TROJ_ZLOB.CQL
Trojan.Zlob (Symantec); Trojan-Downloader.Win32.Zlob.eie (Kaspersky); Trojan.DNSChanger.Gen (Sunbelt); Trojan.Zlob.56589 (FSecure)
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
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
73,251 bytes
EXE
No
03 Oct 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:
- %System Root%\DOCUME~1
- %System Root%\DOCUME~1\Wilbert
- %User Profile%\LOCALS~1
- %User Temp%\nsr2.tmp
- %Program Files%\XXXPlugin
- %System Root%\Documents and Settings\Wilbert
- %Start Menu%\Programs\XXXPlugin
(Note: %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.. %Program Files% is the default Program Files folder, usually C:\Program Files.. %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Profiles\{user name}\Start Menu on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu on Windows NT and C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003.)
Other System Modifications
This Trojan deletes the following files:
- %User Temp%\nsm1.tmp
- %User Temp%\nsr2.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_CURRENT_USER\Software\XXXPlugin
HKEY_CLASSES_ROOT\XXXPlugin\CLSID
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows\CurrentVersion\Uninstall\
XXXPlugin
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
XXXPlugin
UninstallString = "%Program Files%\XXXPlugin\Uninstall.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
XXXPlugin
InstallLocation = "%Program Files%\XXXPlugin"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
XXXPlugin
DisplayName = "XXXPlugin"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
XXXPlugin
DisplayIcon = "%Program Files%\XXXPlugin\Uninstall.exe,0"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
XXXPlugin
NoModify = "1"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Uninstall\
XXXPlugin
NoRepair = "1"
HKEY_CURRENT_USER\Software\XXXPlugin
Start Menu Folder = "XXXPlugin"
Dropping Routine
This Trojan drops the following files:
- %User Temp%\nsr2.tmp\modern-header.bmp
- %Program Files%\XXXPlugin\Uninstall.exe
- %Start Menu%\Programs\XXXPlugin\Uninstall.lnk
- %User Temp%\nsr2.tmp\StartMenu.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.. %Start Menu% is the current user's Start Menu folder, which is usually C:\Windows\Profiles\{user name}\Start Menu on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu on Windows NT and C:\Windows\Start Menu or C:\Documents and Settings\{User name}\Start Menu on Windows 2000, XP, and Server 2003.)
This report is generated via an automated analysis system.
SOLUTION
9.200
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_CURRENT_USER\Software
- XXXPlugin
- In HKEY_CLASSES_ROOT\XXXPlugin
- CLSID
- In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall
- XXXPlugin
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\XXXPlugin
- UninstallString = "%Program Files%\XXXPlugin\Uninstall.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\XXXPlugin
- InstallLocation = "%Program Files%\XXXPlugin"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\XXXPlugin
- DisplayName = "XXXPlugin"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\XXXPlugin
- DisplayIcon = "%Program Files%\XXXPlugin\Uninstall.exe,0"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\XXXPlugin
- NoModify = "1"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\XXXPlugin
- NoRepair = "1"
- In HKEY_CURRENT_USER\Software\XXXPlugin
- Start Menu Folder = "XXXPlugin"
Step 4
Search and delete these files
- %User Temp%\nsr2.tmp\modern-header.bmp
- %Program Files%\XXXPlugin\Uninstall.exe
- %Start Menu%\Programs\XXXPlugin\Uninstall.lnk
- %User Temp%\nsr2.tmp\StartMenu.dll
Step 5
Search and delete these folders
- %System Root%\DOCUME~1
- %System Root%\DOCUME~1\Wilbert
- %User Profile%\LOCALS~1
- %User Temp%\nsr2.tmp
- %Program Files%\XXXPlugin
- %System Root%\Documents and Settings\Wilbert
- %Start Menu%\Programs\XXXPlugin
Step 6
Scan your computer with your Trend Micro product to delete files detected as TROJ_ZLOB.CQL. 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%\nsm1.tmp
- %User Temp%\nsr2.tmp
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