iwconfig - check wireless setup
dmesg - query a USB device, plug it in a type this command
lspci - chipset interrogation
lsusb - as above
Search
Tuesday, 17 August 2010
Configure Open SSH securely
Modify config in /etc/ssh or ssh_config to disable support for legacy protocols. Look for the 'Protocol 2,1' line and remove the ver 1 protocol.
Also set 'PermitRootLogin no' and 'MaxAuthTries 3'
After the changes have been made run:
service ssh restart
View attack activity by looking at /var/log/auth. If you see a particular IP that keeps attacking, put an entry in /etc/hosts.deny
You can automate this process by installing the DenyHosts package. Edit it's config in /etc/denyhosts.conf and change DENY_THRESHOLD_INVALID from 5 to 2
Also set 'PermitRootLogin no' and 'MaxAuthTries 3'
After the changes have been made run:
service ssh restart
View attack activity by looking at /var/log/auth. If you see a particular IP that keeps attacking, put an entry in /etc/hosts.deny
You can automate this process by installing the DenyHosts package. Edit it's config in /etc/denyhosts.conf and change DENY_THRESHOLD_INVALID from 5 to 2
Quick port scan of a machine
nmap
Not installed by default on Ubuntu or Mint, use:
sudo apt-get install nmap
Not installed by default on Ubuntu or Mint, use:
sudo apt-get install nmap
Change hostname in linux
Using suitable privelages, navigate to /etc and edit the following files, replacing the default name with your desired machine name. Prefereably the FQDN.
/etc/hosts
/etc/hostname
/etc/hosts
/etc/hostname
Thursday, 8 July 2010
Tika and Solr
To index Word, Excel, PDF and other "unstructured" documents, Solr uses Tika, another Apache project.
Tika comes bundled in Solr and is ready to run in Solr. However, if you want to run Tika individually you have to copy a few .jar files around.
cd [Your path]/apache-solr-nightly/lib cp commons-io-1.4.jar commons-codec-1.3.jar [Your path]/apache-solr-nightly/example/solr/lib cp ~/.m2/repository/org/jempbox/jempbox/0.2.0/jempbox-0.2.0.jar [Your path]/apache-solr-nightly/example/solr/lib
java -jar tika-0.2.jar
ConfigIf you want to index Word, Excel, PDF, and other types of documents, there is a bit of additional configuration to do. To index those files types you have to get a nightly build of Solr from here, and copy some files and directories as described in the link at the end of this post. You have to add the following lines to example/solr/conf/solrconf.xml:
last_modified
true
Monday, 28 June 2010
Bitnami Stacks
Just discovered these and they are pretty awesome. If you just want to test a Wordpress idea and don't want to build a whole VM then download a stack:
http://bitnami.org/stack/wordpress
http://bitnami.org/stack/wordpress
Wednesday, 5 May 2010
Linux logs - just so I remember
Most logs are stored in the /var/log/ directory
Over a period of time log files grow too large and are rotated, with the older logs being compressed and appended with .gz
Rotation is handled by the logrotate utility which is governed by the /etc/logrotate.conf file
The /etc/logrotate.d directory contains configs for individual log files such as apt etc.
Over a period of time log files grow too large and are rotated, with the older logs being compressed and appended with .gz
Rotation is handled by the logrotate utility which is governed by the /etc/logrotate.conf file
The /etc/logrotate.d directory contains configs for individual log files such as apt etc.
Thursday, 29 April 2010
Linux detective work
When looking at logs, if an attack has taken place and the IP can be discovered of the attacking machine, then it is possible to reverse trace the attacker and potentially find out their pc details, open ports, isp etc.
From linux, open a bash terminal:
dig -x 1.2.3.4
Where 1.2.3.4 is an IP address. This command may return a pointer record. Next, try a whois:
whois 1.2.3.4
This command should give the netblock owner, ISP etc. You can also try using the commands available at www.robtex.com
Finally, try an nmap command:
nmap -O 1.2.3.4
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