TROJ_STARTP.SMHU
Trojan:Win32/Startpage.OD (Microsoft); Generic StartPage!ue (McAfee); ARC:NSIS, [data0001]:Trojan.NSIS.StartPage.bt (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Trojan:W32/Agent.DSQO (FSecure)
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 deletes the initially executed copy of itself.
TECHNICAL DETAILS
65,089 bytes
EXE
No
08 Nov 2011
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:
- %Program Files%\Microsoft11
- %Program Files%\Microsoft11\Internet Explorar
- %System Root%\DOCUME~1
- %System Root%\DOCUME~1\ADMINI~1
- %User Profile%\LOCALS~1
- %User Temp%\nss3.tmp
- %System Root%\Documents and Settings
- %System Root%\Documents and Settings\All Users
(Note: %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).. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.. %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%\nsz1.tmp
- %User Temp%\nss3.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 deletes the following folders:
- %User Temp%\nss3.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\.of
HKEY_CLASSES_ROOT\offile\DefaultIcon
HKEY_CLASSES_ROOT\offile\shell\
open\command
It modifies the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
CLSID\{871C5380-42A0-1069-A2EA-08002B30309D}\ShellFolder
Attributes = 133ec2
(Note: The default value data of the said registry entry is 0.)
Dropping Routine
This Trojan drops the following files:
- %User Temp%\nsz2.tmp
- %Program Files%\Microsoft11\Internet Explorar\target.lnk
- %User Temp%\nss3.tmp\AccessControl.dll
- %Desktop%\Internet Explorar.of
- %Windows%\tbgw.ico
- %Desktop%\ÌÔ ±¦ Íø ¹º.lnk
(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.. %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).. %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.. %Windows% is the Windows folder, which is usually C:\Windows.)
Other Details
This Trojan deletes the initially executed copy of itself
This report is generated via an automated analysis system.
SOLUTION
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
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
- .of
- In HKEY_CLASSES_ROOT\offile
- DefaultIcon
- In HKEY_CLASSES_ROOT\offile\shell\open
- command
Step 3
Restore these modified registry values
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\CLSID\{871C5380-42A0-1069-A2EA-08002B30309D}\ShellFolder
- From: Attributes=133ec2
To: Attributes=0
- From: Attributes=133ec2
Step 4
Search and delete these folders
- %Program Files%\Microsoft11
- %Program Files%\Microsoft11\Internet Explorar
- %System Root%\DOCUME~1
- %System Root%\DOCUME~1\ADMINI~1
- %User Profile%\LOCALS~1
- %User Temp%\nss3.tmp
- %System Root%\Documents and Settings
- %System Root%\Documents and Settings\All Users
Step 5
Search and delete these components
- %User Temp%\nsz2.tmp
- %Program Files%\Microsoft11\Internet Explorar\target.lnk
- %User Temp%\nss3.tmp\AccessControl.dll
- %Desktop%\Internet Explorar.of
- %Windows%\tbgw.ico
- %Desktop%\ÌÔ ±¦ Íø ¹º.lnk
Step 6
Scan your computer with your Trend Micro product to delete files detected as TROJ_STARTP.SMHU. 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%\nsz1.tmp
- %User Temp%\nss3.tmp
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