VBS_AGENT.BOI
Generic.dx!bdt4 (McAfee); Trojan.JS.Agent.boi (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Downloader.NSIS (AVG)
Windows 2000, Windows XP, Windows Server 2003
Threat Type: Trojan
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
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.
TECHNICAL DETAILS
95,456 bytes
EXE
No
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%\ÎÒµÄСÓÎÏ·.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.
SOLUTION
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
Step 3
Delete this registry key
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
Step 4
Search and delete these components
- %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%\ÎÒµÄСÓÎÏ·.zx3
Step 5
Search and delete these 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
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
Did this description help? Tell us how we did.