I need help writing a query that finds the username of whoever ran a command on A Linux server.
For example, if you look at the log below:
<86>Mar 5 18:41:44 server1 useradd: new user: name=test1, UID=1100, GID=5020, home=/home/test1, shell=/bin/bash
Someone with the session ID=2569 added a new user "test1".
If I run another query like this: "pid=2569 eventtype=ssh_open", I can see to whom that session belongs.
<86>Jan 24 18:34:03 test1 sshd: pam_unix(sshd:session): session opened for user admin by (uid=0)
I was trying to write a query like this, but I keep hitting the wall :
| stats values(pid) AS pid1]
[search index="linux_secure" eventtype=ssh_open | stats values(pid) AS pid2]
| where pid1=pid2
The query above is not correct, and it returns errors like subsearch 1 contains a non-streaming command.
I want to write something that checks for the identical pid and extracts the username from search2 and the action from search 1.
Any help would be appreciated.
This assumes that the one type uses
user and the other uses
name; if not, you will have to fix that part; otherwise this:
index="linux_secure" AND eventtype="useradd" | eval earliest = _time - (10 * 60) | map search="search index=\"linux_secure\" AND eventtype=\"ssh_open\" earliest=$earliest$ latest=$_time$ pid=$pid$ | eval name=$name$, addtime=$_time$ | table _time addtime pid name user"
index="linux_secure" (eventtype="useradd" OR eventtype="ssh_open") | stats dc(eventtype) AS eventtype_count values(name) AS name values(user) AS user BY pid | where eventtype_count >1
Thank you @woodcock for the above queries.
Query number two, return pid, eventtype_count, name ( which is the user that has been added), and user (which is also has the same value as name or it's null).
I really like query number 1, but for some reason, I can't get it to work.
first, it complained about the latest time, I added the latest time but then it did not return anything.
@woodcock I wanted to thank you again for helping me with this.
I was reviewing the logs and realized that linux_secure logs are not the best option to do this.
I will consider doing this by using Linux Audit logs.
index="linux_secure" (eventtype=useradd OR eventtype=ssh_open) | rex "new user: name=(?<adduser>[^,]+)" | stats dc(eventtype) as flag values(adduser) as adduser values(admin) as admin by pid | where flag >1 and isnotnull(adduser)
I see, this query wii display user name who use useradd command and admin.
I'm not sure your field extraction, I keep
Thank you @to4kawa,
But this query will return all the users who also login but did not run the useradd command.
I'm only looking to find users who ran that command.
Some users have logged in to the systems a long time ago, and they are running commands, the only way for me to map them is by using their pid.
I did a field extraction before, so we don't need this part: | rex "new user: name=(?[^,]+)"
So, with this query now I'm getting the pid and the user that has been added. But I don't get the username of the user who logged in in ssh_open event and ran that command.
This is what I'm getting:
pid adduser flag
2569 test1 2
I want to extract the admin field from ssh_open, then we can now to whom that pid belongs.