BKDR_CLIPDROP.A
Trojan.ADH (Symantec); Backdoor.Win32.Hupigon.sxlg (Kaspersky); Trojan.Win32.Generic.pak!cobra (Sunbelt); Found Luhe.Fiha.C (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: Backdoor
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This backdoor 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 backdoor 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 backdoor modifies the following registry entries to ensure it automatic execution at every system startup:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Userinit = "{random characters}"
(Note: The default value data of the said registry entry is %Windows%\system32\userinit.exe,.)
Other System Modifications
This backdoor adds the following registry keys:
HKEY_CURRENT_USER\Software\WinRAR SFX
HKEY_LOCAL_MACHINE\SOFTWARE\Adobe\
RemoteNotes
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Control\MediaResources\msvideo
It adds the following registry entries:
HKEY_CURRENT_USER\Software\WinRAR SFX
C%%Program Files%Windows NT% = "%Program Files%\Windows NT"
Dropping Routine
This backdoor drops the following files:
- __tmp_rar_sfx_access_check_66000
- demo.mp4
- urls.xml
- FreeJapanAV.ini
- InstallShield.xml
- FreeJapanAV.exe
- %Common Startup%\demo.mp4
- %Program Files%\Windows Media Player\rcimlby.exe
- %Program Files%\Common Files\Microsoft Shared\MSINFO\rcimlby.exe
(Note: %Common Startup% is the system's shared Startup folder, which is usually C:\Documents and Settings\All Users\Start Menu\Programs\Startup on Windows 2000, XP, and Server 2003.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)
Other Details
This backdoor connects to the following possibly malicious URL:
- {BLOCKED}.219.77
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
Identify and delete files detected as BKDR_CLIPDROP.A using either the Startup Disk or Recovery Console
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\Software
- WinRAR SFX
- In HKEY_LOCAL_MACHINE\SOFTWARE\Adobe
- RemoteNotes
- In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\MediaResources
- msvideo
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\WinRAR SFX
- C%%Program Files%Windows NT% = "%Program Files%\Windows NT"
Step 5
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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
- From: Userinit = "{random characters}"
To: Userinit = ""%Windows%\system32\userinit.exe,""
- From: Userinit = "{random characters}"
Step 6
Search and delete these components
- __tmp_rar_sfx_access_check_66000
- demo.mp4
- urls.xml
- FreeJapanAV.ini
- InstallShield.xml
- FreeJapanAV.exe
- %Common Startup%\demo.mp4
- %Program Files%\Windows Media Player\rcimlby.exe
- %Program Files%\Common Files\Microsoft Shared\MSINFO\rcimlby.exe
Step 7
Scan your computer with your Trend Micro product to delete files detected as BKDR_CLIPDROP.A. 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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