TROJ_SHELLINJCT.A
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted: Yes
In the wild: Yes
OVERVIEW
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.
It uses the system's central processing unit (CPU) and/or graphical processing unit (GPU) resources to mine cryptocurrency.
TECHNICAL DETAILS
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 drops the following files:
- %Application Data%\appinit.bat → Deleted afterwards.
(Note: %Application Data% is the Application Data folder, where it usually is C:\Documents and Settings\{user name}\Application Data on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Roaming on Windows Vista (32- and 64-bit), Windows 7 (32- and 64-bit), Windows 8 (32- and 64-bit), Windows 8.1 (32- and 64-bit), Windows Server 2008, and Windows Server 2012.)
It adds the following mutexes to ensure that only one of its copies runs at any one time:
- Global\m_mutex_x
It injects codes into the following process(es):
- svchost.exe
Autostart Technique
The scheduled task executes the malware every:
- System startup
Process Termination
This Trojan terminates the following processes if found running in the affected system's memory:
- taskmgr.exe
Other Details
This Trojan does the following:
- It executes and injects the mining procedure in svchost.exe.
- It executes the following command:
- "%System%\schtasks.exe" /create /ru SYSTEM /tn TMUpdate /tr "powershell.exe -encodedCommand {Base64 encoded string" /sc ONSTART /f
- The scheduled task connects to the following URL to download and execute arbitrary malicious code:
- http://{BLOCKED}.{BLOCKED}.227.242/qa.ph
- Terminates running svchost.exe process without service information.
It uses the system's central processing unit (CPU) and/or graphical processing unit (GPU) resources to mine cryptocurrency. This behavior makes the system run abnormally slow.
SOLUTION
Step 1
Before doing any scans, Windows XP, Windows Vista, and Windows 7 users must disable System Restore to allow full scanning of their computers.
Step 2
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 3
Restart in Safe Mode
Step 4
Deleting Scheduled Tasks
For Windows 2000, Windows XP, and Windows Server 2003:
- Open the Windows Scheduled Tasks. Click Start>Programs>Accessories>
System Tools>Scheduled Tasks. - Locate each task that has the following value in the Schedule column:
- TMUpdate
- Right-click on the said file(s) with the aforementioned value.
- Click on Properties. In the Run field, check for the following string:
Cmd /c /rd /s /q C: - If the said string is found, delete the task.
For Windows Vista, Windows 7, Windows Server 2008, Windows 8, Windows 8.1, and Windows Server 2012:
- Open the Windows Task Scheduler. To do this:
• On Windows Vista, Windows 7, and Windows Server 2008, click Start, type taskschd.msc in the Search input field, then press Enter.
• On Windows 8, Windows 8.1, and Windows Server 2012, right-click on the lower left corner of the screen, click Run, type taskschd.msc, then press Enter. - In the left panel, click Task Scheduler Library.
- In the upper-middle panel, locate each task that has the value in the Triggers column:
- TMUpdate
- In the lower-middle panel, click the Actions tab. In the Details column, check for the following string:
Cmd /c /rd /s /q C: - If the said string is found, delete the task..
Step 5
Search and delete this file
- %Application Data%\appinit.bat
Step 6
Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_SHELLINJCT.A. 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 7
Scan your computer with your Trend Micro product to delete files detected as TROJ_SHELLINJCT.A. 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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