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Check for login failures and summarize

Terminal - Check for login failures and summarize
zgrep "Failed password" /var/log/auth.log* | awk '{print $9}' | sort | uniq -c | sort -nr | less
2009-03-03 13:45:56
User: dbart
Functions: awk sort uniq zgrep
8
Check for login failures and summarize

This command checks for the number of times when someone has tried to login to your server and failed. If there are a lot, then that user is being targeted on your system and you might want to make sure that user either has remote logins disabled, or has a strong password, or both. If your output has an "invalid" line, it is a summary of all logins from users that don't exist on your system.

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What others think

apt-get install denyhosts # for the win

Comment by linuxrawkstar 295 weeks and 2 days ago

if you want to see the list of invalid users attempted login against your system

zgrep "Invalid user" /var/log/auth.log* | awk '{print $8}' | sort | uniq -c | sort -nr | less
Comment by starchox 295 weeks and 1 day ago

That's a lot of pipes.

Comment by Buzzcp 257 weeks ago

@starchox, even better:

zgrep "Invalid user" /var/log/auth.log* | awk '{print $8 " " $10}' | sort | uniq -c | sort -nr | less
Comment by Buzzcp 257 weeks ago

Your point of view

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