New (More) Annoying Microsoft Worm Hits Net

A new worm seems to be running rampant Unlike Code Red, it attempts to hit boxes with many different exploits (including what looks like an attempt to exploit boxes still rooted by Code Red). It looks like each IP tries 16 attempts on its neighbors. There is also a new mail worm mailing WAV files or something with bits of what appears to be the registry... it may or may not be related. Got any words on this? Shut down those windows boxes and stop opening attachments. And make that 21. Got another one while writing this story. All my hits are coming from 208.n.n.n (where I am) I'm sure it'll keep moving to nearby boxes. Update: 09/18 16:40 GMT by J : It now has a name: "Nimda." More info here, here, and here.

Here are examples of the requests it's sending:

GET /scripts/..%%35%63../winnt/system32/cmd.exe?/c+dir
GET /msadc/..%255c../..%255c../..%255c/..%c1%1c../..%c1%1c../ ..%c1%1c../winnt/system32/cmd.exe?/c+dir
GET /_vti_bin/..%255c../..%255c../..%255c../winnt/system32/cmd.exe?/c+dir

While writing this story I was hit a total of 4 times, 16 GET attempts per attack. In only 4 minutes. Also of interest, My desktop has now been hit about 500 times today, all from 208.x.x.x IPs. This might be really bad. I still haven't read anything about this anywhere else, so you heard it here first ;)

Update Web servers compromised by this worm apparently attach a "readme.eml" to all web pages served... and due to a bug in IE5, it will automatically execute the file! Yay Internet Explorer!

Comments

Info FromRuss at BugTraq

[Anonymous Coward]

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There have been numerous reports of IIS attacks being generated by machines over a broad range of IP addresses. These "infected" machines are using a wide variety of attacks which attempt to exploit already known and patched vulnerabilities against IIS.

It appears that the attacks can come both from email and from the network.

A new worm, being called w32.nimda.amm, is being sent around. The attachment is called README.EXE and comes as a MIME-type of "audio/x-wav" together with some html parts. There appears to be no text in this message when it is displayed by Outlook when in Auto-Preview mode (always a good indication there's something not quite right with an email.)

The network attacks against IIS boxes are a wide variety of attacks. Amongst them appear to be several attacks that assume the machine is compromised by Code Red II (looking for ROOT.EXE in the /scripts and /msadc directory, as well as an attempt to use the /c and /d virtual roots to get to CMD.EXE). Further, it attempts to exploit numerous other known IIS vulnerabilities.

One thing to note is the attempt to execute TFTP.EXE to download a file called ADMIN.DLL from (presumably) some previously compromised box.

Anyone who discovers a compromised machine (a machine with ADMIN.DLL in the /scripts directory), please forward me a copy of that .dll ASAP.

Also, look for TFTP traffic (UDP69). As a safeguard, consider doing the following;

edit %systemroot/system32/drivers/etc/services.

change the line;

tftp 69/udp

to;

tftp 0/udp

thereby disabling the TFTP client. W2K has TFTP.EXE protected by Windows File Protection so can't be removed.

More information as it arises.

Cheers,
Russ - Surgeon General of TruSecure Corporation/NTBugtraq Editor

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