Backdoor.Win32.REMCOS.USMANEAGGD
Backdoor:Win32/Remcos.A!MTB (MICROSOFT); Backdoor.Remcos (IKARUS)
Windows
Threat Type: Backdoor
Destructiveness: No
Encrypted: No
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.
It executes commands from a remote malicious user, effectively compromising the affected system.
However, as of this writing, the said sites are inaccessible.
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 drops the following files:
- %User Temp%\uninstall.vbs
- %User Temp%\restart.vbs
- %User Temp%\update.vbs
(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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
It adds the following processes:
- %User Temp%\uninstall.vbs
(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(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- Remcos-HP2YO7
Other System Modifications
This Backdoor adds the following registry entries:
HKEY_CURRENT_USER\Software\Remcos-HP2YO7
licence = {Random}
HKEY_CURRENT_USER\Software\Remcos-HP2YO7
pth_unenc = {Malware File Path}\{Malware Filename}.exe
HKEY_CURRENT_USER\Software\Remcos-HP2YO7
v = 2.4.7 Light
Backdoor Routine
This Backdoor executes the following commands from a remote malicious user:
- Change Desktop Wallpaper
- Create Directory
- Open Directory
- Browse Directories
- Delete Directory
- Open File
- Read Files
- Rename File
- Delete File
- Download File
- Upload File
- Create File
- Execute Files
- Execute Shell Command
- Open Command Prompt
- Copy and Paste Text To and From Clipboard
- Play, Pause, and Stop Audio
- Play Alarm
- Display a Window
- Close a Window
- Terminate Process
- Load and Save Image
- Empty Clipboard Data
- Get Active Program's Window Title
It connects to the following URL(s) to send and receive commands from a remote malicious user:
- {BLOCKED}shelp1234.{BLOCKED}s.org
Information Theft
This Backdoor gathers the following data:
- Windows Version
- System Type (x32, x64)
- User Privilege (is admin or not)
- Computer Name
- Username
- Computer Memory Information (Physical and Virtual)
- Drive Information/Types
- Mouse Clicks
- Keyboard Input
- User Profile
- Processor Architecture
- Locale Info
Other Details
This Backdoor adds the following registry keys:
HKEY_CURRENT_USER\Software\Remcos-HP2YO7
However, as of this writing, the said sites are inaccessible.
SOLUTION
Step 1
Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:
- Troj.Win32.TRX.XXPE50FFF034
Step 2
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 3
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 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\Remcos-HP2YO7
- licence = {Random}
- licence = {Random}
- In HKEY_CURRENT_USER\Software\Remcos-HP2YO7
- pth_unenc = {Malware File Path}\{Malware Filename}.exe
- pth_unenc = {Malware File Path}\{Malware Filename}.exe
- In HKEY_CURRENT_USER\Software\Remcos-HP2YO7
- v = 2.4.7 Light
- v = 2.4.7 Light
Step 5
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.
- HKEY_CURRENT_USER\Software\Remcos-HP2YO7
Step 6
Search and delete this file
- %User Temp%\uninstall.vbs
- %User Temp%\restart.vbs
- %User Temp%\update.vbs
Step 7
Scan your computer with your Trend Micro product to delete files detected as Backdoor.Win32.REMCOS.USMANEAGGD. 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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