Ubuntu

hack my ubuntu system

Asked by aneesh

My friend had stole my ubuntu root password and access my ubuntu machine . Now he challenge me I could not stop his accessing . Even though I change my ubuntu root password he still can have access my machine through SSH. What is the method he used for it ? and how to prevent this ?

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Erik Meitner
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Best Erik Meitner (e.meitner) said : 		#1

Yes. He could have set up access via SSH public keys. With this he can login even though you changed the passwords for all the users on the machine. See how it is done:
http://www.debian-administration.org/article/SSH_with_authentication_key_instead_of_password

Try this command to see if there are any SSH public keys on your system : locate authorized_keys

Now the question is can root ssh to your box and if so, why? You should never allow this. Read this to see how to disable root ssh access:
http://www.debian-administration.org/article/Keeping_SSH_access_secure

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Tom (tom6) said : 		#2

Hi Erik?

Please could you add something to the Antivirus Communtiy Documentation about this? I added the links but don't understand SSH at all
https://help.ubuntu.com/community/Antivirus

Thanks and regards from
Tom :)

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actionparsnip (andrew-woodhead666) said : 		#3

Do you mean root or do you mean your account which is a member of the admin group?

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aneesh (aneesholv) said : 		#4

Thanks Erik Meitner, that solved my question.