Classification

Category: Malware

Type: -

Aliases: Ouch, Java/Ouch.A

Summary


Ouch.A is a Java applet based trojan that downloads and installs WinShow (winshow.dll) spyware on the system.

Ouch activates when user views a web page or HTML email that contains reference to the trojan file.

Ouch does not replicate and does not infect the host system, the only operations it does is to download and install WinShow spyware component.

Removal


Automatic action

Based on the settings of your F-Secure security product, it will either automatically delete, quarantine or rename the detected program or file, or ask you for a desired action.

Knowledge Base

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About the product

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Submit a sample

Submit a file or URL for further analysis.

Technical Details


When a JAR file containing the trojan is executed it uses Microsoft Internet Explorer VerifierBug vulnerability to get full privileges by escaping the Java security, and execute its code. Then the trojan downloads the winshow.dll into windows directory (default C:\Windows) and registers it with regsvr32.

To remove Ouch.A from your system apply the fix to the Java VM vulnerability and clear temporary Internet files cache

Further information about the vulnerability in the Microsoft Java VM, including a fix, is available at:

https://www.microsoft.com/technet/security/bulletin/ms03-011.asp