3

I logged into a server as root and did w, this let me see that a user was editing a file.

someuser  pts/5    10.117.0.53      14:03    3:25   1.20s  1.14s vi somefile.py

Then I disconnected, and reconnected as root again later. I did a w again but this time it showed something different.

someuser  pts/5    10.117.0.53      14:03    5:20   0.20s  0.02s sshd: someuser [priv]

I can tell from the other fields that this is the same user, but this time what they're doing is hidden.

Why did it become hidden? How do I see what they're doing?

  • It looks as if the user just has a lingering SSH connection running. Why don't you email them and ask? – Kusalananda Feb 8 '18 at 20:03
  • I believe that's their ssh connection (a tunnel perhaps?), it may depend on the *nix version, I've seen some poor implementations of w , showing disconnected users, non-existing processes etc. Try a ps -t pts/5 to see if they have other processes attached to that terminal. – XrXca Feb 8 '18 at 20:08
  • There was a question here a few weeks ago (I can't find it now) about how w decides what command to show. It's heuristic. – Mark Plotnick Feb 8 '18 at 20:17
  • It's unix.stackexchange.com/questions/408719 . – JdeBP Feb 8 '18 at 20:56
4

If a user is using bash, you can add to his /etc/bash.bashrc:

readonly PROMPT_COMMAND='history -a >(logger -t "commandlog $USER[$PWD] $SSH_CONNECTION")'

This will log all the user commands to syslog.

I would configure syslogto forward the logs to a locked down central syslog server, so in case of hacking or a rogue sysadmin, they would not be able to tamper with evidence.

2

If auditd is enabled on the system, you can view the audit logs to see the command activity of users. This is a great resource that sysadmins regularly use when trying to forensically troubleshoot issues that might have been caused by other users actions with regard to the system.

1

You can try something simple like peeking at the users history file. This assumes that the user's shell is bash.

cat /home/someuser/.bash_history

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.