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JAVA_EXPLOIT.RG
Aliases: Exploit.Java.Agent.ic (Kaspersky), Java/Exploit.Agent.NEF trojan (Eset)
Malware type: Trojan
Destructive: No
Platform: Windows 2000, Windows XP, Windows Server 2003
Encrypted: Yes
In the wild: Yes

Overview


Infection Channel: Downloaded from the Internet, Dropped by other malware

This malware is involved in the Blackhole Exploit Kit (BHEK) attacks in January 2013. It takes advantage of a zero-day vulnerability (CVE-2013-0422) in Java in order to drop ransomware. Victims may find themselves being extorted for money.

To get a one-glance comprehensive view of the behavior of this Trojan, refer to the Threat Diagram shown below.

For the related story, you may read the blog post Microsoft, Oracle Release Security Fixes for Zero-Day Exploits

This Trojan may be downloaded by other malware/grayware from remote sites.

It takes advantage of unknown vulnerabilities in certain software to download malicious files.

Technical Details


File size: Varies
File type: JAR
Initial samples received date: 10 Jan 2013
Payload: Downloads files

Arrival Details

This Trojan may be downloaded by the following malware/grayware from remote sites:

  • HTML_EXPLOIT.RG

It may be downloaded from the following remote site(s):

  • http://{BLOCKED}enhaupdad.bounceme.net/read/UTTER-OFFEND.JAR

Download Routine

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

  • Java Runtime Environment (1.7 Update 9 & Update 10)

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

  • Oracle Java 7 Security Manager Bypass Vulnerability (CVE-2013-0422)

It saves the files it downloads using the following names:

  • %User Profile%\awt43abr.exe
  • %User Profile%\berstrestvers.exe
  • %User Profile%\bawt34tv.exe
  • %User Profile%\tab4vrtve.exe
  • %User Profile%\wgsdgsdgdsgsd.exe
  • %User Profile%\ab43yctewatv.exe
  • %User Profile%\a43vtzgbdgv.exe
  • %User Profile%\atv4tvq34.exe
  • %User Profile%\bg34dfbewgba4.exe
  • %User Profile%\av4a43by4ayb.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.)

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:

  • val
  • prime

Other Details

This Trojan executes the downloaded file using the following commands:

  • regsvr32 -s %User Profile%\{file name}.exe
  • %User Profile%\{file name}.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.)

NOTES:

This malware exploits the vulnerability found in Java Runtime Environment 1.7 Update 9 and Update 10.

Solution


Minimum scan engine: 9.300
First VSAPI Pattern File: 9.648.06
First VSAPI Pattern Release Date: 10 Jan 2013
VSAPI OPR Pattern Version: 9.649.00
VSAPI OPR Pattern Release Date: 11 Jan 2013

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

Remove the malware/grayware file that dropped/downloaded JAVA_EXPLOIT.RG

Step 3

Restart in Safe Mode

[ Learn more ]

Step 4

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 Profile%\awt43abr.exe
  • %User Profile%\berstrestvers.exe
  • %User Profile%\bawt34tv.exe
  • %User Profile%\tab4vrtve.exe
  • %User Profile%\wgsdgsdgdsgsd.exe
  • %User Profile%\ab43yctewatv.exe
  • %User Profile%\a43vtzgbdgv.exe
  • %User Profile%\atv4tvq34.exe
  • %User Profile%\bg34dfbewgba4.exe
  • %User Profile%\av4a43by4ayb.exe

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as JAVA_EXPLOIT.RG. 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 6

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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Analysis By: Mark Joseph Manahan

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