Bionet is a backdoor - hacker's remote access tool. It's not so advanced as Sub7 or BackOrifice or Netbus backdoors. It consists of server and client parts. The server part is usually hiddenly installed on a victim's computer and it can be controlled by a client part from another (hacker's) computer when both systems are on Internet.
A victim usually gets infected with a server part by clicking on infected attachments that is sent to him by his on-line 'friends'. The server part when run gets installed as LIBUPDATE.EXE file into \Windows\ folder. It modifies Windows registry to be run during all windows sessions. Also the keylogging DLL named BNHOOK.DLL is dropped into the same folder.
The server part allows a hacker to perform the following actions on a remote system:
Open/close CD-Rom drive tray Capture screen of remote system Shutdown Window, reboot, power down a system Send messages to remote system and get replies Open file manager and execute, upload, download and delete files on remote system Show/hide Start button Set and trace position of mouse cursor on remote system Terminate certain applications Direct remote system webbrowser to any webpage Get server version info and remove it from a remote system Log all the events
To perform disinfection it is enough to delete the server part of this backdoor from a system. It's better to do it from pure DOS.
[Analysis: Alexey Podrezov; F-Secure Corp.; June 2001]