Trojan-Downloader.Java.OpenConnection.cf

Technical Details
Payload
Removal instructions

Technical Details

This Trojan downloads files from the Internet and launches them without the user's knowledge. It is a Java class file. It is 2241 bytes in size.

Payload

The malware is a component of a Trojan downloader and includes a class file named "a", which downloads a file from the Internet, from a link sent to it, and launches the downloaded file for execution. The file is saved in the current user's temporary files directory as

%Temp%\<rnd>.exe

where <rnd> is a random fractional decimal number between 0 and 1. Before downloading, it checks the name of the OS installed on the infected system. If the OS is not Windows, the download does not take place.

As well as the above-mentioned class file, the Trojan includes class files named "b" and "KAVS", which contain a functionality to decrypt a link sent to it, and to exploit the vulnerability CVE-2010-0840.

The Trojan constitutes a Java applet. It is launched from an infected HTML page, using an "<APPLET>" tag, one of the parameters of which is an encrypted link to a downloadable file.

Removal instructions

If your computer does not have an antivirus, and is infected by this malicious program, follow the instructions below to delete it:

1. Update Sun Java JRE and JDK to the latest versions.
2. Delete the following file:

   %Temp%\<rnd>.exe

3. Empty the Temporary Internet Files directory, which may contain infected files (see How to delete infected files from Temporary Internet Files folder?).

   %Temporary Internet Files%

4. Perform a full scan of the computer using Kaspersky Anti-Virus with up-to-date antivirus databases (download a trial version).