Someone using our ssh service for brute force attacks, what should we do?

August 15, 2017 816 views
Security Debian

We receive an email with a notice, that our ip has participated in brute-force activity,
We are ssh tunneling service providers, and like someone has used our service to do brute-force activity.
What we have to do.

this email from DigitalOcean

Hi there,

We’ve received a notification that one or more of your Droplets at 128.199.194.42 is participating in Brute-force activities. Please note that we may be required to take further action to prevent additional attacks, up to and including suspension of your Droplet. Should we take this step, we'll send an additional email notifying you that we have done this.

You can review the most recent report(s) we received at https://digitalocean.abusehq.net/share/EsFsAYXaHHit-BM2C2aozLPJJYPimxcxk1nednrN82I .

Additionally, you can review the abuse history of this incident at https://digitalocean.abusehq.net/share/RTiVbusRB3SP4GEi-Uj_AQ .

To resolve this matter, you’ll need to review the Droplet to determine the cause of the traffic. The system and application error and access logs may include additional details that could provide more insight on this. Additionally, reviewing your active processes could point to the responsible PID.

Once you’ve discovered the cause, please update this ticket letting us know what you determined to be the cause of the issue, how you resolved it, and what steps you took to prevent further events of a similar nature.

If you have any questions regarding this matter, please let us know.

Regards,

Trust & Safety,
Digital Ocean Support

ref:_00Do0IjOV._5001NRkqa6:ref

 
thank you
Sauufi team. Inc

3 Answers

Log users actions and then act upon blacklisting the user from your services. If you're running a service that allows others access to your servers then this is something you'll have to deal with on a daily basis (depending on its popularity). You could probably automate a script to ban a user if they show any signs of bruteforcing.

We do not know how to lock users, our ssh service can be used by everyone, so it's unlikely to find users who do that

You can help how to block this ip
He uses our squid proxy
to connect 168.95.6.55:25

1502823946.434  60622 220.129.157.109 TCP_MISS/503 0 CONNECT 168.95.6.55:25 - DIRECT/168.95.6.55 -
1502823946.434  60622 220.129.157.109 TCP_MISS/503 0 CONNECT 168.95.6.52:25 - DIRECT/168.95.6.52 -
1502823946.434  60622 220.129.157.109 TCP_MISS/503 0 CONNECT 168.95.5.17:25 - DIRECT/168.95.5.17 -
1502823946.434  60622 1.162.224.164 TCP_MISS/503 0 CONNECT 168.95.6.64:25 - DIRECT/168.95.6.64 -
1502823946.434  60622 1.162.224.164 TCP_MISS/503 0 CONNECT 203.69.82.35:25 - DIRECT/203.69.82.35 -

What software are you using for ssh tunneling?

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