Trojan-Downloader.Win32.IMCdown

Technical Details

This Trojan downloads files via the Internet without the user’s knowledge or consent.

It is a Windows PE EXE file. It is written in Borland C++. It has the following components:

• CLIENT.EXE — 57 344 bytes
• SERVER.EXE — 65 024 bytes
• X.EXE — 4 096 bytes

Payload

The Trojan program (X.EXE) attempts to establish a TCP connection to 116.116.199.216:62324 (216.216.216.216:55512). If a connection is not established within 30 seconds, the Trojan will terminate its process. If a connection is established, the Trojan will create a file called “anyfile.exe” in the current directory, write downloaded data to this file, and then launch the file for execution. The Trojan will then cease running.

The Trojan uses a ZFTP server on port 12345 to download data. When the client component (CLIENT.EXE) is launched, it sends a broadband request to check port 12345. If the address of the computer where the server component (SERVER.EXE) is installed is given as a command line parameter, then a connection will be established to this machine on the designated port. Files will then be downloaded from the server.

Removal instructions

1. Use Task Manager to terminate the Trojan process.
2. Delete the original Trojan files (the location will depend on how the program originally penetrated the victim machine).
3. Update your antivirus databases and perform a full scan of the computer (download a trial version of Kaspersky Anti-Virus).