When I did a seach in google, I found this trojan LVK4 (http://www.hut.fi/~jjkleimo/kurssit/tik110452/examples_rootkit.html). Looks like my box has the same behavior as LVK4 installed.
I did a /sbin/ifconfig and got the following result:
[root@server1 bin]# /sbin/ifconfig
eth0 Link encap:Ethernet HWaddr 00:90:27:43:87:D7
inet addr:10.10.10.19 Bcast:10.10.255.255 Mask:255.255.0.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:67632 errors:0 dropped:0 overruns:0 frame:0
TX packets:58572 errors:0 dropped:0 overruns:0 carrier:1
collisions:4651 txqueuelen:100
Interrupt:10 Base address:0xa000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:33 errors:0 dropped:0 overruns:0 frame:0
TX packets:33 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
I did a netstat and got the following:
netstat
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 20 10.10.10.19:ssh 1xx.41.128.54:779 ESTABLISHED
tcp 0 0 10.10.10.19:ssh 1xx.41.128.54:709 ESTABLISHED
tcp 0 0 10.10.10.19:22316 minotor.spale.com:ircd ESTABLISHED
First two ssh are established by me. But where does this ircd come from?
Anyone has this kind of problem before?
After I got the advice from David (Thanks. David. That's pretty quick. I was still debuging my box when your answer came up.) , I downloaded the sash and tar xvzf into my box. After "make install", I tried "su nsadmin -lc sash" in the sash folder. I was prompted with "Stand-alone shell (version 3.4)
>".
Then I tried several command and got the following info:
> ls
ls: Permission denied
> ps awux | grep nsd
sh: /bin/ps: Permission denied
> ls /lib
ls: Permission denied
> locate libshow
locate: Permission denied
Then I came across with this article http://online.securityfocus.com/archive/75/249597. I did check the system, following the instruction. I didn't find libshow.so on my box.
The following are ports open in my box:
The following ports are allowed incoming all ports are allowed outgoing:
TCP/5190 AOL Browser
TCP/8000 AOL Server
TCP/53 DNS
TCP/21 FTP
TCP/80 HTTP
TCP/443 HTTPS
TCP/8443
TCP/110 POP3
TCP/25 SMTP
TCP/22 SSH
TCP/23 TELNET
UDP/53
UDP/22
I did use ws_ftp to upload my file from windows box to this server. I guess that's where my password was sniffed.
Any idea?
Jay