TrojanSpy.Win64.CRYPTWOFOUR.THGAHBE
Windows
Threat Type: Trojan Spy
Destructiveness: No
Encrypted:
In the wild: Yes
OVERVIEW
This Trojan Spy 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.
It gathers certain information on the affected computer.
TECHNICAL DETAILS
Arrival Details
This Trojan Spy 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 Spy drops the following files:
- %Temp%\test.txt → Contains the results of arbitrary command execution.
- %Temp%\tmp.bat → This file is created when the command execution method is set to 1.
(Note: %Temp% is the Windows temporary folder, where it usually is C:\Windows\Temp on all Windows operating system versions.)
It adds the following processes:
- cmd /c %Temp%\tmp.bat → This process is created when the command execution method is set to 1.
(Note: %Temp% is the Windows temporary folder, where it usually is C:\Windows\Temp on all Windows operating system versions.)
Backdoor Routine
This Trojan Spy executes the following commands from a remote malicious user:
- It executes arbitrary commands using the following method:
- 1 → Batch file execution
- Others → Direct Execution via Shell
Download Routine
This Trojan Spy connects to the following URL(s) to download its component file(s):
- https://www.{BLOCKED}apis.com/drive/v3/files/{file_id}
Information Theft
This Trojan Spy gathers the following information on the affected computer:
- Computer Name
- Username
Other Details
This Trojan Spy does the following:
- It will only proceed to its malicious routine if it is ran as a service.
- Captures all keyboard input.
- Captures clipboard data text changes.
- It generates a unique file name for executing victim-based arbitrary commands:
- {ComputerName}_{Username}_Test.txt
- It connects to the specified URL to upload the %Temp%\test.txt file:
- https://www.{BLOCKED}apis.com/upload/drive/v3/files?uploadType=multipart
- After command execution, the system reconnects to the specified URL to remove the file associated with the victim:
- https://www.{BLOCKED}apis.com/drive/v3/files/{file_id}
- It connects to the specified URL to search for the victim ID. This is done to retrieve the commands to be executed:
- https://www.{BLOCKED}apis.com/drive/v3/files?q=name='{Computer Name}_{Username}_Test.txt'
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.XXPE50FFF095
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
Search and delete this file
- %Temp%\test.txt
- %Temp%\tmp.bat
Step 5
Scan your computer with your Trend Micro product to delete files detected as TrojanSpy.Win64.CRYPTWOFOUR.THGAHBE. 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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