TROJ_ZLOB.JG
TrojanDownloader:Win32/Zlob.gen!AL (Microsoft); Puper (McAfee); Trojan.Zlob (Symantec); ARC:NSIS, [$PLUGINSDIR\barf.dll]:Trojan-Downloader.Win32.Zlob.fvw (Kaspersky); Trojan-Downloader.Zlob.Media-Codec (Sunbelt); Dropped:Trojan.Downloader.Zlob.ABGS (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
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%\nsw3.tmp
- %Program Files%\Video Add-on
(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.)
Other System Modifications
This Trojan deletes the following files:
- %User Temp%\nsh1.tmp
- %User Temp%\nsw3.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\Online Add-on
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Online Add-on
Type = "3"
HKEY_CURRENT_USER\Software\Online Add-on
Path = "%Program Files%\Video Add-on"
HKEY_CURRENT_USER\Software\Online Add-on
Removable = "0"
Dropping Routine
This Trojan drops the following files:
- %User Temp%\nsw2.tmp
- %User Temp%\nsw3.tmp\reuninstall.ini
- %User Temp%\nsw3.tmp\ioSpecial.ini
- %User Temp%\nsw3.tmp\modern-wizard.bmp
- %User Temp%\nsw3.tmp\modern-header.bmp
- %User Temp%\nsw3.tmp\barf.dll
- %User Temp%\laf0.exe
(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.)
Other Details
This Trojan connects to the following possibly malicious URL:
- http://{BLOCKED}164.54/games/action/release/install.php?param=0;1187;1110
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_CURRENT_USER\Software
- Online Add-on
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\Online Add-on
- Type = "3"
- In HKEY_CURRENT_USER\Software\Online Add-on
- Path = "%Program Files%\Video Add-on"
- In HKEY_CURRENT_USER\Software\Online Add-on
- Removable = "0"
Step 4
Search and delete these files
- %User Temp%\nsw2.tmp
- %User Temp%\nsw3.tmp\reuninstall.ini
- %User Temp%\nsw3.tmp\ioSpecial.ini
- %User Temp%\nsw3.tmp\modern-wizard.bmp
- %User Temp%\nsw3.tmp\modern-header.bmp
- %User Temp%\nsw3.tmp\barf.dll
- %User Temp%\laf0.exe
Step 5
Search and delete these folders
- %System Root%\DOCUME~1
- %System Root%\DOCUME~1\Wilbert
- %User Profile%\LOCALS~1
- %User Temp%\nsw3.tmp
- %Program Files%\Video Add-on
Step 6
Scan your computer with your Trend Micro product to delete files detected as TROJ_ZLOB.JG. 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%\nsh1.tmp
- %User Temp%\nsw3.tmp
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