Analysis by: Rheniel Rhay Ramos
ALIASES:

Trojan:Win32/Jaku.A!dha (Microsoft); Trojan.Jakubot (Symantec)

 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

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 connects to certain websites to send and receive information. However, as of this writing, the said sites are inaccessible. It gathers information and reports it to its servers.

  TECHNICAL DETAILS

File Size: 406,016 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 07 Nov 2015
Payload: Connects to URLs/IPs

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:

  • %User Temp%\{Random}.tmp -> deleted afterwards
  • %User Temp%\adobe.exe -> deleted afterwards
  • %User Temp%\checkrun.bat -> deleted afterwards
  • %User Temp%\makejob.exe -> deleted afterwards
  • %Application Data%\temp\adobe.exe -> moved and renamed as Services.exe

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.. %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 drops and executes the following files:

  • %User Temp%\sound1.exe -> Normal File (MPEG4 Modifier)
  • %User Temp%\sound2.exe -> also detected as TROJ_JAKU.A (deleted afterwards)
  • %User Temp%\2run.bat -> used to execute sound1.exe and sound2.exe (deletes itself) <- detected as BAT_JAKU.A
  • %Application Data%\temp\checkrun.bat -> creates directory, move adobe.exe, and execute makejob.exe (deletes itself) <- detected as BAT_JAKU.A
  • %Application Data%\temp\makejob.exe -> used to create scheduled task
  • %Application Data%\temp\end.bat -> used to delete sound 2.exe (deletes itself)
  • %Application Data%\Adobe\Updates\Services.exe -> also detected as TROJ_JAKU.A

(Note: %User Temp% is the user's temporary folder, where it usually is C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, Windows Server 2003, and Windows XP (32- and 64-bit); C:\Users\{user name}\AppData\Local\Temp 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.. %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 processes:

  • cmd.exe /u /c systeminfo
  • cmd.exe /u /c net use
  • cmd.exe /u /c net user
  • cmd.exe /u /c tasklist /svc
  • cmd.exe /u /c netstat -ano
  • cmd.exe /u /c dir "%USERPROFILE%\Recent"
  • cmd.exe /u /c dir "%APPDATA%\Microsoft\Windows\Recent"
  • cmd.exe /u /c dir /s/b "%USERPROFILE%\Favorites"

It creates the following folders:

  • %Application Data%\Adobe\Updates

(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.)

Other System Modifications

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

HKEY_CURRENT_USER\CLSID
= "{CLSID}"

HKEY_CURRENT_USER\CLSID
System = "{Number}"

HKEY_CURRENT_USER\CLSID
WindowsUpdate = "0"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\RunOnce
ucheck = "C:\Users\dyituser_732\AppData\Roaming\temp\makejob.exe" -tn "Update checker" -ds "Adobe Update Validation Checker" -tr "C:\Users\dyituser_732\AppData\Roaming\Adobe\Updates\Services.exe" -sc "MINUTE" -mo "30"

Other Details

This Trojan connects to the following website to send and receive information:

  • http://boardchk.{BLOCKED}led.net/index.php
  • http://minicooper.{BLOCKED}s.com/index.php
  • http://minicooper.{BLOCKED}killer.com/index.php
  • http://cutemini.{BLOCKED}de.com/index.php
  • http://winchk.{BLOCKED}ex.com/index.php
  • http://browny.{BLOCKED}s.net/index.php
  • http://sweetbrowny.{BLOCKED}o.com/index.php
  • http://cometome.{BLOCKED}ap.com/index.php
  • http://torrent.{BLOCKED}ks.com/index.php
  • http://torrentfiles.{BLOCKED}s.net/index.php
  • http://movieadd.{BLOCKED}o.com/index.php
  • http://torrent3.{BLOCKED}ex.com/index.php

It does the following:

  • It opens a normal file and proceeds with its routines only after the window has been closed:

However, as of this writing, the said sites are inaccessible.

It gathers the following information and reports it to its servers:

  • System Information
  • Mapped Drives and Deveices
  • User Accounts
  • Active Processes
  • TCP/IP Network Connections
  • List of files and subfolders in the following directories:
    • %User Profile%\Recent
    • %Application Data%\Microsoft\Windows\Recent
    • %User Profile%\Favorites

(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 scheduled tasks:

  • Task Name: Update checker
    Schedule: Every 30 Minutes
    Task to be Run: %Application Data%\Adobe\Updates\Services.exe

(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.)

  SOLUTION

Minimum Scan Engine: 9.850
FIRST VSAPI PATTERN FILE: 14.220.06
FIRST VSAPI PATTERN DATE: 29 Apr 2018
VSAPI OPR PATTERN File: 14.221.00
VSAPI OPR PATTERN Date: 30 Apr 2018

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

Identify and terminate files detected as TROJ_JAKU.A

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 4

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.

 
  • In HKEY_CURRENT_USER
    • CLSID

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\RunOnce
    • ucheck = "C:\Users\dyituser_732\AppData\Roaming\temp\makejob.exe"  -tn "Update checker" -ds "Adobe Update Validation Checker" -tr "C:\Users\dyituser_732\AppData\Roaming\Adobe\Updates\Services.exe" -sc "MINUTE" -mo "30"

Step 6

Deleting Scheduled Tasks

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

  • Task Name: Update checker - %Application Data%\Adobe\Updates\Services.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 7

Search and delete these folders

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %Application Data%\Adobe\Updates

Step 8

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.
  • %User Temp%\sound1.exe
  • %User Temp%\sound2.exe
  • %User Temp%\2run.bat
  • %User Temp%\{Random}.tmp
  • %User Temp%\adobe.exe
  • %User Temp%\checkrun.bat
  • %User Temp%\makejob.exe
  • %Application Data%\temp\checkrun.bat
  • %Application Data%\temp\makejob.exe
  • %Application Data%\temp\end.bat
  • %Application Data%\temp\adobe.exe

Step 9

Scan your computer with your Trend Micro product to delete files detected as TROJ_JAKU.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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