TROJ_STARTP.SMGA
Trojan:Win32/Startpage.NR (Microsoft); Generic StartPage!sy (McAfee); Adware.StartPage (Symantec); ARC:NSIS, [data0001]:Trojan.Win32.Agent.giyt (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt)
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
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%\Microsoft
- %Program Files%\Microsoft\Internat Explorer
- %System Root%\Documents and Settings
- %System Root%\Documents and Settings\All Users
- %System Root%\DOCUME~1
- %System Root%\DOCUME~1\ADMINI~1
- %User Profile%\LOCALS~1
- %User Temp%\nsa3.tmp
(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.. %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:\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.. %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.)
Other System Modifications
This Trojan deletes the following files:
- %User Temp%\nsx1.tmp
- %User Temp%\nsa3.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.)
It deletes the following folders:
- %User Temp%\nsa3.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.)
It adds the following registry keys:
HKEY_CLASSES_ROOT\.oc
HKEY_CLASSES_ROOT\ocfile\DefaultIcon
HKEY_CLASSES_ROOT\ocfile\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.)
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced
HideFileExt = 1
(Note: The default value data of the said registry entry is 1.)
Dropping Routine
This Trojan drops the following files:
- %User Temp%\nsx2.tmp
- %Program Files%\Microsoft\Internat Explorer\target.lnk
- %Desktop%\Internat Explorar.oc
- %User Temp%\nsa3.tmp\System.dll
(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.. %Program Files% is the default Program Files folder, usually C:\Program Files.. %Desktop% is the current user's desktop, which is usually C:\Windows\Profiles\{user name}\Desktop on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Desktop on Windows NT, and C:\Documents and Settings\{User Name}\Desktop on Windows 2000, XP, and Server 2003.)
Other Details
This Trojan deletes the initially executed copy of itself
This report is generated via an automated analysis system.
SOLUTION
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
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
- .oc
- In HKEY_CLASSES_ROOT\ocfile
- DefaultIcon
- In HKEY_CLASSES_ROOT\ocfile\shell\open
- command
Step 3
Restore this modified registry value
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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\CLSID\{871C5380-42A0-1069-A2EA-08002B30309D}\ShellFolder
- From: Attributes=133ec2
To: Attributes=0
- From: Attributes=133ec2
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced
- From: HideFileExt=1
To: HideFileExt=1
- From: HideFileExt=1
Step 4
Search and delete these folders
- %Program Files%\Microsoft
- %Program Files%\Microsoft\Internat Explorer
- %System Root%\Documents and Settings
- %System Root%\Documents and Settings\All Users
- %System Root%\DOCUME~1
- %System Root%\DOCUME~1\ADMINI~1
- %User Profile%\LOCALS~1
- %User Temp%\nsa3.tmp
Step 5
Search and delete these files
- %User Temp%\nsx2.tmp
- %Program Files%\Microsoft\Internat Explorer\target.lnk
- %Desktop%\Internat Explorar.oc
- %User Temp%\nsa3.tmp\System.dll
Step 6
Scan your computer with your Trend Micro product to delete files detected as TROJ_STARTP.SMGA. 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%\nsx1.tmp
- %User Temp%\nsa3.tmp
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