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.
It may be downloaded by the following malware/grayware from remote sites:
Installation
This Backdoor drops the following files:
- %All Users Profile%\AsusGesture\settings.dat
(Note: %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000, XP, and Server 2003, or C:\ProgramData on Windows Vista, 7, and 8. )
It drops and executes the following files:
- %User Temp%\Data1\TabSvc.exe
- %User Temp%\exit.exe -> executes i.cmd
- %User Temp%\i.cmd -> renames syst.dll to btc.exe
- %User Temp%\syst.dll (renamed to btc.exe)
- %All Users Profile%\AsusGesture\exit.exe -> executes i.cmd
- %All Users Profile%\AsusGesture\i.cmd
- %All Users Profile%\AsusGesture\winserv.exe -> detected as PUA.Win32.RManSys.AA
It creates the following folders:
- %User Temp%\Data1
- %All Users Profile%\AsusGesture
(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, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, and 8.. %All Users Profile% is the common user's profile folder, which is usually C:\Documents and Settings\All Users on Windows 2000, XP, and Server 2003, or C:\ProgramData on Windows Vista, 7, and 8. )
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
AsusGesture = %All Users Profile%\AsusGesture\winserv.exe
Backdoor Routine
This Backdoor connects to the following URL(s) to send and receive commands from a remote malicious user:
- {BLOCKED}.{BLOCKED}.{BLOCKED}.16:5655
Process Termination
This Backdoor terminates the following processes if found running in the affected system's memory:
Other Details
This Backdoor connects to the following URL(s) to check for an Internet connection:
It does the following:
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
Note that not all files, folders, and registry keys and entries are installed on your computer during this malware's/spyware's/grayware's execution. This may be due to incomplete installation or other operating system conditions. If you do not find the same files/folders/registry information, please proceed to the next step.
Step 3
Terminate a malware/grayware process
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*Note: If the detected process is not displayed in theWindows Task Manager, continue doing the next steps.
- %User Temp%\exit.exe
- %All Users Profile%\AsusGesture\exit.exe
- %User Temp%\i.cmd
- %All Users Profile%\AsusGesture\i.cmd
- %All Users Profile%\AsusGesture\winserv.exe
To terminate the malware/grayware process:
- Open Windows Task Manager. To do this, press CTRL+SHIFT+ESC.
- View the list of all running programs. To do this:
• For Windows 2000, XP, Server 2003, Vista, 7, and Server 2008 users, click the Processes tab.
• For Windows 8, 8.1, and Server 2012 users, click the Details tab. - In the list of running programs, locate the process:
- %User Temp%\exit.exe
- %All Users Profile%\AsusGesture\exit.exe
- %User Temp%\i.cmd
- %All Users Profile%\AsusGesture\i.cmd
- %All Users Profile%\AsusGesture\winserv.exe
- Select the process then press the End Process button.
- To check if the malware/grayware process/es has/have been terminated, close Windows Task Manager then open it again.
- Close Windows Task Manager.
Step 4
Delete this registry value
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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
- AsusGesture = %All Users Profile%\AsusGesture\winserv.exe
To delete the registry value this malware created:
- Open Registry Editor. To do this:
» For Windows 2000, Windows XP, and Windows Server 2003 users, click Start>Run, type regedit in the text box provided, and then press Enter.
» For Windows Vista, Windows 7, and Windows Server 2008 users, click the Start button, type regedit in the Search input field then press Enter.
» For Windows 8, Windows 8.1, and Windows Server 2012 users, right-click on the lower left corner of the screen, click Run, type regedit in the text box provided, and then press Enter. - In the left panel of the Registry Editor window, double-click the following:
HKEY_CURRENT_USER>Software>Microsoft>Windows>CurrentVersion>Run - In the right panel, locate and delete the entry:
AsusGesture = %All Users Profile%\AsusGesture\winserv.exe - Close Registry Editor.
Step 5
Search and delete these folders
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Please make sure you check the
Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
- %User Temp%\Data1
- %All Users Profile%\AsusGesture
To delete malware/grayware/spyware folders:
For Windows 2000, Windows XP, and Windows Server 2003:
- Right-click Start then click Search... or Find..., depending on the version of Windows you are running.
- In the File name* input box, type:
- %User Temp%\Data1
- %All Users Profile%\AsusGesture
- In the Look In drop-down list, select My Computer, then press Enter.
- Once located, select the folder then press SHIFT+DELETE to permanently delete the folder.
- Repeat steps 2 to 4 for the remaining folders:
- %User Temp%\Data1
- %All Users Profile%\AsusGesture
*Note: The file name input box title varies depending on the Windows version (e.g. Search for files or folders named or All or part of the file name.).
For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:
- Open a Windows Explorer window.
- For Windows Vista, 7, and Server 2008 users, click Start>Computer.
- For Windows 8, 8.1, and Server 2012 users, right-click on the lower left corner of the screen, then click File Explorer.
- In the Search Computer/This PC input box, type:
- %User Temp%\Data1
- %All Users Profile%\AsusGesture
- Once located, select the file then press SHIFT+DELETE to permanently delete the folder.
- Repeat steps 2-3 for the remaining folders:
- %User Temp%\Data1
- %All Users Profile%\AsusGesture
*Note: Read the following Microsoft page if these steps do not work on Windows 7.
Step 6
Search and delete this file
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There may be some files that are hidden. Please make sure you check the
Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
- %User Temp%\Data1\TabSvc.exe
- %User Temp%\exit.exe
- %User Temp%\i.cmd
- %User Temp%\syst.dll
- %User Temp%\btc.exe
- %All Users Profile%\AsusGesture\exit.exe
- %All Users Profile%\AsusGesture\i.cmd
- %All Users Profile%\AsusGesture\winserv.exe
- %All Users Profile%\AsusGesture\settings.dat
To manually delete a malware/grayware file from an affected system:
• For Windows 2000, Windows XP, and Windows Server 2003:
- Right-click Start then click Search....
- In the File name* input box, type the following:
- %User Temp%\Data1\TabSvc.exe
- %User Temp%\exit.exe
- %User Temp%\i.cmd
- %User Temp%\syst.dll
- %User Temp%\btc.exe
- %All Users Profile%\AsusGesture\exit.exe
- %All Users Profile%\AsusGesture\i.cmd
- %All Users Profile%\AsusGesture\winserv.exe
- %All Users Profile%\AsusGesture\settings.dat
- In the Look In drop-down list, select My Computer then press Enter.
- Once located, select the file then press SHIFT+DELETE to delete it.
*Note: The file name input box title varies depending on the Windows version (e.g. Search for files or folders named or All or part of the file name.).
• For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:
- Open a Windows Explorer window.
- For Windows Vista, 7, and Server 2008 users, click Start>Computer.
- For Windows 8, 8.1, and Server 2012 users, right-click on the lower left corner of the screen, then click File Explorer.
- In the Search Computer/This PC input box, type:
- %User Temp%\Data1\TabSvc.exe
- %User Temp%\exit.exe
- %User Temp%\i.cmd
- %User Temp%\syst.dll
- %User Temp%\btc.exe
- %All Users Profile%\AsusGesture\exit.exe
- %All Users Profile%\AsusGesture\i.cmd
- %All Users Profile%\AsusGesture\winserv.exe
- %All Users Profile%\AsusGesture\settings.dat
- Once located, select the file then press SHIFT+DELETE to delete it.
*Note: Read the following Microsoft page if these steps do not work on Windows 7.
Step 7
Scan your computer with your Trend Micro product to delete files detected as Backdoor.Win32.RMSRAT.THAABCAH. 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 the following Trend Micro Support pages for more information:
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