From the SANS Internet Storm Center:
[snip]
Starting around 11:30 UTC, we've received several reports on a new worm variant that makes use of MS05-039 to spread. If you're not patched yet, this is your last call.
F-Secure named the critter "Zotob.A",Threats & Research Archives - F-Secure Blog
We've also received a submission of a binary called "pnpsrv.exe", which is recognized by ClamAV as Trojan.Spybot-123. Another reader has contributed evidence that a successful exploit by Zotob.A (or variant)
The worm will download the main payload from the infecting machine. Once a machine is infected, it will become an ftp server itself. It will scan for open port 445/tcp. Once it finds a system with port 445 listening, it will try to use the PnP exploit to download and execute the main payload via ftp.
Important facts so far:
- Patch MS05-039 will protect you
- Windows XP SP2 and Windows 2003 can not be exploited by this worm, as the worm does not use a valid logon.
- Blocking port 445 will protect you (but watch for internal infected systems)
- The FTP server does not run on port 21. It appears to pick a random high port.
[snip]
- ferg