Backdoor.Win32.REMCOS.USMANEAGDS
Trojan-Dropper.Win32.Dapato.pzis (Kaspersky)
Windows
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.
Installation
This Backdoor adds the following processes:
- "%System%\WScript.exe" "%Application Data%\Jndos.vbs"
- %Application Data%\Jndos.vbs
- "%Application Data%\Rtktvf.exe"
- Rtktvf.exe
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
It creates the following folders:
- %AppDataLocal%\Rtk
- %User Profile%\Music
- %System Root%\Users
- %User Profile%\AppData
(Note: %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name} on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %System Root% is the Windows root folder, where it usually is C:\ on all Windows operating system versions.)
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
Rtk = "%AppDataLocal%\Rtk\Rtkos.vbs"
Other System Modifications
This Backdoor adds the following registry keys:
HKEY_CURRENT_USER\Software\Remcos-GE33SV
It adds the following registry entries:
HKEY_CURRENT_USER\Software\Remcos-GE33SV
exepath = "{random characters}"
HKEY_CURRENT_USER\Software\Remcos-GE33SV
licence = "292D5CDAF80B27EE076318CA523C73DA"
Dropping Routine
This Backdoor drops the following files:
- %Application Data%\Rtktvf.exe
- %AppDataLocal%\Rtk\Rtkna.bat
- %Application Data%\Rtk.bmp
- %AppDataLocal%\Rtk\Rtkos.vbs
- %Application Data%\Jndos.vbs
- %User Profile%\Music\Rtk.bmp
- %User Profile%\Music\Rtkwek.exe
- %Application Data%\Rtk.ocx
(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Roaming on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %AppDataLocal% is the Local Application Data folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Application Data on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).. %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name} on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
Other Details
This Backdoor connects to the following possibly malicious URL:
- http://blessederic.{BLOCKED}s.net
This report is generated via an automated analysis system.
SOLUTION
Step 1
Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.
Step 2
Restart in Safe Mode
Step 3
Identify and terminate files detected as Backdoor.Win32.REMCOS.USMANEAGDS
- Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
- If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
- If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.
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
- Remcos-GE33SV
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
- Rtk = "%AppDataLocal%\Rtk\Rtkos.vbs"
- In HKEY_CURRENT_USER\Software\Remcos-GE33SV
- exepath = "{random characters}"
- In HKEY_CURRENT_USER\Software\Remcos-GE33SV
- licence = "292D5CDAF80B27EE076318CA523C73DA"
Step 6
Search and delete these components
- %Application Data%\Rtktvf.exe
- %AppDataLocal%\Rtk\Rtkna.bat
- %Application Data%\Rtk.bmp
- %AppDataLocal%\Rtk\Rtkos.vbs
- %Application Data%\Jndos.vbs
- %User Profile%\Music\Rtk.bmp
- %User Profile%\Music\Rtkwek.exe
- %Application Data%\Rtk.ocx
Step 7
Search and delete these folders
- %AppDataLocal%\Rtk
- %User Profile%\Music
- %System Root%\Users
- %User Profile%\AppData
Step 8
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Backdoor.Win32.REMCOS.USMANEAGDS. 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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