Trojan.Win32.Costaro

Class Trojan
Platform Win32
Description

Technical Details

This Trojan is a Windows PE EXE file. It is 33 792 bytes in size.

Installation

When launched, the Trojan copies its executable file to the Windows root directory:

%WinDir%Winrep.exe

In order to ensure that the Trojan is launched automatically each time Windows is restarted, it adds a link to its executable file to the system registry:

[HKCUSoftwareMicrosoftWindows NTCurrentVersionWindows]
"Run" = "%WinDir%Winrep.exe"

[HKCUSoftwareMicrosoftWindows NTCurrentVersionWindows]
"load" = "%WinDir%Winrep.exe"

The Trojan also creates the following system registry key parameter:

[HKLMSOFTWAREMicrosoftWindows NTCurrentVersionCompatibility]
"COSTARO" = "10.05.2007"

The Trojan also creates the following empty file.

%WinDir%winrep.log

Payload

The Trojan will periodically cause the following message to be displayed:

Removal instructions

If your computer does not have an up-to-date antivirus, or does not have an antivirus solution at all, follow the instructions below to delete the malicious program:

  1. Use Task Manager to terminate the Trojan process
  2. Delete the original Trojan file (the location will depend on how the program originally penetrated the victim machine).
  3. Delete the following parameters from the system registry (see What is a system registry and how do I use it for details on how to edit the registry).
    [HKCUSoftwareMicrosoftWindows NTCurrentVersionWindows]
    "Run" = "%WinDir%Winrep.exe"
    
    [HKCUSoftwareMicrosoftWindows NTCurrentVersionWindows]
    "load" = "%WinDir%Winrep.exe"
    
    [HKLMSOFTWAREMicrosoftWindows NTCurrentVersionCompatibility]
    "COSTARO" = "10.05.2007"
  4. Delete the following files:
    %WinDir%Winrep.exe
    %WinDir%winrep.log
  5. Update your antivirus databases and perform a full scan of the computer (download a trial version of Kaspersky Anti-Virus).