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TrojanDownloader:Java/OpenStream.AQ


TrojanDownloader:Java/OpenStream.AQ is a Java applet trojan that can be distributed inside a Java .jar package that varies in size. It is a variation of Exploit:Java/CVE-2010-0840.W and exploits the vulnerability described in CVE-2010-0840.



What to do now

To detect and remove this threat and other malicious software that may be installed on your computer, run a full-system scan with an appropriate, up-to-date, security solution. The following Microsoft products detect and remove this threat:

For more information on antivirus software, see http://www.microsoft.com/windows/antivirus-partners/.

Update vulnerable Java applications

This threat exploits a known vulnerability in Java. After removing this threat, make sure that you install the updates available from the vendor. You can read more about this vulnerability in Java, as well as where to download the software update from the following links:

It may be necessary to remove older versions of Java that are still present. Keeping old and unsupported versions of Java on your system presents a serious security risk. To read more about why you should remove older versions of Java, see the following information.

Threat behavior

TrojanDownloader:Java/OpenStream.AQ is a Java applet trojan that can be distributed inside a Java .jar package that varies in size. It is a variation of Exploit:Java/CVE-2010-0840.W and exploits the vulnerability described in CVE-2010-0840.

The .jar package contains the following Java files in a folder named "bpac":

  • a$1.class
  • b.class - the file detected as TrojanDownloader:Java/OpenStream.AQ
  • KAVS.class

Successful exploitation may download and execute a file with a random name in the %TEMP% folder.

Analysis by Patrik Vicol


Symptoms

System changes

The following system changes may indicate the presence of this malware:

  • The presence of the following files:
    • a$1.class
    • b.class - the file detected as TrojanDownloader:Java/OpenStream.AQ
    • KAVS.class

Prevention


Alert level: Severe
First detected by definition: 1.99.835.0
Latest detected by definition: 1.173.2181.0 and higher
First detected on: Mar 08, 2011
This entry was first published on: May 18, 2011
This entry was updated on: May 19, 2011

This threat is also detected as:
  • Java.Trojan.Downloader.OpenConnection.AI (BitDefender)
  • Exploit-ByteVerify (McAfee)
  • Mal/JavaMoC-A (Sophos)