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JAVA_BANLOAD.YWNRB

October 12, 2016
 Analysis by: Cris Nowell Pantanilla
 Modified by: Marvelous Pelin
 ALIASES:

Trojan:Java/Jarvis.A!gfc(Microsoft);Trojan.JAVA.Downloader.HU(BitDefender)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 REPORTED INFECTION:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: Yes

  • 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 executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

It connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Size:

26524 bytes

File Type:

JAR, Java

Memory Resident:

No

Initial Samples Received Date:

07 Oct 2016

Payload:

Downloads files, Executes files, 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:

  • %Application Data%\Sun\Java\Deployment\{random string}\{random string}.mp3 (decompressed copy of pp64.pdf or pp32.pdf)
  • %Application Data%\Sun\Java\Deployment\{random string}\{random string}.xml (decompressed copy of ss64.pdf or ss32.pdf)
  • %Application Data%\Sun\Java\Deployment\{random string}\{random string}.wmv (decompressed copy of jjgf.pdf)
  • %Application Data%\Sun\Java\Deployment\{random string}\{random string}.bat - executes ".xml" file
  • %User StartUp%\{random}.LNK - point to real{random numbers}.vbs
  • %User Temp%\real{random numbers}.vbs - execute downloaded files
  • %User Temp%\tmp{random numbers}.vbs - get drive serial number

(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.. %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.)

It creates the following folders:

  • %Application Data%\Sun\Java\Deployment\{random string}

(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.)

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

  • http://{BLOCKED}ariamisteruvacrow.com.br/pdf/pp64.pdf (64-bit)
  • http://{BLOCKED}ariamisteruvacrow.com.br/pdf/ss64.pdf (64-bit)
  • http://{BLOCKED}ariamisteruvacrow.com.br/pdf/pp32.pdf (32-bit)
  • http://{BLOCKED}ariamisteruvacrow.com.br/pdf/ss32.pdf (32-bit)
  • http://{BLOCKED}ariamisteruvacrow.com.br/pdf/jjgf.pdf

It saves the files it downloads using the following names:

  • %Application Data%\{random string}\pp64.pdf (64-bit)
  • %Application Data%\{random string}\ss64.pdf (64-bit)
  • %Application Data%\{random string}\pp32.pdf (32-bit)
  • %Application Data%\{random string}\ss32.pdf (32-bit)
  • %Application Data%\{random string}\jjgf.pdf

(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 then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

Information Theft

This Trojan gathers the following data:

  • Hostname
  • Drive Serial Number
  • OS Name
  • GbPlugin Path

Other Details

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

  • http://{BLOCKED}ariamisteruvacrow.com.br/pdf/B5CB.php?9FD136={Hostname}&8CFC02={OS Name}&6090F9={GBplugin Path}&295BA5={Drive Serial Number}

It does the following:

  • It checks if the affected machine is in the following countries:
    • Brasil
    • Portugal
  • It checks if the following file exist:
    • %Application Data%\Sun\Java\Deployment\Sun.jar
  • It executes the following command to restart the affected machine:
    • shutdown -r -t 30 -c Atualizando...

(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:

9.800

FIRST VSAPI PATTERN FILE:

12.822.08

FIRST VSAPI PATTERN DATE:

07 Oct 2016

VSAPI OPR PATTERN File:

12.823.00

VSAPI OPR PATTERN Date:

08 Oct 2016

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

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%\Sun\Java\Deployment\{random string}
%Application Data%\{random string}

Step 3

Search and delete this file

[ 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.
%Application Data%\Sun\Java\Deployment\{random string}\{random string}.mp3
%Application Data%\Sun\Java\Deployment\{random string}\{random string}.xml
%Application Data%\Sun\Java\Deployment\{random string}\{random string}.wmv
%Application Data%\Sun\Java\Deployment\{random string}\{random string}.bat
%User StartUp%\{random}.LNK
%User Temp%\tmp{random numbers}.vbs
%User Temp%\real{random numbers}.vbs
%Application Data%\{random string}\pp64.pdf
%Application Data%\{random string}\ss64.pdf
%Application Data%\{random string}\pp32.pdf
%Application Data%\{random string}\ss32.pdf
%Application Data%\{random string}\jjgf.pdf

Step 4

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