Trojan.JS.QAKBOT.YQLGA
TrojanDownloader:JS/Nemucod.G!MSR(MICROSOFT);
Windows
Threat Type: Trojan
Destructiveness: No
Encrypted:
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.
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:
- %ProgramData%\{random string1}.bat → combines the two downloaded files to create %ProgramData%\{random string1}.exe
(Note: %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit), or C:\Documents and Settings\All Users on Windows Server 2003(32-bit), 2000(32-bit) and XP.)
It adds the following processes:
- "%System%\schtasks.exe" /Create /SC ONCE /TN {random string1} /TR "cmd /c \"start /min %ProgramData%\{random string1}.bat\"" /ST {time executed + 5 minutes}
- If download fails:
- %System%\schtasks.exe /Change /Disable /TN {random string1}
- %System%\schtasks.exe /Delete /TN {random string1}
(Note: %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit), or C:\Documents and Settings\All Users on Windows Server 2003(32-bit), 2000(32-bit) and XP.)
Download Routine
This Trojan connects to the following website(s) to download and execute a malicious file:
- http://backup.justth{BLOCKED}.com/datacollectionservice.php3
- http://a{BLOCKED}.c{BLOCKED}.com.pa/datacollectionservice.php3
- http://chs.zarifb{BLOCKED}.com/datacollectionservice.php3
It saves the files it downloads using the following names:
- %ProgramData%\{random string1} → contains first 1000 bytes of downloaded file
- %ProgramData%\{random string2} → contains the rest of the downloaded file
- %ProgramData%\{random string1}.exe → detected as Backdoor.Win32.QAKBOT.SMF1
(Note: %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit), or C:\Documents and Settings\All Users on Windows Server 2003(32-bit), 2000(32-bit) and XP.)
Other Details
This Trojan adds the following scheduled tasks:
- Task Name: {random string1}
- Task Run: "cmd /c "start /min %ProgramData%\{random string1}.bat""
- Task Schedule: {time executed + 5 minutes}
(Note: %ProgramData% is a version of the Program Files folder where any user on a multi-user computer can make changes to programs. This contains application data for all users. This is usually C:\ProgramData on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit), or C:\Documents and Settings\All Users on Windows Server 2003(32-bit), 2000(32-bit) and XP.)
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:
- Downloader.JS.TRX.XXJSE9EFF014
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
Search and delete this file
- %ProgramData%\{random string1}
- %ProgramData%\{random string1}.bat
- %ProgramData%\{random string1}.exe
- %ProgramData%\{random string2}
Step 6
Deleting Scheduled Tasks
The following {Task Name} - {Task to be run} listed should be used in the steps identified below:
- {random string1} - "cmd /c "start /min %ProgramData%\{random string1}.bat""
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 Name} values listed above in the Name column.
- Right-click on the said file(s) with the aforementioned value.
- Click on Properties. In the Run field, check for the listed {Task to be run}.
- If the strings match the list above, 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 Name} values listed above in the Name column.
- In the lower-middle panel, click the Actions tab. In the Details column, check for the {Task to be run} string.
- If the said string is found, delete the task.
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Trojan.JS.QAKBOT.YQLGA. 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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