Monday, March 7, 2016

Infinite loop on the command line using Python

Infinite loop on the command line using Python:

python -c "exec(\"import os\\nwhile True: os.system('.//prog')\")"

python -c "exec('import os\\nwhile True: os.system(\"./prog\")')"

(echo "import os" ; echo "while True: os.system('.//prog')") | python

Saturday, October 23, 2010

Install Clamav on Fedora

I decided this morning to install antivirus on my desktop running Fedora 13.
I had to do some looking around before I finally got it installed.
yum install clamav-scanner
yum install clamav-update

cp /usr/share/doc/clamav-server-0.96.1/clamd.conf /etc/clamd.conf

vim /etc/clamd.conf /etc/freshclam.conf

Follow the instructions in the file where it says:
# Comment or remove the line below.

If you see errors like below refer to above.
ERROR: Please edit the example config file /etc/freshclam.conf.
ERROR: Please edit the example config file /etc/clamd.conf.
ERROR: Can't parse the config file /etc/clamd.conf

Saturday, October 16, 2010

Adding a Superuser Account to Linux

I have been testing a Linux Application and found it useful to create a second superuser account on the box besides the root account. Below are the list of commands that I used:

Check the current root account's user ID, group ID and group memberships:
    id root

Create account with superuser privileges (this is for CentOS 5.5):
    adduser -u 0 -o -g 0 -G 0,1,2,3,4,6,10 LOGIN
    passwd LOGIN

Verify change:
    id LOGIN
    less /etc/passwd
    less /etc/shadow
    less /etc/group

To change the account properties:
    usermod [options] LOGIN

To delete the account if you don't care about the home directory:
    userdel -r LOGIN

If you chose not to delete the home directory and need to go back and do it later:
    rm -rf /home/LOGIN

A better way of doing this that aligns with best practice is to create a user and assign it to the wheel group and use 'sudo' instead:
    adduser -G 10 LOGIN
    Use 'visudo' to uncomment the below line:
# %wheel ALL=(ALL) ALL

Tuesday, August 10, 2010

Testing Website Encryption

Using Openssl, use the following commands to verify website encryption strength:

openssl s_client -no_tls1 -no_ssl3 -connect :443
openssl s_client -connect :443 -cipher NULL
openssl s_client -connect :443 -cipher LOW
openssl s_client -connect :443 -cipher MEDIUM
openssl s_client -connect :443 -cipher HIGH

The only command that should not generate an error is the last. If any other command returns results instead of an error, then the site's encryption strength is not sufficient.

Tuesday, July 20, 2010

Recursively Copy Only Files to New Location

Here is a simple command to copy only the files from directories. The downside is that it does not build out the direcotry structure, but that is not what I want to do right now, I just need the files:

Copy-Item -Path C:\Tools\tes*\*.exe -Destination C:\Scripts\test\ -Recurse

Wednesday, January 13, 2010

Install or Upgrade NMAP

With root privileges, run the following command-line:

sudo wget -c "" && bzip2 -cd nmap-5.21.tar.bz2 tar xvf - && cd nmap-5.21 && ./configure && make && sudo make install

Retrieved from

Tuesday, December 8, 2009

WMIC Command to start and stop a service

To restart a service on a remote computer from the command line:

wmic /node:"." service where name="MpsSvc" call StopService && wmic /node:"." service where name="MpsSvc" call StartService