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WORM_SCUDY.SMA

July 07, 2013
 ALIASES:

TrojanDropper:Win32/Scudy.A (Microsoft); Generic Dropper.nt (McAfee); Hacktool.Rootkit (Symantec); Trojan.Win32.Scar.lzt (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan:W32/Scar.O (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.

  TECHNICAL DETAILS

File Size:

5,369,901 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

23 Jul 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.

Installation

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

  • %System Root%\Config.Msi\5ce97.rbf.exe
  • %Program Files%\Common Files\Microsoft Shared\DAO.exe
  • %Program Files%\Common Files\Microsoft Shared\MSInfo\msinfo32.exe

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)

It creates the following folders:

  • %System Root%\Config.Msi
  • %System Root%\S-1-9-85-0512001
  • %System Root%\HELP

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

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\RunOnce
debugger = "%System Root%\Config.Msi\5ce97.rbf.exe"

Other System Modifications

This worm deletes the following files:

  • %System Root%\S-1-9-85-0512001\dfb7ed52902637ed99232a5adf78384e6d8f3007_66f0677329a7b8c61cf274b27660 .exe
  • %System Root%\S-1-9-85-0512001\msinfo32.exe
  • %Windows%\SoftwareDistribution\DataStore\Logs\edbtmp.log

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %Windows% is the Windows folder, which is usually C:\Windows.)

It adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\INTEL

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\INTEL
999 = "1"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
ShowSuperHidden = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\INTEL
01 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\INTEL
02 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\INTEL
03 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\INTEL
04 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\INTEL
05 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\INTEL
06 = "0"

HKEY_LOCAL_MACHINE\SOFTWARE\INTEL
07 = "0"

It modifies the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
Hidden = "2"

(Note: The default value data of the said registry entry is 2.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
HideFileExt = "1"

(Note: The default value data of the said registry entry is 1.)

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
SuperHidden = "0"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Control\Lsa
forceguest = "0"

(Note: The default value data of the said registry entry is 1.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\lanmanserver
Start = "2"

(Note: The default value data of the said registry entry is 2.)

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\lanmanworkstation
Start = "2"

(Note: The default value data of the said registry entry is 2.)

Dropping Routine

This worm drops the following files:

  • %System Root%\dfb7ed52902637ed99232a5adf78384e6d8f3007_66f0677329a7b8c61cf274b27660 .exe
  • %System%\Drivers\PCIDump.sys
  • %System Root%\Config.Msi\ssss.wav
  • %Windows%\security\database\db32.idx
  • %System Root%\Config.Msi\yyyy.bmp
  • %System Root%\HELP\939516032.wav
  • %System Root%\HELP\939516032.JPG
  • %System Root%\S-1-9-85-0512001\dfb7ed52902637ed99232a5adf78384e6d8f3007_66f0677329a7b8c61cf274b27660 .exe
  • %System Root%\S-1-9-85-0512001\msinfo32.exe

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %System% is the Windows system folder, which is usually C:\Windows\System32.. %Windows% is the Windows folder, which is usually C:\Windows.)

Other Details

This worm connects to the following possibly malicious URL:

  • http://theworldnews.{BLOCKED}st5.com/online.php?{random characters}
  • http://theworldnews.{BLOCKED}st5.com/en/us/defualt.aspx

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.200

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

Restart in Safe Mode

[ Learn More ]

Step 3

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
    • INTEL

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce
    • debugger = "%System Root%\Config.Msi\5ce97.rbf.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\INTEL
    • 999 = "1"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • ShowSuperHidden = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\INTEL
    • 01 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\INTEL
    • 02 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\INTEL
    • 03 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\INTEL
    • 04 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\INTEL
    • 05 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\INTEL
    • 06 = "0"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\INTEL
    • 07 = "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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: Hidden = "2"
      To: Hidden = ""2""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • From: HideFileExt = "1"
      To: HideFileExt = ""1""
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
    • SuperHidden = "0"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Lsa
    • From: forceguest = "0"
      To: forceguest = ""1""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\lanmanserver
    • From: Start = "2"
      To: Start = ""2""
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\lanmanworkstation
    • From: Start = "2"
      To: Start = ""2""

Step 6

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.
  • %System Root%\dfb7ed52902637ed99232a5adf78384e6d8f3007_66f0677329a7b8c61cf274b27660 .exe
  • %System%\Drivers\PCIDump.sys
  • %System Root%\Config.Msi\ssss.wav
  • %Windows%\security\database\db32.idx
  • %System Root%\Config.Msi\yyyy.bmp
  • %System Root%\HELP\939516032.wav
  • %System Root%\HELP\939516032.JPG
  • %System Root%\S-1-9-85-0512001\dfb7ed52902637ed99232a5adf78384e6d8f3007_66f0677329a7b8c61cf274b27660 .exe
  • %System Root%\S-1-9-85-0512001\msinfo32.exe

Step 7

Search and delete these folders

[ 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.
  • %System Root%\Config.Msi
  • %System Root%\S-1-9-85-0512001
  • %System Root%\HELP

Step 8

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

Step 9

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.

  • %System Root%\S-1-9-85-0512001\dfb7ed52902637ed99232a5adf78384e6d8f3007_66f0677329a7b8c61cf274b27660 .exe
  • %System Root%\S-1-9-85-0512001\msinfo32.exe
  • %Windows%\SoftwareDistribution\DataStore\Logs\edbtmp.log


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