Sadmind

Summary

Sadmind is a worm, that propagates from a Sun Solaris machine to another. It also compromises Windows NT/2000 servers running Internet Information Server 4.0 or 5.0.

Disinfection & Removal

Allow F-Secure Anti-Virus to disinfect the relevant files.

For more general information on disinfection, please see Removal Instructions.

Technical Details

Variant:Sadmind.A

The worm uses an old vulnerability in the Solaris operating system to enter the system. In the system it first opens remote shell (rsh) service for the root user. It then extracts itself to "/dev/cuc" directory, and adds a worm startup code to the "/etc/rc2.d/S71rpc". The worm also attempts to download and install Perl on the system, and starts itself by executing "/dev/cuc/start.sh" on the victim using the rsh service.

"start.sh" creates a directory "/dev/cup", and starts worms main processes in the background.

The worm goes through random Class-B subnets looking for unpatched Windows NT/2000 machines running IIS web server. If a vulnerable machine is found, the worm will copy the "\winnt\system32\cmd.exe" to "wwwroot\scripts\root.exe" directory and replace "index.htm", "index.asp", "default.htm" and "default.asp" files with its own.

Sadmind also looks for vulnerable Solaris systems from randon Class-B networks. If a vulnerable host is found, the worm creates a tar archive "uni.tar" out of itself, and sends it to the victim using rsh service.

Both vulnerabilities have been fixed by vendors.

Futher information about the problem and the fix in sandmind service in Solaris is available from Sun: http://sunsolve.sun.com/pub-cgi/retrieve.pl?doctype=coll&doc=secbull/191&...

Further information about the IIS unicode vulnerability, including a fix, is available from Microsoft at: http://www.microsoft.com/technet/security/bulletin/MS00-078.asp and additional information at: http://www.microsoft.com/technet/security/bulletin/MS00-086.asp

Technical Details: Sami Rautiainen, F-Secure; May 2001