER\Software\Policies\
Microsoft\Internet Explorer\Control Panel

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System

HKEY_CURRENT_USER\Software\Yahoo\
pager\View\YMSGR_buzz

HKEY_CURRENT_USER\Software\Yahoo\
pager\View\YMSGR_Launchcast

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Policies\
Microsoft\Internet Explorer\Control Panel
Homepage = "1"

HKEY_CURRENT_USER\Software\Yahoo\
pager\View\YMSGR_buzz
content url = "http://{BLOCKED}al-news.com"

HKEY_CURRENT_USER\Software\Yahoo\
pager\View\YMSGR_Launchcast
content url = "http://{BLOCKED}al-news.com"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\Main
Start Page = "http://{BLOCKED}al-news.com"

(Note: The default value data of the said registry entry is http://www.microsoft.com/isapi/redir.dll?prd=ie&pver=6&ar=msnhome.)

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

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

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

Dropping Routine

This worm drops the following files:

  • %Windows%\svhost32.exe
  • %Windows%\svhost.exe

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.)

Other Details

This worm connects to the following possibly malicious URL:

  • http://termex.{BLOCKED}w.com/host.exe
  • http://termex.{BLOCKED}w.com/host2.exe

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Restart in Safe Mode

[ 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.

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_CURRENT_USER\Software\Policies\Microsoft\Internet Explorer
    • Control Panel
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies
    • System
  • In HKEY_CURRENT_USER\Software\Yahoo\pager\View
    • YMSGR_buzz
  • In HKEY_CURRENT_USER\Software\Yahoo\pager\View
    • YMSGR_Launchcast

Step 5

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\CurrentVersion\Run
    • Task Manager = "%Windows%\svhost32.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • SVCHOST = "%Windows%\svhost.exe"
  • In HKEY_CURRENT_USER\Software\Policies\Microsoft\Internet Explorer\Control Panel
    • Homepage = "1"
  • In HKEY_CURRENT_USER\Software\Yahoo\pager\View\YMSGR_buzz
    • content url = "http://{BLOCKED}al-news.com"
  • In HKEY_CURRENT_USER\Software\Yahoo\pager\View\YMSGR_Launchcast
    • content url = "http://{BLOCKED}al-news.com"

Step 6

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_CURRENT_USER\Software\Microsoft\Internet Explorer\Main
    • From: Start Page = "http://{BLOCKED}al-news.com"
      To: Start Page = ""http://www.microsoft.com/isapi/redir.dll?prd=ie&pver=6&ar=msnhome""

Step 7

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%\svhost32.exe
  • %Windows%\svhost.exe

Step 8

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