Analysis by: Carl Maverick Pascual
 Modified by: Maureen Reyes

ALIASES:

Trojan.Win32.Fsysna.ezky (Kaspersky) ; Trojan:Win32/Tiggre!rfn (Microsoft)

 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: 201,776 bytes
File Type: EXE
Initial Samples Received Date: 26 Jan 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 drops and executes the following files:

  • %Temp%\ttt.exe -> modified copy of itself. Detected as Trojan.Win32.INFOSTEAL.ADS
  • %System%\wmiex.exe -> modified copy of itself. Detected as Trojan.Win32.INFOSTEAL.ADS
  • %System%\drivers\taskmgr.exe -> detected as Coinminer.Win32.MALXMR.ADS

It drops the following copies of itself into the affected system:

  • %System%\drivers\svchost.exe
  • %System%\svhost.exe

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

It adds the following processes:

  • netsh firewall add portopening tcp 65532 UDP
  • netsh firewall add portopening tcp 65531 UDP2
  • netsh firewall add portopening tcp 65533 ShareService
  • netsh interface portproxy add v4tov4 listenport=65532 connectaddress=1.1.1.1 connectport=53
  • netsh interface portproxy add v4tov4 listenport=65531 connectaddress=1.1.1.1 connectport=53

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • AHDPQOE987aaapb7
  • it is holy shit

Autostart Technique

This Trojan adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Ddriver = %System%\drivers\svchost.exe

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
WebServers = %System%\wmiex.exe

It adds and runs the following services:

  • Ddriver:
    • Description: Provides abilitiy to share TCP ports over the net.tcp protocol {Date of Installation}
    • Path: %System%\drivers\svchost.exe
  • WebServers:
    • Description: forwards it to Provide HTTP Servers.
    • Path: %System%\wmiex.exe

(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 keys:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\Ddriver

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\WebServers

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\PortProxy\v4tov4

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

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\WebServers
ImagePath = %System%\wmiex.exe

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\WebServers
DisplayName = WebServers

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\Ddriver
DisplayName = Ddriver

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\
services\Ddriver
ImagePath = %System%\drivers\svchost.exe

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

Download Routine

This Trojan accesses the following websites to download files:

  • http://ii.{BLOCKED}.net/u.png?{Stolen Info}
  • http://p.{BLOCKED}.com/im.png?{Stolen Info}
  • http://i.{BLOCKED}.net/i.png?{Stolen Info}
  • http://o.{BLOCKED}.com/i.png?{Stolen Info}
  • http://{BLOCKED}.{BLOCKED}.107.97/h.bat?{Stolen Info}
  • http://{BLOCKED}.{BLOCKED}.107.97/xmrig-32_1.mlz?{Stolen Info}
  • http://dl.{BLOCKED}.net/ins2.exez?{Stolen Info}

It saves the files it downloads using the following names:

  • %Temp%\h.bat -> cointains flushdns command
  • %Temp%\svchost.exe -> Trojan.WIn32.MIMIKATZ.ADU
  • %Temp%\svchost.mlz -> encrypted file read by taskmgr.exe for its coinminingroutine

Information Theft

This Trojan gathers the following data:

  • Computer Name
  • GUID
  • MAC Address
  • User Name
  • Version
  • Operating System
  • AV Products
  • OS Architecture = 32/64 bit
  • CPU
  • Video Card

Other Details

This Trojan does the following:

  • Terminates all running old version of the malware
  • For 64 bit systems, the value of %System% is equivalent to C:\Windows\SysWOW64
  • Enable port forwarding and enables windows firewall
  • Connects to the following URL to send system information:
    • http://ii.{BLOCKED}.net/u.png?{Stolen Info}
    • http://p.{BLOCKED}.com/im.png?{Stolen Info}
    • http://i.{BLOCKED}.net/i.png?{Stolen Info}
    • http://o.{BLOCKED}.com/i.png?{Stolen Info}
    • http://{BLOCKED}.{BLOCKED}.107.97/h.bat?{Stolen Info}
    • http://{BLOCKED}.{BLOCKED}.107.97/xmrig-32_1.mlz?{Stolen Info}
    • http://dl.{BLOCKED}.net/ins2.exez?{Stolen Info}

It adds the following scheduled tasks:

  • Task Name: Ddrivers
    • Task Action: cmd /c %System%\drivers\svchost.exe
  • Task Name: WebServers
    • Task Action: cmd /c %System%\wmiex.exe

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

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.774.03
FIRST VSAPI PATTERN DATE: 26 Jan 2019
VSAPI OPR PATTERN File: 14.775.00
VSAPI OPR PATTERN Date: 27 Jan 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

Restart in Safe Mode

[ Learn More ]

Step 4

Deleting Scheduled Tasks

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

  • Ddrivers="cmd /c %System%\drivers\svchost.exe"
  • WebServers="cmd /c %System%\wmiex.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

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\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • Ddriver = %System%\drivers\svchost.exe
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run
    • WebServers = %System%\wmiex.exe
  • 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 6

Delete this registry key

[ 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. Before you could do this, you must restart in Safe Mode. For instructions on how to do this, you may refer to this page If the preceding step requires you to restart in safe mode, you may proceed to edit the system registry.

  • HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\Ddriver
  • HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\WebServers

Step 7

Search and delete these files

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.  
  • %Temp%\ttt.exe
  • %System%\wmiex.exe
  • %System%\drivers\taskmgr.exe
  • %System%\drivers\svchost.exe
  • %System%\svhost.exe
  • %Temp%\h.bat
  • %Temp%\svchost.exe
  • %Temp%\svchost.mlz

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Trojan.Win32.INFOSTEAL.ADS. 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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