Symantec Security Response - W32.Balick.Trojan W32.Balick.Trojan is a Trojan horse that attempts to obtain an ad-click credit for the Trojan's author. It will copy itself to the \System folder as Csss.exe. Type: Trojan Horse Infection Length: 28,672 bytes Systems Affected: Windows 95, Windows 98, Windows NT, Windows 2000, Windows XP, Windows Me Systems Not Affected: Windows 3.x, Macintosh, OS/2, Unix, Linux technical details When it is executed, W32.Balick.Trojan displays this message box: http://securityresponse.symantec.com/avcenter/graphics/w32.balick.trojan.1.gif If you click "I agree," the Trojan: 1. Copies itself as the file %windir%\System\Csss.exe NOTE: %windir% is a variable. The Trojan locates the Windows installation folder (by default this is C:\Windows or C:\Winnt) and copies itself to the \System folder in that location. 2. It adds the value csss %windir%\System\Csss.exe to the registry key HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Run As a result, then next time that you start Windows (and each time after that) the Trojan runs and contacts many Web sites in an attempt to gain ad-clicks for the Trojan's author. If I click "I do not Agree," the Trojan exits. removal instructions NOTE: These instructions are for all current and recent Symantec antivirus products, including the Symantec AntiVirus and Norton AntiVirus product lines. 1. Update the virus definitions 2. Run a full system scan. 3. Delete all files that are detected as W32.Balick.Trojan. 4. Delete the value csss %windir%\System\Csss.exe from the registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run To delete the value from the registry: CAUTION: Symantec strongly recommends that you back up the registry before you make any changes to it. Incorrect changes to the registry can result in permanent data loss or corrupted files. Modify only the keys that are specified. Read the document How to make a backup of the Windows registry for instructions. 1. Click Start, and click Run. The Run dialog box appears. 2. Type regedit and then click OK. The Registry Editor opens. 3. Navigate to the key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run 4. In the right pane, delete the value csss %windir%\System\Csss.exe 5. Exit the Registry Editor.