BKDR_TINPAD.A
Windows 2000, Windows XP, Windows Server 2003
![](/vinfo/imgFiles/legend.jpg)
Threat Type: Backdoor
Destructiveness: No
Encrypted: No
In the wild: Yes
OVERVIEW
Downloaded from the Internet, Dropped by other malware
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.
It executes commands from a remote malicious user, effectively compromising the affected system.
TECHNICAL DETAILS
135,168 bytes
EXE, DLL
Yes
11 Oct 2012
Compromises system security, Steals information, Drops files
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.
Installation
This backdoor drops the following component file(s):
- %User Temp%\$MsAutoUpdate.exe - also detected as BKDR_TINPAD.A
- %User Temp%\load.dat - also detected as BKDR_TINPAD.A
- %Windows%\ernel32.dll - also detected as BKDR_TINPAD.A
- %Windows%\thumb.db - also detected as BKDR_TINPAD.A
- All Users' %User Profile%\svchost.exe - also detected as BKDR_TINPAD.A
(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.. %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %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.)
It drops the following non-malicious file:
- %User Temp%\{malware's file name less 4 characters} - decoy .PDF file
(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.)
Its DLL component is injected to the following process(es):
- explorer.exe
- iexplore.exe
- taskmgr.exe
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- thinkpad
- IDll
Autostart Technique
This backdoor adds the following registry entries to enable its automatic execution at every system startup:
HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
winsupdate = "All Users' %User Profile%\svchost.exe"
HKEY_CURRENT_USER\Software\Microsoft\
Windows NT\CurrentVersion\Windows
run = "All Users' %User Profile%\svchost.exe"
Backdoor Routine
This backdoor executes the following commands from a remote malicious user:
- Create a process
- Enumerate running processes
- Get process information
- Terminate a process
- Enumerate files and folders
- Get drive information
- Get file information
- Create a folder
- Delete a file/folder
- Move a file/folder
- Upload a file to C&C server
- Download a file from C&C server
- Execute a file
- Perform remote shell
- Take a screenshot
- Perform port mapping
It connects to the following URL(s) to send and receive commands from a remote malicious user:
- {BLOCKED}dated.dyndns.org
It posts the following information to its command and control (C&C) server:
- Computer name
- Local IP address
- OS version information
- Processor information
- RAM information
- User name
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
Restart in Safe Mode
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\Microsoft\Windows\CurrentVersion\Run
- winsupdate = "All Users' %User Profile%\svchost.exe"
- winsupdate = "All Users' %User Profile%\svchost.exe"
- In HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
- run = "All Users' %User Profile%\svchost.exe"
- run = "All Users' %User Profile%\svchost.exe"
Step 4
Search and delete these files
- %User Temp%\{malware's file name less 4 characters}
Step 5
Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_TINPAD.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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