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May 19, 2015 - A Look At The New Commandlinefu
I've put together a short writeup on what kind of newness you can expect from the next iteration of clfu. Check it out here.
March 2, 2015 - New Management
I'm Jon, I'll be maintaining and improving clfu. Thanks to David for building such a great resource!

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Psst. Open beta.

Wow, didn't really expect you to read this far down. The latest iteration of the site is in open beta. It's a gentle open beta-- not in prime-time just yet. It's being hosted over at UpGuard (link) and you are more than welcome to give it a shot. Couple things:

  • » The open beta is running a copy of the database that will not carry over to the final version. Don't post anything you don't mind losing.
  • » If you wish to use your user account, you will probably need to reset your password.
Your feedback is appreciated via the form on the beta page. Thanks! -Jon & CLFU Team

Find brute force attempts on SSHd

Terminal - Find brute force attempts on SSHd
cat /var/log/secure | grep sshd | grep Failed | sed 's/invalid//' | sed 's/user//' | awk '{print $11}' | sort | uniq -c | sort -n
2009-03-30 15:48:24
User: empulse
Functions: awk cat grep sed sort sshd uniq
Find brute force attempts on SSHd

Searches the /var/log/secure log file for Failed and/or invalid user log in attempts.


There are 3 alternatives - vote for the best!

Terminal - Alternatives

Know a better way?

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What others think

On Ubuntu, it's /var/log/auth.log

Comment by goodevilgenius 429 weeks and 3 days ago

cat overload! :-)

< /var.log/secure grep sshd | grep Failed | sed 's/invalid//' | sed 's/user//' | awk '{print $11}' | sort | uniq -c | sort -n

Comment by mpb 429 weeks and 3 days ago

I was wondering why have the sed commands? Wouldn't just making awk '{print $13}' make more sense? I'm a bash newbie and would love the explanation.

Comment by frailotis 429 weeks and 3 days ago

After messing around, here's what I've got and I think it's a bit cleaner. Let me know if that's true or not.

awk '/sshd/&& /Failed/ {print $13}' /var/log/secure | uniq -c | sort -nr

Comment by frailotis 429 weeks and 3 days ago

@frailotis you need to sort first before piping to uniq, Also, you're missing some IP addreses and getting random data by not searching and replacing for "invalid user". However, yes, people need to learn awk rather that pipe cat to grep to grep to sed to sed then to awk, with sort used twice!

awk '/sshd/ && /Failed/ {sub(/invalid user/,""); print $11}' /var/log/auth.log | sort -n | uniq
Comment by atoponce 429 weeks and 3 days ago

BTW- /var/log/secure on Fedora-based systems, /var/log/auth.log in Debian-based systems.

Comment by atoponce 429 weeks and 3 days ago

You can make the original command a little cleaner by combining sed expressions like this:

cat /var/log/messages | grep sshd | grep Failed | sed -e 's/invalid// ; s/user//' | awk '{print $11}' | sort | uniq -c | sort -n
Comment by unixmonkey6951 397 weeks and 2 days ago

Your point of view

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