Troj/Orse-B

Please follow the instructions for removing Trojans.

Windows NT/2000/XP/2003

In Windows NT/2000/XP/2003 you will also need to edit the following registry entry for each user who ran the virus. The removal of this entry is optional in Windows 95/98/Me. Please read the warning about editing the registry.

At the taskbar, click Start|Run. Type 'Regedit' and press Return. The registry editor opens.

Before you edit the registry, you should make a backup. On the 'Registry' menu, click 'Export Registry File'. In the 'Export Range' panel, click 'All', then save your registry as Backup.

Each user has a registry area named HKEY_USERS\[code number indicating user]\. For each user locate the entry:

HKU\[code number]\Software\Microsoft\Windows\CurrentVersion\Run\
wupdate
<Windows system folder>\wisvccz.exe

and delete it if it exists.

Close the registry editor.

Troj/Orse-B is a Windows Trojan.

Troj/Orse-B will attempt to download and execute component from remote website which at the time of writing is a copy of the Trojan.

Troj/Orse-B attempts to download configuration data from preconfigured websites which may instruct the Trojan to send emails.

When run the Trojan copies to Windows system folder as wisvccz.exe, drops zlbw.dll (also in the Windows system folder) and creates the following registry entry in order to run automatically on computer log on:

HKCU\Software\Microsoft\Windows\CurrentVersion\Run\
wupdate
<Windows system folder>\wisvccz.exe

zlbw.dll is a non-malicious ZLIB compression library.