This looks pretty much like a NIMDA worm probe (more advanced variant of
code red) attempting to exploit known IIS vulnerabilities . Code Red
probes are similar and are recognisable by XXXXXXXXXXX or NNNNNNNNNN
patterns in the access_log .

The Apache http service running on my home linux server has been logging
this sort of crap since September last year.

My initial trace attempts when I first came across it, revealed that
only a minority of source IP addrs resolved to a valid host with open
ports for common services. Most addresses looked like reassigned Dynamic
IP s and many failed reverse DNS lookup. 

When I researched this on the net last year, I found the approaches from
linux users varied from ignoring it completely to implementing various
forms of automated counter measures, including scripts that scan httpd
logs, detect an attack and add then add firewall rules to block the
offending host. Some people even proposed attempting to reverse the
exploit i.e. on the assumption that the attacking host has an infected
IIS server, exploit the worm itself to disable the server in some way .
Try a google search with key words such as NIMDA, apache, linux etc. for
more info.

I chose to simply tolerate and ignore these probes for now .

My only real concern relates to possible *invalid* over limit traffic
charges from my ISP. 

My linux server is online roughly 24/7 (not quite 5 nines yet :-) ) to a
TelstraClear/paradise  256Kb/128Kb cable connection, which has a 5GB per
month traffic limit . Needless to say I keep a close watch on the fairly
detailed usage logs that paradise provide . The paradise web interface
allows you to drill down to individual usage line items, which detail
time for each 'usage' and charge in terms of international MB
equivalents. My concern arose when I noticed a lot of 0.01 MB charges at
unusual times from various oddball IP addresses. Correlation with my
apache access logs showed that most of these 0.01MB charges were the
result of incoming NIMDA probes. Now, although I haven't proved it, I
suspect that a NIMDA probe doesn't generate 10Kb worth of traffic.

Does anyone know how paradise or T/C bills for short bursts of traffic,
is there a threshold or some form of consolidation ? If this type of
billing isn't being done fairly, given a sufficient number of such
attacks, there is the danger of falsely exceeding traffic limits and
over billing due to rounding errors.

To exemplify that this possibly does happen - a Paradise cable user with
a 256Kb cable connection (same as mine) recently reported (on nz.comp)
that he was billed for 5GB of traffic over a 5 minute period (1GB per
minute on a 256KB connection - yeah right). He was told that this was
'probably' caused my a smurf DOS attack . That report served to
strengthen my suspicions. 


+I am currently 'playing' with apache, does anyone here ever
+get tired of;
+
+<snip>
+[Wed Jan 30 15:30:59 2002] [error] [client 210.74.146.190]
+File does not 
+exist: /somedir/scripts/root.exe
+[Wed Jan 30 15:31:01 2002] [error] [client 210.74.146.190] 
+File does not 
+exist: /somedir/MSADC/root.exe
+[Wed Jan 30 15:31:03 2002] [error] [client 210.74.146.190] 
+File does not 
+exist: /somedir/c/winnt/system32/cmd.exe
+[Wed Jan 30 15:31:05 2002] [error] [client 210.74.146.190] 
+File does not 
+exist: /somedir/d/winnt/system32/cmd.exe
+[Wed Jan 30 15:31:06 2002] [error] [client 210.74.146.190] 
+File does not 
+exist: /somedir/scripts/..%5c../winnt/system32/cmd.exe
+[Wed Jan 30 15:31:08 2002] [error] [client 210.74.146.190] 
+File does not 
+exist: /somedir/_vti_bin/..%5c../..%5c../..%5c../winnt/system32/cmd.exe
+[Wed Jan 30 15:31:10 2002] [error] [client 210.74.146.190] 
+File does not 
+exist: /somedir/_mem_bin/..%5c../..%5c../..%5c../winnt/system32/cmd.exe
+[Wed Jan 30 15:31:12 2002] [error] [client 210.74.146.190] 
+File does not 
+exist: 
+/somedir/msadc/..%5c../..%5c../..%5c/..�^\../..�^\../..�^\../wi
+nnt/system32/cmd.exe
+</snip>
+
+I mean this attack was directed at an NT/2k/XP machine.  I
+have whois'ed the 
+IP and have someone to complain to, what is the general attitude here 
+towards responding to provocation such as this?
+
+I do realise that .190 is not a specific address and will
+probably not be 
+traceable back to the purpotrating computer.  But someone 
+needs a good stiff 
+slaping with a dripping wet trout.
+
+Mark Carey
+
+
+
+
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