ALIASES:

VirTool:Win32/VBInject (Microsoft); Generic Backdoor.xo (McAfee); Trojan.Gen (Symantec); Trojan.Win32.Generic!BT (Sunbelt); Trojan.Generic.6689786 (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: 315,392 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 13 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.

Installation

This worm creates the following folders:

  • %User Profile%\Application Data\app

(Note: %User Profile% is the current user's profile folder, which is usually C:\Windows\Profiles\{user name} on Windows 98 and ME, C:\WINNT\Profiles\{user name} on Windows NT, and C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003.)

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
App = "%User Profile%\app\app.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
App = "%User Profile%\app\app.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{78AE1DAF-B6BA-7BFC-CAD4-FBEDFCE510C2}
StubPath = "%User Profile%\app\app.exe"

HKEY_CURRENT_USER\Software\Microsoft\
Active Setup\Installed Components\{78AE1DAF-B6BA-7BFC-CAD4-FBEDFCE510C2}
StubPath = "%User Profile%\app\app.exe"

Other System Modifications

This worm adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\run

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Active Setup\Installed Components\{78AE1DAF-B6BA-7BFC-CAD4-FBEDFCE510C2}

HKEY_CURRENT_USER\SOFTWARE\Microsoft\
Active Setup\Installed Components\{78AE1DAF-B6BA-7BFC-CAD4-FBEDFCE510C2}

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
SrvID\ID

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
INSTALL\DATE

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
Explorer\run
App = "%User Profile%\app\app.exe"

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
SrvID\ID
UE0G0NEOTK = "APP"

HKEY_CURRENT_USER\Software\VB and VBA Program Settings\
INSTALL\DATE
UE0G0NEOTK = "October 13, 2011"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%System Root%\\{malware file name}.exe = "{random characters}"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%User Profile%\app\app.exe = "%User Profile%\app\app.exe:*:Enabled:Windows Messanger"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
DoNotAllowExceptions = "0"

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

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\Microsoft\Windows\CurrentVersion\policies\Explorer
    • run
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components
    • {78AE1DAF-B6BA-7BFC-CAD4-FBEDFCE510C2}
  • In HKEY_CURRENT_USER\SOFTWARE\Microsoft\Active Setup\Installed Components
    • {78AE1DAF-B6BA-7BFC-CAD4-FBEDFCE510C2}
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\SrvID
    • ID
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\INSTALL
    • DATE

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\Run
    • App = "%User Profile%\app\app.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • App = "%User Profile%\app\app.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Active Setup\Installed Components\{78AE1DAF-B6BA-7BFC-CAD4-FBEDFCE510C2}
    • StubPath = "%User Profile%\app\app.exe"
  • In HKEY_CURRENT_USER\Software\Microsoft\Active Setup\Installed Components\{78AE1DAF-B6BA-7BFC-CAD4-FBEDFCE510C2}
    • StubPath = "%User Profile%\app\app.exe"
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\run
    • App = "%User Profile%\app\app.exe"
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\SrvID\ID
    • UE0G0NEOTK = "APP"
  • In HKEY_CURRENT_USER\Software\VB and VBA Program Settings\INSTALL\DATE
    • UE0G0NEOTK = "October 13, 2011"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %System Root%\{malware file name}.exe = "{random characters}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %User Profile%\app\app.exe = "%User Profile%\app\app.exe:*:Enabled:Windows Messanger"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
    • DoNotAllowExceptions = "0"

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.
  • %User Profile%\Application Data\app

Step 6

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