TROJ_DROPPR.EBF
Dagis (McAfee); Trojan Horse (Symantec); Trojan.Win32.Agent.agj (Kaspersky); BehavesLike.Win32.Malware.eah (mx-v) (Sunbelt); Trojan horse Generic3.ADD (AVG)
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.
It disables Task Manager, Registry Editor, and Folder Options.
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.
Autostart Technique
This Trojan adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
WindowsControl = "%System%\wctrl.exe"
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
winampa = "%System%\winampa.exe"
Other System Modifications
This Trojan adds the following registry keys:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
It modifies the following registry entries:
HKEY_CURRENT_USER\Control Panel\Desktop
SCRNSAVE.EXE = "%Windows%\GADISS~1.SCR"
(Note: The default value data of the said registry entry is %Windows%\system32\logon.scr.)
It creates the following registry entry(ies) to disable Task Manager, Registry Tools and Folder Options:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableRegistryTools = "1"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
System
DisableTaskMgr = "1"
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Policies\
Explorer
NoFolderOptions = "1"
Dropping Routine
This Trojan drops the following files:
- %System%\winampa.exe
- %System%\wctrl.exe
- %System%\Gadis Seksi.scr
- %Windows%\update2
- %Windows%\fc2
- %System Root%\bo2
- E:\bo2
- F:\bo2
- G:\bo2
- H:\bo2
- I:\bo2
- J:\bo2
- K:\bo2
- L:\bo2
- M:\bo2
- N:\bo2
- O:\bo2
- P:\bo2
- Q:\bo2
- R:\bo2
- S:\bo2
- T:\bo2
- U:\bo2
- V:\bo2
- W:\bo2
- X:\bo2
- Y:\bo2
- Z:\bo2
(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.. %Windows% is the Windows folder, which is usually C:\Windows.. %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)
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
Restart in Safe Mode
Step 3
Enable Registry Editor, Task Manager, and Folder options
Step 4
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\Windows\CurrentVersion\Policies
- System
Step 5
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\CurrentVersion\Run
- WindowsControl = "%System%\wctrl.exe"
- In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
- winampa = "%System%\winampa.exe"
Step 6
Restore these modified registry values
Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.
- In HKEY_CURRENT_USER\Control Panel\Desktop
- From: SCRNSAVE.EXE = "%Windows%\GADISS~1.SCR"
To: SCRNSAVE.EXE = ""%Windows%\system32\logon.scr""
- From: SCRNSAVE.EXE = "%Windows%\GADISS~1.SCR"
Step 7
Search and delete these components
- %System%\winampa.exe
- %System%\wctrl.exe
- %System%\Gadis Seksi.scr
- %Windows%\update2
- %Windows%\fc2
- %System Root%\bo2
- E:\bo2
- F:\bo2
- G:\bo2
- H:\bo2
- I:\bo2
- J:\bo2
- K:\bo2
- L:\bo2
- M:\bo2
- N:\bo2
- O:\bo2
- P:\bo2
- Q:\bo2
- R:\bo2
- S:\bo2
- T:\bo2
- U:\bo2
- V:\bo2
- W:\bo2
- X:\bo2
- Y:\bo2
- Z:\bo2
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_DROPPR.EBF. 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.
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