TROJ_JAKU.B

 Analysis by: Rheniel Rhay Ramos

 ALIASES:

Trojan:Win32/Jaku.A (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:

119,800 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

22 Dec 2013

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 copies of itself into the affected system:

  • %User Profile%\Temp\~

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

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:

  • %User Profile%\Temp
  • %User Profile%\Startup

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

Autostart Technique

This Trojan drops the following file(s) in the Windows User Startup folder to enable its automatic execution at every system startup:

  • %User Profile%\Startup\wuauclt.exe

(Note: %User Profile% is the current user's profile folder, which is usually C:\Documents and Settings\{user name} on Windows 2000, XP, and Server 2003, or C:\Users\{user name} on Windows Vista and 7.)

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\Explorer\
User Shell Folders
Startup = %User Profile%\Startup"

Other Details

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

  • http://winupdates.{BLOCKED}o.tm/index.php
  • http://updates.{BLOCKED}d.info/index.php
  • http://torrent.{BLOCKED}s.net/index.php
  • http://decrypt.{BLOCKED}d.info/index.php
  • http://decrypt.{BLOCKED}o.tm/index.php
  • http://torrent.{BLOCKED}log.net/index.php
  • http://decrypt.{BLOCKED}s.com/index.php
  • http://file2.{BLOCKED}led.net/index.php
  • http://blog3.{BLOCKED}log.net/index.php
  • http://torent.{BLOCKED}d.info/index.php
  • http://dns53.{BLOCKED}elist.com/index.php
  • http://www.{BLOCKED}ates.comxa.com/index.php

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.)

  SOLUTION

Minimum Scan Engine:

9.850

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.B

[ 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\Explorer\User Shell Folders
    • Startup = "%User Profile%\Startup"

Step 6

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.  
  • %User Profile%\Temp
  • %User Profile%\Startup

Step 7

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