May 26, 2018
Script to thwart ssh attacks
DenyHosts is a script intended to be run by *ix system administrators to help thwart ssh server attacks.
If you’ve ever looked at your ssh log /var/log/auth.log you may be alarmed to see how many hackers attempted to gain access to your server. Denyhosts helps you
- Parses /var/log/auth.log to find all login attempts
- Can be run from the command line, cron or as a daemon new in 0.9
- Records all failed login attempts for the user and offending host
- For each host that exceeds a threshold count, records the evil host
- Keeps track of each non-existent user eg. sdada when a login attempt failed.
- Keeps track of each existing user eg. root when a login attempt failed.
- Keeps track of each offending host hosts can be purged
- Keeps track of suspicious logins
- Keeps track of the file offset, so that you can reparse the same file
- When the log file is rotated, the script will detect it
- Appends /etc/hosts.allow
- Optionally sends an email of newly banned hosts and suspicious logins.
- Resolves IP addresses to hostnames, if you want