Trojan.Win32.SMOKELOADER.BF
HEUR:Trojan.MSIL.Taskun.gen (Kaspersky); Trojan.Inject (Ikarus)
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 injects its dropped file/component to specific processes.
It does not have any propagation routine.
It does not have any backdoor routine.
It does not have any proxy server routine.
It terminates itself if it detects it is being run in a virtual environment. It deletes itself after execution.
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 copies of itself into the affected system:
- %Application Data%\xFFgPbPjc.exe
- %Application Data%\{random name generated from system information} -> copy of embedded file in the original malware sample
(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 drops the following files:
- %Application Data%\{random name generated from system information} -> downloaded component
- %User Temp%\tmp{Random characters}.tmp -> XML file of scheduled task
- %User Temp%\44DA.tmp -> copy of ntdll.dll
(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).. %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:
- hEEGiYfYVPKLqPCGdBwOGnewhnI
- {Random hash from system information}
It injects its dropped file/component to the following processes:
- explorer.exe
It injects codes into the following process(es):
- explorer.exe
It terminates itself if it finds the following processes in the affected system's memory:
- qemu-ga.exe
- qga.exe
- windanr.exe
- vboxservice.exe
- vboxtray.exe
- vmtoolsd.exe
- prl_tools.exe
Other System Modifications
This Trojan deletes the following files:
- %Application Data%\{dropped copy with random name}:Zone.Identifier
(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).)
Propagation
This Trojan does not have any propagation routine.
Backdoor Routine
This Trojan does not have any backdoor routine.
Rootkit Capabilities
This Trojan does not have rootkit capabilities.
Process Termination
This Trojan terminates the following processes if found running in the affected system's memory:
- OllyDbg.exe
- ProcessHacker.exe
- procmon.exe
- procexp.exe
- wireshark.exe
- autoruns.exe
- idaq.exe
- tcpview.exe
Proxy Server Routine
This Trojan does not have any proxy server routine.
Information Theft
This Trojan gathers the following data:
- Computer Name
- System Volume Information
- Internet Explorer version
- User Agent String
- User Name
Stolen Information
This Trojan sends the gathered information via HTTP POST to the following URL:
- http://{BLOCKED}sky.net/
Other Details
This Trojan terminates itself if it detects it is being run in a virtual environment.
It deletes itself after execution.
It checks if the following virtual machine- or sandbox-related registry keys are present in the affected system:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Enum\IDE
HKEY_LOCAL_MACHINE\System\CurrentControlSet\
Enum\SCSI
It checks if the following virtual machine or sandbox related folder(s) or file(s) is present in the affected system:
- Checks filenames in the %System% and %System%\drivers directories for filenames with the following substrings and terminates itself if found:
- vmci.s
- vmusbm
- vmmous
- vm3dmp
- vmrawd
- vmmemcc
- vboxgu
- vboxsf
- vboxmo
- vboxvi
- vboxdi
- vioser
(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)
It does not proceed to its malicious routine if it detects that it is being debugged.
It adds the following scheduled tasks:
- Task Name: NvNgxUpdateCheckDaily_{{random values}-{random values}-{random values}-{random values}-{random values}}
- Trigger 1: At User Logon
- Trigger 2: Every 10 minutes starting from 11/30/1999 12:00 AM
- Action: Start program "%Application Data%\{dropped copy with random name}:
- Task Name: Updates\xFFgPbPjc
- Trigger and Actions: Specified in XML file "%User Temp%\tmp{Random characters}.tmp"
(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).. %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).)
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.XXPE50FFF036
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
Deleting Scheduled Tasks
The following {Task Name} - {Task to be run} listed should be used in the steps identified below:
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 6
Search and delete this file
- %Application Data%\xFFgPbPjc.exe
- %User Temp%\tmp{Random characters}.tmp
- %User Temp%\44DA.tmp
- %Application Data%\{random name generated from system information}
- %Application Data%\{random name generated from system information}
Step 7
Restart in normal mode and scan your computer with your Trend Micro product for files detected as Trojan.Win32.SMOKELOADER.BF. 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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