VBS_AGENT.BOI

This Trojan 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.

File Size: 95,456 bytes

File Type: EXE

Memory Resident: No

Initial Samples Received Date: 09 May 2013

Arrival Details

This Trojan 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 Trojan creates the following folders:

%System Root%\Documents and Settings\Wilbert
%Program Files%\UltraEdit
%Program Files%\UltraEdit\369
%Program Files%\UltraEdit\icofiles
%System Root%\DOCUME~1
%System Root%\DOCUME~1\Wilbert
%User Profile%\LOCALS~1
%User Temp%\nscF.tmp

(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).. %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.. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

Other System Modifications

This Trojan deletes the following files:

%User Temp%\nsy1.tmp
%User Temp%\nscF.tmp

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

It adds the following registry keys:

HKEY_CLASSES_ROOT\.zx

HKEY_CLASSES_ROOT\ZxFile

HKEY_CLASSES_ROOT\ZxFile\CLSID

HKEY_CLASSES_ROOT\ZxFile\DefaultIcon

HKEY_CLASSES_ROOT\ZxFile\ScriptEngine

HKEY_CLASSES_ROOT\ZxFile\shell\
open

HKEY_CLASSES_ROOT\ZxFile\shell\
open\Command

HKEY_CLASSES_ROOT\.zx2

HKEY_CLASSES_ROOT\ZxFile2

HKEY_CLASSES_ROOT\ZxFile2\CLSID

HKEY_CLASSES_ROOT\ZxFile2\DefaultIcon

HKEY_CLASSES_ROOT\ZxFile2\ScriptEngine

HKEY_CLASSES_ROOT\ZxFile2\shell\
open

HKEY_CLASSES_ROOT\ZxFile2\shell\
open\Command

HKEY_CLASSES_ROOT\.zx3

HKEY_CLASSES_ROOT\ZxFile3

HKEY_CLASSES_ROOT\ZxFile3\CLSID

HKEY_CLASSES_ROOT\ZxFile3\DefaultIcon

HKEY_CLASSES_ROOT\ZxFile3\ScriptEngine

HKEY_CLASSES_ROOT\ZxFile3\shell\
open

HKEY_CLASSES_ROOT\ZxFile3\shell\
open\Command

HKEY_CLASSES_ROOT\.zx4

HKEY_CLASSES_ROOT\ZxFile4

HKEY_CLASSES_ROOT\ZxFile4\CLSID

HKEY_CLASSES_ROOT\ZxFile4\DefaultIcon

HKEY_CLASSES_ROOT\ZxFile4\ScriptEngine

HKEY_CLASSES_ROOT\ZxFile4\shell\
open

HKEY_CLASSES_ROOT\ZxFile4\shell\
open\Command

HKEY_CLASSES_ROOT\.zx5

HKEY_CLASSES_ROOT\ZxFile5

HKEY_CLASSES_ROOT\ZxFile5\CLSID

HKEY_CLASSES_ROOT\ZxFile5\DefaultIcon

HKEY_CLASSES_ROOT\ZxFile5\ScriptEngine

HKEY_CLASSES_ROOT\ZxFile5\shell\
open

HKEY_CLASSES_ROOT\ZxFile5\shell\
open\Command

HKEY_CLASSES_ROOT\.zx6

HKEY_CLASSES_ROOT\ZxFile6

HKEY_CLASSES_ROOT\ZxFile6\CLSID

HKEY_CLASSES_ROOT\ZxFile6\DefaultIcon

HKEY_CLASSES_ROOT\ZxFile6\ScriptEngine

HKEY_CLASSES_ROOT\ZxFile6\shell\
open

HKEY_CLASSES_ROOT\ZxFile6\shell\
open\Command

HKEY_CLASSES_ROOT\.zx7

HKEY_CLASSES_ROOT\ZxFile7

HKEY_CLASSES_ROOT\ZxFile7\CLSID

HKEY_CLASSES_ROOT\ZxFile7\DefaultIcon

HKEY_CLASSES_ROOT\ZxFile7\ScriptEngine

HKEY_CLASSES_ROOT\ZxFile7\shell\
open

HKEY_CLASSES_ROOT\ZxFile7\shell\
open\Command

HKEY_CLASSES_ROOT\.zx8

HKEY_CLASSES_ROOT\ZxFile8

HKEY_CLASSES_ROOT\ZxFile8\CLSID

HKEY_CLASSES_ROOT\ZxFile8\DefaultIcon

HKEY_CLASSES_ROOT\ZxFile8\ScriptEngine

HKEY_CLASSES_ROOT\ZxFile8\shell\
open

HKEY_CLASSES_ROOT\ZxFile8\shell\
open\Command

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
NoInternetIcon = "1"

Dropping Routine

This Trojan drops the following files:

%User Profile%\Templates\mytest.js
%Program Files%\UltraEdit\icofiles\tt.ico
%Program Files%\UltraEdit\icofiles\tx2.ico
%Program Files%\UltraEdit\icofiles\ff3.ico
%Program Files%\UltraEdit\icofiles\gg.ico
%Program Files%\UltraEdit\icofiles\sg.ico
%Program Files%\UltraEdit\icofiles\ttb.ico
%User Temp%\nscF.tmp\ShellLink.dll
%User Profile%\Quick Launch\Launch Internet Explorer Browser.zx
%User Temp%\nscF.tmp\System.dll
%Desktop%\Internet Explorer.zx
%User Profile%\Quick Launch\Internet Explorer.zx
%Desktop%\ÎÒµÄÌÔ±¦.zx2
%Desktop%\ÎÒµÄÐ¡ÓÎÏ·.zx3

(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.. %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).. %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %Desktop% is the current user's desktop, which is usually C:\Documents and Settings\{User Name}\Desktop on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\Desktop on Windows Vista and 7.)

This report is generated via an automated analysis system.

Minimum Scan Engine: 9.300

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

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 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_CLASSES_ROOT
- .zx

In HKEY_CLASSES_ROOT
- ZxFile

In HKEY_CLASSES_ROOT\ZxFile
- CLSID

In HKEY_CLASSES_ROOT\ZxFile
- DefaultIcon

In HKEY_CLASSES_ROOT\ZxFile
- ScriptEngine

In HKEY_CLASSES_ROOT\ZxFile\shell
- open

In HKEY_CLASSES_ROOT\ZxFile\shell\open
- Command

In HKEY_CLASSES_ROOT
- .zx2

In HKEY_CLASSES_ROOT
- ZxFile2

In HKEY_CLASSES_ROOT\ZxFile2
- CLSID

In HKEY_CLASSES_ROOT\ZxFile2
- DefaultIcon

In HKEY_CLASSES_ROOT\ZxFile2
- ScriptEngine

In HKEY_CLASSES_ROOT\ZxFile2\shell
- open

In HKEY_CLASSES_ROOT\ZxFile2\shell\open
- Command

In HKEY_CLASSES_ROOT
- .zx3

In HKEY_CLASSES_ROOT
- ZxFile3

In HKEY_CLASSES_ROOT\ZxFile3
- CLSID

In HKEY_CLASSES_ROOT\ZxFile3
- DefaultIcon

In HKEY_CLASSES_ROOT\ZxFile3
- ScriptEngine

In HKEY_CLASSES_ROOT\ZxFile3\shell
- open

In HKEY_CLASSES_ROOT\ZxFile3\shell\open
- Command

In HKEY_CLASSES_ROOT
- .zx4

In HKEY_CLASSES_ROOT
- ZxFile4

In HKEY_CLASSES_ROOT\ZxFile4
- CLSID

In HKEY_CLASSES_ROOT\ZxFile4
- DefaultIcon

In HKEY_CLASSES_ROOT\ZxFile4
- ScriptEngine

In HKEY_CLASSES_ROOT\ZxFile4\shell
- open

In HKEY_CLASSES_ROOT\ZxFile4\shell\open
- Command

In HKEY_CLASSES_ROOT
- .zx5

In HKEY_CLASSES_ROOT
- ZxFile5

In HKEY_CLASSES_ROOT\ZxFile5
- CLSID

In HKEY_CLASSES_ROOT\ZxFile5
- DefaultIcon

In HKEY_CLASSES_ROOT\ZxFile5
- ScriptEngine

In HKEY_CLASSES_ROOT\ZxFile5\shell
- open

In HKEY_CLASSES_ROOT\ZxFile5\shell\open
- Command

In HKEY_CLASSES_ROOT
- .zx6

In HKEY_CLASSES_ROOT
- ZxFile6

In HKEY_CLASSES_ROOT\ZxFile6
- CLSID

In HKEY_CLASSES_ROOT\ZxFile6
- DefaultIcon

In HKEY_CLASSES_ROOT\ZxFile6
- ScriptEngine

In HKEY_CLASSES_ROOT\ZxFile6\shell
- open

In HKEY_CLASSES_ROOT\ZxFile6\shell\open
- Command

In HKEY_CLASSES_ROOT
- .zx7

In HKEY_CLASSES_ROOT
- ZxFile7

In HKEY_CLASSES_ROOT\ZxFile7
- CLSID

In HKEY_CLASSES_ROOT\ZxFile7
- DefaultIcon

In HKEY_CLASSES_ROOT\ZxFile7
- ScriptEngine

In HKEY_CLASSES_ROOT\ZxFile7\shell
- open

In HKEY_CLASSES_ROOT\ZxFile7\shell\open
- Command

In HKEY_CLASSES_ROOT
- .zx8

In HKEY_CLASSES_ROOT
- ZxFile8

In HKEY_CLASSES_ROOT\ZxFile8
- CLSID

In HKEY_CLASSES_ROOT\ZxFile8
- DefaultIcon

In HKEY_CLASSES_ROOT\ZxFile8
- ScriptEngine

In HKEY_CLASSES_ROOT\ZxFile8\shell
- open

In HKEY_CLASSES_ROOT\ZxFile8\shell\open
- Command

To delete the registry key this malware/grayware created:

Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
In the left panel, double-click the following:
HKEY_CLASSES_ROOT
Still in the left panel, locate and delete the key:
.zx
Again Still in the left panel, locate and delete the key:
ZxFile
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile
Still in the left panel, locate and delete the key:
CLSID
Again Still in the left panel, locate and delete the key:
DefaultIcon
Again Still in the left panel, locate and delete the key:
ScriptEngine
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile>shell
Still in the left panel, locate and delete the key:
open
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile>shell>open
Still in the left panel, locate and delete the key:
Command
Again Still in the left panel, locate and delete the key:
.zx2
Again Still in the left panel, locate and delete the key:
ZxFile2
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile2
Still in the left panel, locate and delete the key:
CLSID
Again Still in the left panel, locate and delete the key:
DefaultIcon
Again Still in the left panel, locate and delete the key:
ScriptEngine
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile2>shell
Still in the left panel, locate and delete the key:
open
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile2>shell>open
Still in the left panel, locate and delete the key:
Command
Again Still in the left panel, locate and delete the key:
.zx3
Again Still in the left panel, locate and delete the key:
ZxFile3
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile3
Still in the left panel, locate and delete the key:
CLSID
Again Still in the left panel, locate and delete the key:
DefaultIcon
Again Still in the left panel, locate and delete the key:
ScriptEngine
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile3>shell
Still in the left panel, locate and delete the key:
open
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile3>shell>open
Still in the left panel, locate and delete the key:
Command
Again Still in the left panel, locate and delete the key:
.zx4
Again Still in the left panel, locate and delete the key:
ZxFile4
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile4
Still in the left panel, locate and delete the key:
CLSID
Again Still in the left panel, locate and delete the key:
DefaultIcon
Again Still in the left panel, locate and delete the key:
ScriptEngine
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile4>shell
Still in the left panel, locate and delete the key:
open
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile4>shell>open
Still in the left panel, locate and delete the key:
Command
Again Still in the left panel, locate and delete the key:
.zx5
Again Still in the left panel, locate and delete the key:
ZxFile5
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile5
Still in the left panel, locate and delete the key:
CLSID
Again Still in the left panel, locate and delete the key:
DefaultIcon
Again Still in the left panel, locate and delete the key:
ScriptEngine
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile5>shell
Still in the left panel, locate and delete the key:
open
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile5>shell>open
Still in the left panel, locate and delete the key:
Command
Again Still in the left panel, locate and delete the key:
.zx6
Again Still in the left panel, locate and delete the key:
ZxFile6
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile6
Still in the left panel, locate and delete the key:
CLSID
Again Still in the left panel, locate and delete the key:
DefaultIcon
Again Still in the left panel, locate and delete the key:
ScriptEngine
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile6>shell
Still in the left panel, locate and delete the key:
open
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile6>shell>open
Still in the left panel, locate and delete the key:
Command
Again Still in the left panel, locate and delete the key:
.zx7
Again Still in the left panel, locate and delete the key:
ZxFile7
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile7
Still in the left panel, locate and delete the key:
CLSID
Again Still in the left panel, locate and delete the key:
DefaultIcon
Again Still in the left panel, locate and delete the key:
ScriptEngine
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile7>shell
Still in the left panel, locate and delete the key:
open
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile7>shell>open
Still in the left panel, locate and delete the key:
Command
Again Still in the left panel, locate and delete the key:
.zx8
Again Still in the left panel, locate and delete the key:
ZxFile8
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile8
Still in the left panel, locate and delete the key:
CLSID
Again Still in the left panel, locate and delete the key:
DefaultIcon
Again Still in the left panel, locate and delete the key:
ScriptEngine
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile8>shell
Still in the left panel, locate and delete the key:
open
In the left panel, double-click the following:
HKEY_CLASSES_ROOT>ZxFile8>shell>open
Still in the left panel, locate and delete the key:
Command
Close Registry Editor.

Step 4

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%\Templates\mytest.js
%Program Files%\UltraEdit\icofiles\tt.ico
%Program Files%\UltraEdit\icofiles\tx2.ico
%Program Files%\UltraEdit\icofiles\ff3.ico
%Program Files%\UltraEdit\icofiles\gg.ico
%Program Files%\UltraEdit\icofiles\sg.ico
%Program Files%\UltraEdit\icofiles\ttb.ico
%User Temp%\nscF.tmp\ShellLink.dll
%User Profile%\Quick Launch\Launch Internet Explorer Browser.zx
%User Temp%\nscF.tmp\System.dll
%Desktop%\Internet Explorer.zx
%User Profile%\Quick Launch\Internet Explorer.zx
%Desktop%\ÎÒµÄÌÔ±¦.zx2
%Desktop%\ÎÒµÄÐ¡ÓÎÏ·.zx3

Step 5

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%\Documents and Settings\Wilbert
%Program Files%\UltraEdit
%Program Files%\UltraEdit\369
%Program Files%\UltraEdit\icofiles
%System Root%\DOCUME~1
%System Root%\DOCUME~1\Wilbert
%User Profile%\LOCALS~1
%User Temp%\nscF.tmp

Step 6

Scan your computer with your Trend Micro product to delete files detected as VBS_AGENT.BOI. 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 7

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.

%User Temp%\nsy1.tmp
%User Temp%\nscF.tmp

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