Μηνιαία αρχεία: Μάρτιος 2023


You have been pwned!

By clicking on the link you received and landing on our webpage, we were able to successfully attack your device and implant a virus. This virus will now spread throughout your entire system, infecting all of your files and documents. It will also allow us to remotely control your device and monitor all of your online activity. We will use this information to our advantage, and there is nothing you can do to stop us. Remember, anything is possible with the right tools and knowledge when it comes to hacking and cyberattacks. So always be cautious and protect your online security.

By clicking on the link you received and landing on our webpage, we were able to successfully attack your device and implant a virus. We have now gained access to all of your sensitive data, including personal information, financial records, and confidential documents. We will use this information to our advantage, and there is nothing you can do about it. Thanks for playing!

On a more serious note:

As part of our security awareness training program, we want to simulate a potential cyber attack scenario. By clicking on the link you received, you have been redirected to a landing page that would have potentially caused harm to your device if it were a real attack. This is an example of how hackers can use deceptive tactics to gain access to your device and implant a virus. By being vigilant and cautious when receiving unexpected emails or messages, you can help prevent such attacks.


5 packages can be upgraded. Run ‘apt list –upgradable’ to see them.

Updating an operating system is a critical task that ensures the system’s security, stability, and performance. In Ubuntu, updating the system involves running several commands in the terminal. In this technical post, we will explain the process of updating an Ubuntu Server installation and how to fix the issue of pending package upgrades.

The first command that needs to be executed is sudo apt update. This command updates the list of available packages from the Ubuntu repositories. The -y option instructs the system to answer “yes” to prompts, ensuring the process runs uninterrupted.

The second command is sudo apt upgrade. This command upgrades all installed packages to their latest versions. Again, the -y option is used to answer “yes” to any prompts.

The third command, sudo apt autoremove, removes any unnecessary dependencies that are no longer required by the system.

After executing these three commands, the system displayed a warning message that says that five packages can be upgraded. To see the list of upgradable packages, we needed to execute the command apt list --upgradable. This command lists all the upgradable packages along with their versions.

The following command we executed was sudo apt-get dist-upgrade. This command upgrades the system to the latest distribution release, including kernel upgrades. However, the command failed to upgrade the pending packages in this case.

To fix the issue, we executed the command sudo apt-get install --only-upgrade $PACKAGE for each pending package. This command upgrades the specified package to its latest version. The $PACKAGE variable should be replaced with the package name that needs to be upgraded.

In summary, updating an Ubuntu Server installation involves running the sudo apt update, sudo apt upgrade, and sudo apt autoremove commands in the terminal. If there are any pending package upgrades, we can use the apt list --upgradable command to see the list of upgradable packages. If the sudo apt-get dist-upgrade command fails to upgrade the pending packages, we can use the sudo apt-get install --only-upgrade $PACKAGE command to upgrade each package individually.


ffmpeg to convert MP4 files to MKV files with the libx265 video codec

When working with video files, there are times when you need to convert them from one format to another or modify them in some other way. One of the most popular tools for this is ffmpeg. This command-line tool can do a lot of things related to video processing, including conversion, resizing, cropping, and more. In this blog post, we will explain a script that uses ffmpeg to convert MP4 files to MKV files with the libx265 video codec.

The Script:

Here’s the script that we will be explaining:

for FILE in *.mp4; do
  echo -e "Processing video '\e[32m$FILE\e[0m'";
  ffmpeg -i "${FILE}" -analyzeduration 2147483647 -probesize 2147483647 -c:v libx265 -an -x265-params crf=0 "${FILE%.mp4}.mkv";
done;

Let’s break this script down line by line to understand what it does.

for FILE in *.mp4; do
...
done;

This line starts a loop that goes through all the files in the current directory that have the “.mp4” extension. The loop will execute the commands inside the “do” and “done” keywords for each file that matches this pattern.

echo -e "Processing video '\e[32m$FILE\e[0m'";

This line uses the “echo” command to print a message to the console. The message includes the file’s name being processed, which is stored in the $FILE variable. The “\e[32m” and “\e[0m” are escape sequences that change the color of the text to green. This is just a way to make the message more visually appealing.

ffmpeg -i "${FILE}" -analyzeduration 2147483647 -probesize 2147483647 -c:v libx265 -an -x265-params crf=0 "${FILE%.mp4}.mkv";

This line runs the ffmpeg command to convert the current file from MP4 to MKV format using the libx265 video codec. Let’s break down each of the options:

  • “-i ${FILE}” specifies the input file. “${FILE}” is the name of the file being processed, which is stored in the $FILE variable.
  • “-analyzeduration 2147483647” and “-probesize 2147483647” are options that tell ffmpeg to analyze the entire file before starting the conversion process. This can help avoid some issues that can occur when processing large files.
  • “-c:v libx265” specifies the video codec for the output file. libx265 is a popular video codec that provides good quality at a smaller file size.
  • “-an” specifies that there should be no audio in the output file.
  • “-x265-params crf=0” sets the quality level for the video. A value of 0 means lossless compression, which is the highest quality possible.
  • “${FILE%.mp4}.mkv” specifies the name of the output file. “${FILE%.mp4}” removes the “.mp4” extension from the input file name, and “.mkv” adds the “.mkv” extension to the end.

Conclusion:

The script we’ve just explained is a simple example of how you can use ffmpeg to convert MP4 files to MKV files with the libx265 video codec. It uses a loop to process all the files in the current directory that match the “.mp4” pattern. The script also prints a message to the console for each file


Using nmap to scan a network and identify which hosts are alive

The command “nmap -sP 192.168.100.0/24” scans a network and identifies which hosts are alive (i.e., which IP addresses are being used) within the specified range.

In more detail, the “nmap” command is a widely used network exploration tool that can be used for tasks such as host discovery, port scanning, and service enumeration.

The “-sP” option tells nmap to perform a “ping scan,” where it sends an ICMP echo request to each host in the specified IP range and checks for responses. This method is typically faster than other scanning techniques because it only determines whether a host is up or not without gathering additional information about the host’s ports or services.

The “192.168.100.0/24” argument specifies the IP range to be scanned, specifically the subnet mask “255.255.255.0,” which corresponds to the range of IP addresses from 192.168.100.0 to 192.168.100.255. The “/24” suffix is a shorthand notation for the subnet mask.

Overall, the command “nmap -sP 192.168.100.0/24” is a helpful tool for network administrators or security professionals who need to identify which hosts are active on a particular network quickly. It can help to identify potential security vulnerabilities or unauthorized devices connected to the network.