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

By: empulse
2009-03-30 15:48:24

What Others Think

On Ubuntu, it's /var/log/auth.log
goodevilgenius · 655 weeks and 4 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 · 655 weeks and 4 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 · 655 weeks and 4 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 · 655 weeks and 4 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 · 655 weeks and 4 days ago
BTW- /var/log/secure on Fedora-based systems, /var/log/auth.log in Debian-based systems.
atoponce · 655 weeks and 4 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 · 623 weeks and 3 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?

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