Re: [Full-disclosure] sshd logins without a source

[Nikolaos Mitsis <drynhwyl@xxxxxxxxx>]

> At the time of the compromise I can see in each
> servers sshd logs an entry like the following:
>
> Sep 22 12:57:14 test-vm sshd[25002]: pam_unix(sshd:session): session
> opened for user root by (uid=0)
> Sep 22 12:57:32 test-vm sshd[25002]: pam_unix(sshd:session): session
> closed for user root
>

Have you checked the integrity of sshd binary? It could be replaced with a
copy that "forgets" to log so you don't get the sshd logs (possibly after
receiving a specified password).
However the above logs are from pam (pam_unix does the logging on behalf of
sshd) so it's not possible to disable this in the sshd binary itself.

cheers,
ν.

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