WORM_SOCKS.BL

 Modified by: Sabrina Lei Sioting

 ALIASES:

Backdoor:Win32/Koceg.B (Microsoft); W32.Mandaph (Symantec), Worm.Win32.Socks.bt (Sunbelt), W32/Socks.A.gen!Eldorado (Fprot), Worm.Win32.Socks (Ikarus),

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

  TECHNICAL DETAILS

File Size:

7,566,619 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

17 Oct 2008

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.

Installation

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

  • %System%\drivers\spools.exe
  • %AppDataLocal%\cftmon.exe

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local on Windows Vista and 7.)

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
ntuser = "%System%\drivers\spools.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
autoload = "%AppDataLocal%\cftmon.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
ntuser = "%System%\drivers\spools.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
autoload = "%AppDataLocal%\cftmon.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"

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
UserInit = "%System%\userinit.exe,"

(Note: The default value data of the said registry entry is %Windows%\system32\userinit.exe,.)

Other System Modifications

This worm modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
UIHost = "logonui.exe"

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

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\Schedule
ImagePath = "%System%\drivers\spools.exe"

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

Dropping Routine

This worm drops the following files:

  • %User Profile%\ftpdll.dll
  • %System%\ftpdll.dll

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.. %System% is the Windows system folder, which is usually C:\Windows\System32.)

Other Details

This worm connects to the following possibly malicious URL:

  • http://{BLOCKED}e.com/?&v=krampt
  • http://{BLOCKED}e.net/?&v=krampt

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

5.604.08

FIRST VSAPI PATTERN DATE:

17 Oct 2008

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_SOCKS.BL using either the Startup Disk or Recovery Console

[ Learn More ]

Step 3

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
    • ntuser = "%System%\drivers\spools.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • autoload = "%AppDataLocal%\cftmon.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • ntuser = "%System%\drivers\spools.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • autoload = "%AppDataLocal%\cftmon.exe"

Step 4

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"
      To: Shell = Explorer.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
    • From: UserInit = "%System%\userinit.exe,"
      To: UserInit = %System%\userinit.exe,
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
    • From: UIHost = "logonui.exe"
      To: UIHost = {random values}
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Schedule
    • From: ImagePath = "%System%\drivers\spools.exe"
      To: ImagePath = {random values}

Step 5

Search and delete these components

[ Learn More ]
There may be some components 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 Profile%\tpdll.dll
  • %System%\tpdll.dll

Step 6

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