Backdoor.Win32.REMCOS.USMANEAGIB
Backdoor:Win32/Rescoms (Microsoft); Win32:RemcosRAT-A [Trj] (Avast)
Windows
Threat Type: Backdoor
Destructiveness: No
Encrypted:
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
94,208 bytes
EXE
23 Nov 2020
Drops files, Connects to URLs/IPs, Steals information, Downloads files, Deletes files, Terminates processes, Logs keystrokes, Displays message/message boxes, Collects system information
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:
- %Application Data%\odum\logs.dat ? contains the information stolen from the victim
(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:
- %Application Data%\odum
(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 adds the following mutexes to ensure that only one of its copies runs at any one time:
- odum_oglqgonkvj
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
remcos = \remcos.exe
Other System Modifications
This Backdoor adds the following registry entries:
HKEY_Current_User\Software\odum_oglqgonkvj
EXEpath = {HEX DATA}
Backdoor Routine
This Backdoor executes the following commands from a remote malicious user:
- Activate Keylogger
- Capture Image
- Copy and paste text to and from clipboard
- Download Files
- Ping an address
- Send keyboard/mouse input
- Open the command prompt
- Open the event viewer
- Execute shell commands
- Execute files
- Browse directories
- Obtain file/directory attributes
- Change victim's Wallpaper
- Upload files
- Rename files
- Delete files
- Delete Directories
- Get screenshot
- Terminate processes
- Play/record audio
- Copy and paste text to and from clipboard
- Clear Browser login and cookies
- Perform registry changes
- Play alarm
- Display a messagebox
- Sends keyboard input
- Sends mouse click
- Retrieve logins and cookies from the following browsers:
- Google Chrome
- Mozilla Firefox
- Internet Explorer
It connects to the following URL(s) to send and receive commands from a remote malicious user:
- {BLOCKED}.{BLOCKED}.225.50:42025
Information Theft
This Backdoor gathers the following data:
- Product Name
- User Privilege (is admin or not)
- Locale Info
- Windows Version
- System Type (x32, x64)
- User keystrokes
- Clipboard Data
- User Activity (Idle time)
- User Name
- Computer Name
Other Details
This Backdoor adds the following registry keys:
HKEY_Current_User\Software\odum_oglqgonkvj
SOLUTION
9.800
16.392.05
04 Dec 2020
16.393.00
05 Dec 2020
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.XXPE50FFF038
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
Restart in Safe Mode
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\odum_oglqgonkvj
- EXEpath = {HEX DATA}
- EXEpath = {HEX DATA}
- In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
- remcos = \remcos.exe
- remcos = \remcos.exe
Step 6
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\odum_oglqgonkvjStep 7
Search and delete this file
Step 8
Search and delete these folders
Step 9
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Backdoor.Win32.REMCOS.USMANEAGIB . 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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