Security Incidents mailing list archives
Re: compromised machines
From: Harlan Carvey <keydet89 () yahoo com>
Date: Fri, 27 Aug 2004 03:41:20 -0700 (PDT)
We cleaned up all of these machines and rebuilt each of them from scratch, with all the latest patches. The IDS/IPS at the edge of our network, does not seem to be catching the bots which are causing these.
When you say IDS/IPS, which are you referring to? If IDS, remember...they are signature-based. One of the biggest problems with employing such a technology is not understanding that it only detects those things that it has signatures for...
After one week, I have 50 machines which are compromised by the same bot, and some of them are the same as the previous list of machines.
That tends to happen in situations in which no root cause analysis was done.
Now a host-based firewall is a very tough option for us, since we are a university with around 30,000 computers and under different departments. Does anyone know what bots are causing these and any IDS signatures for these.
Well, given the banner you provided, it would seem that you could write one of your own. Does your IDS product provide the facility for such a thing?
We are using a couple of IDS such as snort and Dragon and Intrushield, Any help for this is appreciated.
My earlier question was rhetorical...
I did have a look at one of these machines and from what I see, there are a couple of files which seem to be causing this. there is a csmss.exe file which is listening on the port 6544.. The machine is also running a remote server. before csmss.exe, a file ServNT.exe seems to have been executed, which might have caused a sequence of events.. there is a batch file , which using the registry runs a remote admin server at startup. then we got a number of files which are used to show the banner, hide the files . If I could find out how did they get inside the system, because most of the infected machines were running fully patched Windows XP with latest Norton Antivirus definitions.?
Patches aren't the be-all-and-end-all...there's more to security than that. There are other avenues into systems such as email and the browser...avenues that may not be covered by patches.
All of those machines are running either Windows 2000 professional or XP professional. 2 machines wer analysed, one of which was completely ptched and had all the latest virus definitions from Norton, another machine was not patched and no virus updates were present.. But the state of affairs at both the machines was the same.. themessage sent before contains the details.. on more analysis, I found csmss.exeto be a part of W32.Dedler Trojan.. but how it got inside the system is anyone's guess..
Perhaps not...I went to the Symantec site and looked up "Dedler"...it's not a Trojan...it's a worm. http://securityresponse.symantec.com/avcenter/venc/data/w32.dedler.worm.html Interesting thing about the write-up at the site: "4. Copies the following files to open network shares:" There wasn't any detail in your description regarding your domain setup, but maybe that helps a little bit in explaining how so many systems were infected. I know the Symantec writeup doesn't jive exactly with your description, but based on what Norton detected, it's a start. It might also go toward explaining why so many machines were reinfected...
None of them was running IIS.
Ok...I'm not sure where that plays into all this...but ok... Good luck.
Current thread:
- compromised machines Varun Pitale (Aug 26)
- Re: compromised machines Brian Eckman (Aug 27)
- Re: compromised machines Scott Weeks (Aug 27)
- Re: compromised machines Mike Lyman (Aug 30)
- Re: compromised machines bob (Aug 31)
- Re: compromised machines Mike Lyman (Aug 30)
- Re: compromised machines Harlan Carvey (Aug 27)
- Re: compromised machines Michael H. Warfield (Aug 30)
- Re: compromised machines Jose Maria Lopez (Aug 30)
- <Possible follow-ups>
- Re: compromised machines soccer4net () netzero com (Aug 27)