JAVA_DLOAD.ZUNY

February 13, 2014
 Analysis by: Mark Joseph Manahan
 ALIASES:

HEUR:Trojan.Java.Generic (Kaspersky)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • 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 when a user accesses certain websites where it is hosted.

As of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size:

18,275 bytes

File Type:

JAR

Memory Resident:

Yes

Initial Samples Received Date:

11 Feb 2014

Payload:

Connects to URLs/IPs, Downloads files

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.

It executes when a user accesses certain websites where it is hosted.

Installation

This Trojan drops the following files:

  • %User Desktop%\google chrome.lnk

It drops and executes the following files:

  • %User Temp%\oxml.vbs
  • %User Temp%\windows.vbs
  • %User Temp%\realhowto.vbs

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

It leaves the following text files:

  • %All Users Profile%\Google\Chrome\Systemcertificates\logerro.log

(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.)

Download Routine

This Trojan connects to the following URL(s) to download its component file(s):

  • http://{BLOCKED}utoraincorporadoraborges.zip.net/fotos/icon.png
  • http://{BLOCKED}utoraincorporadoraborges.zip.net/fotos/manifest.jpg
  • http://{BLOCKED}utoraincorporadoraborges.zip.net/fotos/manifest.png
  • http://{BLOCKED}utoraincorporadoraborges.zip.net/fotos/installupdate.png
  • http://{BLOCKED}iariaantonioso.hospedagemdesites.ws/engineering/avisoinstall.php?inf={number}

It saves the files it downloads using the following names:

  • %All Users Profile%\Google\Chrome\Systemcertificates\icon.png
  • %All Users Profile%\Google\Chrome\Systemcertificates\manifest.js
  • %All Users Profile%\Google\Chrome\Systemcertificates\manifest.json
  • %All Users Profile%\Sun\Java\Java Update\checkupdatejava.jar

(Note: %All Users Profile% is the All Users or Common profile folder, which is C:\Documents and Settings\All Users in Windows 2000, XP, and Server 2003, and C:\ProgramData in Windows Vista and 7.)

As of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

10.602.01

FIRST VSAPI PATTERN DATE:

11 Feb 2014

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

Restart in Safe Mode

[ Learn More ]

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.  
  • %All Users Profile%\Google\Chrome\Systemcertificates\icon.png
  • %All Users Profile%\Google\Chrome\Systemcertificates\manifest.js
  • %All Users Profile%\Google\Chrome\Systemcertificates\manifest.json
  • %All Users Profile%\Sun\Java\Java Update\checkupdatejava.jar
  • %User Temp%\oxml.vbs
  • %User Temp%\windows.vbs
  • %User Temp%\realhowto.vbs

Step 4

Restart in normal mode and scan your computer with your Trend Micro product for files detected as JAVA_DLOAD.ZUNY. 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.


Did this description help? Tell us how we did.