JAVA_EXPLOYT.YYS

June 06, 2014
 Analysis by: Jaime Benigno Reyes
 ALIASES:

Exploit:Java/CVE-2012-0507 (Microsoft), HEUR:Exploit.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:

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet

This Trojan may be hosted on a website and run when a user accesses the said website.

  TECHNICAL DETAILS

File Size:

Varies

File Type:

Java Class

Initial Samples Received Date:

27 May 2014

Payload:

Downloads files

Arrival Details

This Trojan may be hosted on a website and run when a user accesses the said website.

Download Routine

This Trojan takes advantage of the following software vulnerabilities to download possibly malicious files:

It saves the files it downloads using the following names:

  • %User Temp%\{random file name 1}.tmp
  • %User Temp%\{random file name 2}.tmp

(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 downloads a possibly malicious file from a certain URL. The URL where this malware downloads the said file depends on the following parameter(s) passed on to it by its components:

  • data
  • jar
  • lhost
  • lport

NOTES:

This malware combines the two downloaded files into one file named %User Temp%\{random file name 3}.cpl. It does this by creating a batch file named %User Temp%\{random file name 3}.bat that contains the following command:

copy "%User Temp%\{random file name 1}.tmp" /b + "%User Temp%\{random file name 2}.tmp" %User Temp%\{random file name 4}.cpl /y"

This malware uses Windows Task Scheduler to create scheduled tasks for {random file name 3}.bat and {random file name 4}.cpl. In the said scheduled tasks, the file {random file name 3}.bat runs once 10 minutes after the malware JAVA_EXPLOYT.YYS is executed, while the file {random file name 4}.cpl runs once 11 minutes after the malware JAVA_EXPLOYT.YYS is executed. As a result, malicious routines of the downloaded files are exhibited on the affected system.

  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

10.822.04

FIRST VSAPI PATTERN DATE:

27 May 2014

VSAPI OPR PATTERN File:

10.823.00

VSAPI OPR PATTERN Date:

28 May 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

Close all opened browser windows

Step 3

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%\{random file name 1}.tmp
  • %User Temp%\{random file name 2}.tmp
  • %User Temp%\{random file name 3}.cpl
  • %User Temp%\{random file name 4}.bat

Step 4

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

Step 5

Download and apply this security patch Refrain from using these products until the appropriate patches have been installed. Trend Micro advises users to download critical patches upon release by vendors.


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