Linux Server Intrusion Analysis report

One day, received a call from friends, their company's Web server was complained of sending http://www.aliyun.com/zixun/aggregation/12915.html "> spam, request urgent treatment, friends let me go over to help him check." I was puzzled how the Web server sent spam, and my friend told me that the mail service was not installed on the Web server system and it should be impossible to send spam. The gut tells me maybe someone hacking me?

I went to a friend of the company's room, using SECURECRT Landing to the server, PS, found that there are several abnormal procedures, as shown in the following figure, there is a sendmail program, there is an abnormal screen program. It must be dark and busy.

Figure I: Ps–aux discovery of the exception process

Look at it with a netstat–an, find the strange port 1985, there is a/dev/gpmctl data stream, has not before.

Figure II: Netstat–an See anomalies

Come to the Var directory, look at the secure log, this look, it does not matter, a look scared, the log shows that from October 9 11:01:22 until 03:37:33 October 10, the user of the machine for the brutal misuse of SSH, And from the log you can see the weak password to test the account is not a machine, but from a few different machines, they are

140.123.230.* (Taiwan)
211.173.47.* (Korea)
164.164.149.* (India)
210.118.26.* (Korea)
217.199.173.* (UK)
218.5.117.* (Quanzhou, Fujian)
211.90.95.* (Jiangsu Unicom)

So many machines do distributed collaboration to find weak passwords on machines, it seems that if you want to verify the source is more difficult, it is zombie network zombie machine, and there is a Fujian Quanzhou ADSL dial-up account and the user of Jiangsu Unicom, to verify the words must start from it to check, oh, unfortunately I am not forensics experts, Just put it aside for verification.

Figure three:/var/log/secure See SSH login log

With the last log look at the past landing records, the following figure four shows, you can see from the domain name Floman2.mediasat Landing, with Nslookup query unexpectedly find this domain name.

Figure IV: Last log