Login auditing

Sat Jun 19 18:51:20 2004 Login auditing

Posted by Tony Lawrence

An interesting thread in comp.unix.sco.misc :

Logging failed logins discusses some aspects of monitoring and logging login failures.

That's SCO related, but modern Windows systems can also track bad logins and incorrect password attempts: Logging Failed Log-in Attempts (Windows 2003 Server)

Linux has a nice faillog command and lastb also (note that you need to create the "btmp" file first for "lastb" and faillog needs "faillog"). Neither of those record anything about ssh logins.

The sshd (secure shell daemon) logs using syslog, but early versions didn't record unsuccessful logins for up to four attempts - effectively hiding password guessing attempts (see http://www.crimelabs.net/docs/sshd1-logging.txt). Normally you'd find these in /var/log/messages and could extract them easily:

# grep "Failed password" messages
Jun 19 14:17:52 mail sshd[17194]: Failed password for tony from 64.226.42.29 port 2920
Jun 19 14:18:38 mail sshd[17199]: Failed password for tony from 64.226.42.29 port 2933
Jun 19 14:19:10 mail sshd[17249]: Failed password for tony from 64.226.42.29 port 2941
Jun 19 14:19:11 mail sshd[17249]: Failed password for tony from 64.226.42.29 port 2941



 

Unix systems usually have the ability to lock out users or terminals after so many failed login attempts. In fact, accidental lockouts come up quite often on SCO systems: Command line unlock ttys and users- user login unlock. Linux systems can do the same thing with the PAM pam_tally module: http://www.baverstock.org.uk/tim/pam/index.html and http://www.kernel.org/pub/linux/libs/pam/Linux-PAM-html/pam-6.html#ss6.24

My Unix/Linux Troubleshooting Book

My Hard Truths about Easy Money Book

My Self Employment Book

Jump to Comments

Many of the products and books I review are things I purchased for my own use. Some were given to me specifically for the purpose of reviewing them. I resell or can earn commissions from the sale of some of these items. Links within these pages may be affiliate links that pay me for referring you to them. That's mostly insignificant amounts of money; whenever it is not I have made my relationship plain. I also may own stock in companies mentioned here. If you have any question, please do feel free to contact me.

Specific links that take you to pages that allow you to purchase the item I reviewed are very likely to pay me a commission. Many of the books I review were given to me by the publishers specifically for the purpose of writing a review. These gifts and referral fees do not affect my opinions; I often give bad reviews anyway.

We use Google third-party advertising companies to serve ads when you visit our website. These companies may use information (not including your name, address, email address, or telephone number) about your visits to this and other websites in order to provide advertisements about goods and services of interest to you. If you would like more information about this practice and to know your choices about not having this information used by these companies, click here.