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.
Installation
This Trojan creates the following folders:
(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.)
Autostart Technique
This Trojan registers as a system service to ensure its automatic execution at every system startup by adding the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
Other System Modifications
This Trojan deletes the following files:
- %User Temp%\$inst\0.tmp
- %User Temp%\$inst\1.tmp
- %User Temp%\$inst\2.tmp
- %User Temp%\$inst\3.tmp
- %User Temp%\$inst\4.tmp
- %User Temp%\$inst\5.tmp
- %User Temp%\$inst\6.tmp
- %User Temp%\$inst\7.tmp
- %User Temp%\$inst\8.tmp
- %User Temp%\$inst\9.tmp
- %User Temp%\$inst\10.tmp
- %User Temp%\$inst\11.tmp
- %User Temp%\$inst\12.tmp
- %System%\R_INST~1.BAT
(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.. %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
It deletes the following folders:
(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.)
It adds the following registry keys:
HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\
v2.0\Server\NtUsers
HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\
v2.0\Server\Parameters
It adds the following registry entries:
HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\
v2.0\Server\NtUsers
1 = {random values}
HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\
v2.0\Server\Parameters
NTAuthEnabled = {random values}
HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\
v2.0\Server\Parameters
Parameter = {random values}
HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\
v2.0\Server\Parameters
Port = {random values}
HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\
v2.0\Server\Parameters
Timeout = {random values}
HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\
v2.0\Server\Parameters
EnableLogFile = {random values}
HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\
v2.0\Server\Parameters
LogFilePath = "%System%\logfile.txt"
HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\
v2.0\Server\Parameters
FilterIp = {random values}
HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\
v2.0\Server\Parameters
DisableTrayIcon = {random values}
HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\
v2.0\Server\Parameters
AutoAllow = {random values}
HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\
v2.0\Server\Parameters
AskUser = {random values}
HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\
v2.0\Server\Parameters
EnableEventLog = {random values}
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile
EnableFirewall = 1
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\GloballyOpenPorts\
List
4899:TCP = "4899:TCP:*:Enabled:systerm"
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%System%\r_server.exe = "%System%\r_server.exe:*:Enabled:systerm"
Dropping Routine
This Trojan drops the following files:
- %System%\r_server.exe
- %System%\r_install.bat
(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)
This report is generated via an automated analysis system.
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
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To restart in Safe Mode:
• For Windows 2000 users
- Restart your computer.
- Press F8 when you see the Starting Windows bar at the bottom of the screen.
- Choose the Safe Mode option from the Windows Advanced Options menu then press Enter.
• For Windows XP users
- Restart your computer.
- Press F8 after the Power-On Self Test (POST) routine is done. If the Windows Advanced Options menu does not appear, try restarting then pressing F8 several times when the POST screen appears.
- Choose the Safe Mode option from the Windows Advanced Options menu then press Enter.
• For Windows Server 2003 users
- Restart your computer.
- Press F8 after Windows starts up. If the Windows Advanced Options menu does not appear, try restarting again and pressing F8 several times afterward.
- On the Windows Advanced Option menu, use the arrow keys to select Safe Mode then press Enter.
Step 3
Delete this registry key
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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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts
- In HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\v2.0\Server
- In HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\v2.0\Server
To delete the registry key this malware/grayware created:
- Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
- In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SYSTEM>CurrentControlSet>Services>SharedAccess>Parameters>FirewallPolicy>StandardProfile>GloballyOpenPorts - Still in the left panel, locate and delete the key:
List - In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SYSTEM>RAdmin>v2.0>Server - Still in the left panel, locate and delete the key:
NtUsers - Again Still in the left panel, locate and delete the key:
Parameters - Close Registry Editor.
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_LOCAL_MACHINE\SYSTEM\RAdmin\v2.0\Server\NtUsers
- In HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\v2.0\Server\Parameters
- NTAuthEnabled={random values}
- In HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\v2.0\Server\Parameters
- Parameter={random values}
- In HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\v2.0\Server\Parameters
- In HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\v2.0\Server\Parameters
- In HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\v2.0\Server\Parameters
- EnableLogFile={random values}
- In HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\v2.0\Server\Parameters
- LogFilePath="%System%\logfile.txt"
- In HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\v2.0\Server\Parameters
- In HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\v2.0\Server\Parameters
- DisableTrayIcon={random values}
- In HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\v2.0\Server\Parameters
- AutoAllow={random values}
- In HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\v2.0\Server\Parameters
- In HKEY_LOCAL_MACHINE\SYSTEM\RAdmin\v2.0\Server\Parameters
- EnableEventLog={random values}
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\GloballyOpenPorts\List
- 4899:TCP="4899:TCP:*:Enabled:systerm"
- In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
- %System%\r_server.exe="%System%\r_server.exe:*:Enabled:systerm"
To delete the registry value this malware/grayware created:
- Open Registry Editor. Click Start>Run, type REGEDIT, then press Enter.
- In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SYSTEM>RAdmin>v2.0>Server>NtUsers - In the right panel, locate and delete the entry:
1 = {random values} - In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SYSTEM>RAdmin>v2.0>Server>Parameters - In the right panel, locate and delete the entry:
NTAuthEnabled = {random values} - Again In the right panel, locate and delete the entry:
Parameter = {random values} - Again In the right panel, locate and delete the entry:
Port = {random values} - Again In the right panel, locate and delete the entry:
Timeout = {random values} - Again In the right panel, locate and delete the entry:
EnableLogFile = {random values} - Again In the right panel, locate and delete the entry:
LogFilePath = "%System%\logfile.txt" - Again In the right panel, locate and delete the entry:
FilterIp = {random values} - Again In the right panel, locate and delete the entry:
DisableTrayIcon = {random values} - Again In the right panel, locate and delete the entry:
AutoAllow = {random values} - Again In the right panel, locate and delete the entry:
AskUser = {random values} - Again In the right panel, locate and delete the entry:
EnableEventLog = {random values} - In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SYSTEM>ControlSet001>Services>SharedAccess>Parameters>FirewallPolicy>StandardProfile - In the right panel, locate and delete the entry:
EnableFirewall = 1 - In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SYSTEM>ControlSet001>Services>SharedAccess>Parameters>FirewallPolicy>StandardProfile>GloballyOpenPorts>List - In the right panel, locate and delete the entry:
4899:TCP = "4899:TCP:*:Enabled:systerm" - In the left panel, double-click the following:
HKEY_LOCAL_MACHINE>SYSTEM>ControlSet001>Services>SharedAccess>Parameters>FirewallPolicy>StandardProfile>AuthorizedApplications>List - In the right panel, locate and delete the entry:
%System%\r_server.exe = "%System%\r_server.exe:*:Enabled:systerm" - Close Registry Editor.
Step 5
Search and delete this folder
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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%\$inst
To delete the malware/grayware folder:
- Right-click Start then click Search... or Find..., depending on the version of Windows you are running.
- In the Named input box, type:
- 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.
Step 6
Search and delete these files
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There may be some component 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.
- %System%\r_server.exe
- %System%\r_install.bat
To delete malware/grayware component files:
- Search for the following files:
- %System%\r_server.exe
- %System%\r_install.bat
Note: To do a search for the following files, right-click Start then click Search... or Find..., depending on the version of Windows you are running. For each file to be deleted, type its file name in the Named input box. In the Look In drop-down list, select My Computer, then press Enter. - Once located, select the file then press SHIFT+DELETE to permanently delete the file.
- Repeat the said steps for all files listed.
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_DLOADER.ROS. 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 8
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 Temp%\$inst\0.tmp
- %User Temp%\$inst\1.tmp
- %User Temp%\$inst\2.tmp
- %User Temp%\$inst\3.tmp
- %User Temp%\$inst\4.tmp
- %User Temp%\$inst\5.tmp
- %User Temp%\$inst\6.tmp
- %User Temp%\$inst\7.tmp
- %User Temp%\$inst\8.tmp
- %User Temp%\$inst\9.tmp
- %User Temp%\$inst\10.tmp
- %User Temp%\$inst\11.tmp
- %User Temp%\$inst\12.tmp
- %System%\R_INST~1.BAT
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