Beast (trojan horse)

Beast is a Windows-based backdoor trojan horse, more commonly known in the underground "script-kiddie" community as a Remote Administration Tool. It is capable of infecting version of Windows from 95 to XP. Written in Delphi and released first by its author Tataye in 2002, it became quite popular due to its unique features. It used the typical client–server model where the client would be under operation by the attacker and the server is what would infect the victim. Beast was one of the first trojans to feature a reverse connection to its victims, and once established it gave the attacker complete control over the infected computer. Using the reverse connection there was no need for the attacker to know the target IP address; instead, the server connected to a predefined DNS, which was redirected to the attacker IP address. For its DLL, it used the injection method—they were injected into a specified process, commonly "explorer.exe" (Windows Explorer), "iexplore.exe" (Internet Explorer), or "msnmsgr.exe" (MSN Messenger). Due to this the DLLs were automatically loaded into memory once these processes were executed.

It mainly targeted three infection sites:

• C:\Windows\msagent\ms****.com (Size ranging from 30KB to 49KB)
• C:\Windows\System32\ms****.com (Size ranging from 30KB to 49KB)
• C:\Windows\dxdgns.dll or C:\Windows\System32\dxdgns.dll (Location dependent on attacker's choice)

(Note: Removing these three files in safe mode with system restore turned off in case of XP would thus disinfect the system)

The default ports used for the direct and reverse connections were 6666 and 9999 respectively, though the attacker had the option of changing these. Beast came with a built-in firewall bypasser and had the ability of terminating some Anti-Virus or firewall processes. It also came with a binder that could be used to join two or more files together and then change their icon.

The Server Editor offered these capabilities:

• Direct or Reverse connection option
• DLL injection location (e.g. explorer.exe)
• Server name change option
• Server installation directory (e.g. <windir>)
• Various IP and Server info notification options (e.g. email, icq, cgi, etc.)
• Startup keys selection
• Anti-Virus and firewall killing
• Other miscellaneous options (e.g. automatic server file deletion, fake error messages, offline keylogger, icon changer, etc.)

Once connected to the victim, Beast offered the following features:

• File Manager – along with browsing victim's directories it could upload, download, delete, or execute any file
• Remote Registry Editor
• Screenshot and Webcam capture utility
• Services, Applications, and Processes Managers, providing the ability of terminating or executing any of these
• Clipboard tool that could get currently stored strings
• Passwords tool capable of recovering any stored passwords in the victim's computer
• Power Options (e.g. shutdown, reboot, logoff, crash, etc.)
• Some tools mainly for creating nuisance (e.g. mouse locking, taskbar hiding, CD-ROM operator and locker, URL opener, wallpaper changer, etc.)
• Chat client providing communication between the attacker and the victim
• Other tools such as a Remote IP scanner, live keylogger, offline logs downloader, etc.
• Server Controls (e.g. server deleter, updater, terminator, info provider, etc.)

See also

• Reverse connection