[support] Strange thing happened in my site - virus attack(?)

[Kim, Soonho (IFPRI)]

Dear all,

I found something strange happened in my site. As you see the attached, a user named "Anonymous" tried to update wiki pages every day. 
The wiki page is only accessed by a certain user group (definitely not "Anonymous" user).  What "Anonymous" have done was just to un-publish page. 
Is there anyone who is familiar with this strange case? Is there any way to delete the user and to protect this?

Thanks so much for your help in advance. 

Best Regards,
Soonho

 

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