TROJ_VILSEL.SMD
TrojanDownloader:Win32/VB.MO (Microsoft); Downloader-CJD (McAfee); Trojan.Dropper (Symantec); Trojan-Downloader.Win32.VB.zly, Trojan.Win32.Vilsel.aotx (Kaspersky); Trojan.Win32.Generic!BT (Sunbelt); Gen:Trojan.Heur.gm0@bbxOrImi (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.
TECHNICAL DETAILS
98,304 bytes
EXE
No
29 Apr 2012
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:
- %User Profile%\Application Data\MSA
(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.)
Other System Modifications
This Trojan modifies the following file(s):
- %System%\wscntfy.exe
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)
It adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\PhishingFilter
HKEY_LOCAL_MACHINE\Software\Microsoft\
Internet Explorer\PhishingFilter
HKEY_USERS\.DEFAULT\Software\
Microsoft\Internet Explorer\PhishingFilter
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Internet Explorer\PhishingFilter
Enabled = "0"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Internet Explorer\PhishingFilter
Enabled = "0"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
EnableFirewall = "0"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
EnableLUA = "0"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
zmlzjznrwjbjnuxczakhTaskMgr = "0"
Dropping Routine
This Trojan drops the following files:
- %System Root%\userid.dat
(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
Other Details
This Trojan connects to the following possibly malicious URL:
- http://www3.{BLOCKED}n.com/images/index.jpg?repeat=0&nocache=9354
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_CURRENT_USER\Software\Microsoft\Internet Explorer
- PhishingFilter
- In HKEY_LOCAL_MACHINE\Software\Microsoft\Internet Explorer
- PhishingFilter
- In HKEY_USERS\.DEFAULT\Software\Microsoft\Internet Explorer
- PhishingFilter
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies
- System
Step 3
Delete this 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\Internet Explorer\PhishingFilter
- Enabled = "0"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\PhishingFilter
- Enabled = "0"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
- EnableFirewall = "0"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
- EnableLUA = "0"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
- zmlzjznrwjbjnuxczakhTaskMgr = "0"
Step 4
Search and delete this file
- %System Root%\userid.dat
Step 5
Search and delete this folder
- %User Profile%\Application Data\MSA
Step 6
Scan your computer with your Trend Micro product to delete files detected as TROJ_VILSEL.SMD. 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 deleted/modified files and/or registry entries from backup
*Note: Only Microsoft-related files/keys/values will be restored. If this malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- %System%\wscntfy.exe
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