[Ubuntu 16.04.4 LTS] Most of my basic command suddenly not working (apt,etc)

[cimani]

Hello

i don't know what happening ,but my server acting really weird in the last 3 days

maybe friend of mine doing something to the server or maybe got hacked

2 days ago there's additional open port which i didn't recognize (port 9090)

sudo apt-get
web server (port 80)

when i run this command

sudo apt-get *

the cli return this

sudo: apt-get: command not found

i have no idea why this happen (im a windows user)

but in bash history i saw this line is executed

sudo apt-get --purge remove libstdc++6

This is my server detail

No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 16.04.4 LTS
Release:        16.04
Codename:       xenial

[wyliecoyoteuk]

libstdc++6 is a c++ runtime library, which is needed for your commands.
Can you run dpkg?
If so you can reinstall the lost package
https://askubuntu.com/questions/8187...lso-breaks-apt
If there is an additional port, I would close it and investigate, you may well have been hacked.
https://www.speedguide.net/port.php?port=9090

[Impavidus]

Just checking on 18.04, there's a huge load of packages (including apt) depending on libstdc++6. I'm not sure it's the same on 16.04 (some may still depend on an older version, like libstdc++5), but I'm surprised the computer still works, more or less. But the fact that the command appears in the bash history doesn't guarantee that libstdc++6 and everything depending on it were actually removed. The person running the command may have aborted.

To see what was actually removed, read your logs:

grep "purge\|remove" /var/log/dpkg.log

You may have to check older log files too, in the same directory. You can do this from a live disk, if necessary. In that case, mount the partition with your log files and change the path in the command accordingly.

If you consider being hacked a serious possibility, wipe your hard drive, reinstall and restore your files from backups made before these strange things happened.