Archive for the ‘Linux’ Category

Kali Tools

October 19, 2017 Leave a comment

# Check for rootkits on local system


Categories: Kali Linux, Uncategorized

portmap dead but subsys locked

October 19, 2017 Leave a comment

I have seen this issue and my feeling is it is a result of vulnerability scanners knocking the portmap service that handles the registration of systems for remote NFS, autofs.

Symptoms you may see:
Could not mount a user’s home directory:

su: warning: cannot change directory to /home/<user>: No such file or directory
# rpcinfo -p <nfs_server>
rpcinfo: can’t contact portmapper: RPC: Remote system error – Connection refused
# showmount -e
mount clntudp_create: RPC: Port mapper failure – RPC: Unable to receive

On NFS server if you see this error:

# service portmap status
portmap dead but subsys locked
# ll /var/lock/subsys/portmap    # If file exists, it has to be removed
# rm /var/lock/subsys/portmap
# service portmap restart
# rpcinfo -p
# service nfs restart    # Needs to be restarted to register with portmapper

Now, you should be able to run “rpcinfo -p <nfs_server>” from the NFS clients and mount the shares.


Categories: Linux, Redhat, Uncategorized

Kali SSH setup

October 17, 2017 Leave a comment

Move default keys to backup folder:
# cd /etc/ssh; mkdir backup_ssh; mv ssh_host_* backup_ssh
# dpkg-reconfigure openssh-server

Allow root to login
Edit /etc/ssh/sshd_config, add or change line to:
PermitRootLogin yes

Restart SSH
# service ssh stop; service ssh start; service ssh status

Kali Linux Updating Notes

October 17, 2017 Leave a comment

Run in a cron or in a shell script:
apt-get update && apt-get upgrade -y && apt-get dist-upgrade -y

apt-get install <package>
apt-get remove <package>
# List packages installed
dpkg -l
# list info about a package
apt-cache show <package>

# Repos where updates are retrieved

# Packages that speed up tools (may not be available for Kali 2.x)
apt-get install preload -y
# Increase privacy by removing temp files, cooks, caches, etc.
apt-get install bleachbit -y
# Remove unnecessary services; install Boot Up Manager
apt-get install bum -y
# Powers commands from keyboard
apt-get install gnome-do -y
# Search within apt system
apt-get install apt-file -y
# Deletion program that complies with govt standards
apt-get install scrub -y
# Capture screenshots of desktop
apt-get install shutter -y
# Print company name in header
apt-get install figlet -y
echo “figlet YOUR_COMPANY” >> ~/.bashrc

# Install TOR
apt-get install tor -y
# Edit /etc/proxychains.conf, change:
socks5 9050

# Start TOR service
service tor start
proxychains iceweasel



Categories: Kali Linux, Uncategorized

Samba CIFS mounts and securing user password

October 15, 2017 Leave a comment

Adding the code blocks below to /etc/rc.local:

mount.cifs //<host1>/share /<mount_point> -o ro,credentials=/root/.cifs.<host1>,remount

Option “remount” prevents double mounting of the same share.

File .cifs.<hostname> contains:


Categories: Linux, Redhat, Uncategorized

RHEL 6 IGMPv3 setting

August 11, 2017 Leave a comment

Set following parameter in /etc/sysctl.conf file for the interface that is desired (e.g. bond0, eth0, etc.).

  • Reboot system
Categories: Linux, Redhat, Uncategorized

Linux testing disk speed with dd

April 21, 2017 Leave a comment

Best way is to use dd and try the following:

dd bs=1M count=256 if=/dev/zero of=test conv=fdatasync

“fdatasync” tells dd to write physically to disk before providing the output. Increase to 1024, 2048 if you want 1G or 2G file size. Bigger sizing will produce a more normalized speed.

Categories: Linux, Redhat