TROJ_DROPPR.GDF
Trojan:Win32/Malagent!gmb (Microsoft); Trojan.Win32.Yakes.fsks (Kaspersky); Troj/Ranybus-A (Sophos); Trojan.Win32.Generic!BT (Sunbelt); Trojan horse PSW.Generic12.ATTF (AVG)
Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)
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 disables Task Manager, Registry Editor, and Folder Options.
It deletes itself after execution.
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.
Other System Modifications
This Trojan deletes the following files:
- %User Profile%\Cookies\index.dat
- %User Profile%\Cookies\wilbert@atdmt[2].txt
- %User Profile%\Cookies\wilbert@bing[2].txt
- %User Profile%\Cookies\wilbert@c.atdmt[2].txt
- %User Profile%\Cookies\wilbert@c.msn[2].txt
- %User Profile%\Cookies\wilbert@doubleclick[1].txt
- %User Profile%\Cookies\wilbert@microsoft[1].txt
- %User Profile%\Cookies\wilbert@msnportal.112.2o7[1].txt
- %User Profile%\Cookies\wilbert@msn[2].txt
- %User Profile%\Cookies\wilbert@scorecardresearch[2].txt
- %User Profile%\Cookies\wilbert@www.bing[2].txt
- %User Profile%\Cookies\wilbert@www.msn[1].txt
It adds the following registry keys:
HKEY_CURRENT_USER\wK³\{random key}
HKEY_USERS\S-1-5-21-1645522239-1292428093-682003330-1003\Software\
Microsoft\Windows\CurrentVersion\
policies\Explorer\Run
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Winlogon
SysDebug32 = "{random values}"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%System%\svchost.exe = "%System%\svchost.exe:*:Enabled:Lub_KpCexWpDXbvcLulkwVCaLz"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
Lub_KpCexWpDXbvcLulkwVCaLz = "ffffffff"
It creates the following registry entry(ies) to disable Task Manager, Registry Tools and Folder Options:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer\Run
Lub_KpCexWpDXbvcLulkwVCaLz = "%System%\OSDIoNByCDRgSS.exe"
It deletes the following registry keys:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows NT\CurrentVersion\SystemRestore
Dropping Routine
This Trojan drops the following files:
- %System%\OSDIoNByCDRgSS.exe
- %User Startup%\System Check.lnk
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %User Startup% is the current user's Startup folder, which is usually C:\Windows\Profiles\{user name}\Start Menu\Programs\Startup on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Start Menu\Programs\Startup on Windows NT, and C:\Documents and Settings\{User name}\Start Menu\Programs\Startup.)
Other Details
This Trojan connects to the following possibly malicious URL:
- http://{BLOCKED}4l.org
- {BLOCKED}.158.236
It deletes itself after execution.
This report is generated via an automated analysis system.
SOLUTION
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
Enable Registry Editor, Task Manager, and Folder options
Step 3
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\wK³
- {random key}
- In HKEY_USERS\S-1-5-21-1645522239-1292428093-682003330-1003\Software\Microsoft\Windows\CurrentVersion\policies\Explorer
- Run
Step 4
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\Windows NT\CurrentVersion\Winlogon
- SysDebug32 = "{random values}"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
- %System%\svchost.exe = "%System%\svchost.exe:*:Enabled:Lub_KpCexWpDXbvcLulkwVCaLz"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
- Lub_KpCexWpDXbvcLulkwVCaLz = "ffffffff"
Step 5
Search and delete these components
- %System%\OSDIoNByCDRgSS.exe
- %User Startup%\System Check.lnk
Step 6
Scan your computer with your Trend Micro product to delete files detected as TROJ_DROPPR.GDF. 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 Profile%\Cookies\index.dat
- %User Profile%\Cookies\wilbert@atdmt[2].txt
- %User Profile%\Cookies\wilbert@bing[2].txt
- %User Profile%\Cookies\wilbert@c.atdmt[2].txt
- %User Profile%\Cookies\wilbert@c.msn[2].txt
- %User Profile%\Cookies\wilbert@doubleclick[1].txt
- %User Profile%\Cookies\wilbert@microsoft[1].txt
- %User Profile%\Cookies\wilbert@msnportal.112.2o7[1].txt
- %User Profile%\Cookies\wilbert@msn[2].txt
- %User Profile%\Cookies\wilbert@scorecardresearch[2].txt
- %User Profile%\Cookies\wilbert@www.bing[2].txt
- %User Profile%\Cookies\wilbert@www.msn[1].txt
Step 8
Restore these deleted registry keys/values from backup
*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.
- In HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion
- SystemRestore
Did this description help? Tell us how we did.