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
Searches the /var/log/secure log file for Failed and/or invalid user log in attempts.
Sample Output 
2 67.11.200.144
      4 210.40.128.31
      6 208.71.128.195
      6 64.39.0.38
     15 219.246.112.241
     20 200.214.15.142
     30 119.70.154.57
     30 79.38.22.92
     40 61.152.201.74
     87 88.191.94.168
    107 200.27.214.30
    107 61.134.27.234
    115 200.6.208.186
    170 222.73.37.25
    387 99.154.226.153
    548 222.35.78.224
    627 94.75.240.141
    946 213.191.111.5

8
By: empulse
2009-03-30 15:48:24
awk cat grep sed sort sshd uniq
7
Submit An Alternative

What Others Think

On Ubuntu, it's /var/log/auth.log
goodevilgenius · 871 weeks and 5 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
mpb · 871 weeks and 5 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.
frailotis · 871 weeks and 5 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
frailotis · 871 weeks and 5 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
atoponce · 871 weeks and 5 days ago
BTW- /var/log/secure on Fedora-based systems, /var/log/auth.log in Debian-based systems.
atoponce · 871 weeks and 5 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
unixmonkey6951 · 839 weeks and 4 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

You must be signed in to comment.

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands

Similar Commands

Block all IP addresses and domains that have attempted brute force SSH login to computer

display systemd log entries for sshd using "no-pager" (a bit like in pre-systemd: grep sshd /var/log/messages)

Stop Flash from tracking everything you do.

Patator: A Hydra brute force alternative

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: