list of free cyber security software free download

When searching for free cybersecurity software downloads, keep in mind that it's important to download software from reputable sources to ensure your computer's safety. Here are a few popular and trusted options for free cybersecurity software :

Avast Free Antivirus: Avast offers a free antivirus solution that provides basic protection against viruses and malware.

AVG AntiVirus Free: AVG is another well-known name in the antivirus industry, offering a free version with essential protection features.

Malwarebytes Free: Malwarebytes is a reliable anti-malware tool that can help detect and remove various types of malware.

Bitdefender Antivirus Free Edition: Bitdefender provides a lightweight and effective free antivirus solution.

ZoneAlarm Free Firewall: ZoneAlarm offers a free firewall that helps protect your computer from unauthorized access and threats.

Comodo Free Firewall: Comodo provides a free firewall that can help safeguard your computer against incoming threats.

OpenVAS: OpenVAS is an open-source vulnerability scanner that can help you identify security issues in your network.

Wireshark: Wireshark is a free and open-source packet analyzer that can be useful for network security analysis.

Nmap - A popular open-source network scanning tool used for network discovery and security auditing.

GnuPG (GPG) - A free encryption software that allows you to encrypt and decrypt your data.

KeePass - A password manager that helps you store and manage your passwords securely.

Crytoparty - A collection of free and open-source tools for encrypting emails, files, and more.

Spybot - Search & Destroy - A tool that scans for and removes malware, spyware, and adware.

AxCrypt - A file encryption software that lets you secure your sensitive files.

Remember to always download software from the official websites of the providers or from reputable sources like CNET, FileHippo, or the Microsoft Store to ensure that you're getting the genuine and safe software. Additionally, keep your cybersecurity software updated to ensure the best protection against the latest threats.

Best Free Cybersecurity Software Tools for Small Business

Small businesses often need to run lean to maintain their profit margins and the capital they need to expand and adjust. Sometimes, however, this results in sacrificing strong security systems for free offerings that may not fully meet their needs. In some instances, the cybersecurity tools smaller businesses use are the same ones that are designed for individual users.

There is a better way. Regardless of the size of your business, you can get the tools you need to safeguard your digital assets. What follows is your small business cybersecurity best practice guide. Read on to find cybersecurity tips for small businesses and some of the specific SMB cybersecurity tools you can use to tighten your

defenses against hackers and breaches. [source : Fortinet.com]

Free  Antivirus Software for cybersecurity 

ClamAV

ClamAV® is an open-source antivirus engine for detecting trojans, viruses, malware & other malicious threats. Clam AntiVirus (ClamAV) is a free software, cross-platform antimalware toolkit able to detect many types of malware, including viruses. It was developed for Unix and has third party versions available for AIX, BSD, HP-UX, Linux, macOS, OpenVMS, OSF (Tru64) and Solaris. As of version 0.97.5, ClamAV builds and runs on Microsoft Windows. Both ClamAV and its updates are made available free of charge. One of its main uses is on mail servers as a server-side email virus scanner.Free Download ClamAV here

Sourcefire, developer of intrusion detection products and the owner of Snort, announced on 17 August 2007 that it had acquired the trademarks and copyrights to ClamAV from five key developers. Upon joining Sourcefire, the ClamAV team joined the Sourcefire Vulnerability Research Team (VRT). In turn, Cisco acquired 

Sourcefire in 2013. The Sourcefire VRT became Cisco Talos,and ClamAV development remains there.

Developer(s) : Cisco Systems

Stable release : 1.1.0/ 1 May 2023

Repository : github.com/Cisco-Talos/clamav-devel Edit this at Wikidata

Written in : C, C++

Operating system: Unix, AIX, BSD, HP-UX, Linux, macOS, OpenVMS, Tru64 UNIX, Windows

Type : Antivirus software

License : GPL-2.0-only

Website : www.clamav.net

[source: wikipedia.org , clamav.net]

ClamWin

ClamWin Free Antivirus is a free and open-source antivirus tool for Windows. It provides a graphical user interface to the Clam AntiVirus engine.

ClamWin is a Free Antivirus program for Microsoft Windows 10 / 8 / 7 / Vista / XP / Me / 2000 / 98 and Windows Server 2012, 2008 and 2003.

ClamWin Free Antivirus is used by more than 600,000 users worldwide on a daily basis. It comes with an easy installer and open source code. You may download and use it absolutely free of charge. It features:

** High detection rates for viruses and spyware;

** Scanning Scheduler;

** Automatic downloads of regularly updated Virus Database.

Standalone virus scanner and right-click menu integration to Microsoft Windows Explorer;

Addin to Microsoft Outlook to remove virus-infected attachments automatically.

The latest version of Clamwin Free Antivirus is 0.103.2.1

Please note that ClamWin Free Antivirus does not include an on-access real-time scanner. You need to manually scan a file in order to detect a virus or spyware.

ClamWin Free Antivirus is based on ClamAV engine and uses GNU General Public License by the Free Software Foundation, and is free (as in freedom) software. To find out more about GNU GPL, please visit the following link: Philosophy of the GNU Project - Free Software Foundation.

ClamWin Free Antivirus uses ClamAV Scanning Engine

ClamAntivirusHomePage

ClamWin running on Windows 7

Developer(s)    :ClamWin Pty Ltd

Stable release  : 0.103.2.1 / June 7, 2021; 22 months ago

Repository  : github.com/clamwin/clamwin/ 

Written in  : C++ and Python

Operating system : Windows 98 and newer

Type             : Antivirus software

License             : GPL-2.0-or-later

Website               : clamwin.com 

Lynis

Lynis is an extensible security audit tool for computer systems running Linux, FreeBSD, macOS, OpenBSD, Solaris, and other Unix derivatives. It assists system administrators and security professionals with scanning a system and its security defenses, with the final goal being system hardening. [source : wikipedia.org]

Original author(s) : Michael Boelen

Developer(s) : CISOfy

Stable release : 3.0.8 / 17 May 2022; 11 months ago[1]

Repository : github.com/CISOfy/lynis 

Written in : Shell script

Operating system : FreeBSD, Linux, macOS, OpenBSD, Solaris

Type : Security Software, Audit tool

License : GNU GPLv3

Website : cisofy.com/lynis/

Free Download of Lynis

[source : wikipedia.org]

Lynis, an introduction Auditing, system hardening, compliance testing. Lynis is a battle-tested security tool for systems running Linux, macOS, or Unix-based operating system. It performs an extensive health scan of your  systems to support system hardening and compliance testing. The project is open source software with the GPL license and available since 2007.

 Typical use cases for Lynis include:

** Security auditing

** Compliance testing (e.g. PCI, HIPAA, SOx)

** Penetration testing

** Vulnerability detection

** System hardening

Who is use Lynis ?

Developers: Test that Docker image, or improve the hardening of your deployed web application.

System administrators: Run daily health scans to discover new weaknesses.

IT auditors: Show colleagues or clients what can be done to improve security.

Penetration testers: Discover security weaknesses on systems of your clients, that may eventually result in system compromise.

Supported operating systems

Lynis runs on almost all UNIX-based systems and versions, including:

*AIX

*FreeBSD

*HP-UX

*Linux

*macOS

*NetBSD

*NixOS

*OpenBSD

*Solaris and others

It even runs on systems like the Raspberry Pi, IoT devices, and QNAP storage devices.

[source : Lynis.net]

Free Software Data Loss Prevention for Cybersecurity 

MyDLP is a data loss prevention solution originally available released as free and open source software. Supported data inspection channels include web, mail, instant messaging, file transfer to removable storage devices and printers. The MyDLP development project originally made its source code available under the terms of the GNU General Public License.

MyDLP was one of the first free software projects for data loss prevention, but was acquired by the Comodo Group in May 2014. Comodo has since begun marketing the Enterprise version through its Comodo Security Solutions subsidiary, while the free version has been removed from the website. The open source code has not been updated since early 2014. [source :wikipedia.org]

Initial release    : Nov 16, 2009

Repository   : github.com/mydlp

Written in   : Erlang, Java, C++, C#, Adobe Flex

Available in   : English

Type           : Data Loss Prevention

License           : GNU General Public License

Website           : mydlp.com

Try MyDLP  for Free 

Learn 741 op-amp circuits basic with example

Transconductance Amplifier 

This circuit is a voltage-to-current converter . Here's how it permits an input voltage to control the brightness

of an LED

R3 controls Vin , Vary R3 to alter Iout, hence the brightness of the LED.

Transimpedance Amplifier 

Example : If R1 = 1000 Ohms then Gain = -1000

This circuit is a current -to-voltage converter. Here's how it transforms the current generated by a solar cell into an output voltage :

.

This circuit can amplify the signal from non-current generators like thermistors and photoresistors. connect one side of device to +9V and the other to pin 2 , ground pin 3. 

Op Amp IC 741 Basics, Characteristics, Pins, Applications

The 741 is a highly popular general purpose OP-AMP. It is simple to use , reliable, and inexpensive, it is used in most circuits.

IC OP-AMP 741

741 PINS

IC 741 Pin Out

Maximum Ratings

Supply Voltage                         +/-18 Volt

Power Dissipation                      500 mW

Differential Input Voltage        +/-30 Volt

Input Voltage (note)                 +/- 15 Volt

Output Short Circuit Time       Indefinite

Operating Temperature            0 Celcius to 70 Celcius Degree

Note : Input Voltage should not exceed supply voltage when supply voltage is less than +/- 15 Volts

741 Applications Circuit

Basic Inverting Amplifier Design 

Basic Inverting Amplifier

Example : if R1 = 1000 Ohms and R2 = 10000 Ohms, then Gain is -(10000/1000) or -10.

This is one of the most common OP-AMP circuits. For A Non-Inverted output use the amplifier on the facing page.

example the application of basic inverting amplifier is Unity-Gain Inverter Circuit :

This circuit use as a buffer or to convert -Vout to +Vout

Non-Inverting Amplifier Design

Non-Inverting Amplifier

Example: If R1 = 1000 Ohms and R2=10000 Ohms, then Gain is 1 + (10000/1000) or 11

Note that Vout is an Amplified but not inverted version of Vin.

Example of Non-Inverting Amplifier application is Unity-Gain Follower circuit.

Use to buffer signal from another circuit

Quad Beam Loop Antenna Calculator

Cubical Quad Beam Loop Antenna is fullwave length Antenna, designed in the mid of 1940's , each side being a quarter wavelength, and fed at a current loop in the center of one side, the voltage loops occur in the middle of the adjacent sides — and that reduces or eliminates the arcing. 

The background for the creation of the Cubic Quad Beam Antenna is due to the existence of shortwave radio stations located in the highlands. previously used a Yagi 

antenna which is more suitable for lowland, to transmit worldwide with high voltage input, This antenna is fed in the middle of the current loop, so the end is the 

high voltage loop. In the thin air of Quito, Ecuador,the high voltage at the tip causes a corona arc, and that arc periodically destroys the tip of the Yagi element. 

so Design station engineer Clarence Moore designed Cubical Quad Beam antenna to solve this problem.

Fig 1. Quad Loop Antenna

Fig 2. Quad Loop Antenna

The antenna shown in Fig. 1  is actually a quad loop rather than a cubical quad. Two or more quad loops, only one of which needs to be fed by the coax, are used to make a cubical quad antenna. If only this one element is used, then the antenna will have a figure-8 azimuthal radiation pattern (similar to a dipole). The quad loop antenna is preferred by many people over a dipole for two reasons. First, the quad loop has a smaller "footprint" because it is only a quarter-wavelength on each side Fig 1. Second, the loop form makes it somewhat less susceptible to local electromagnetic interference (EMI).

The quad loop antenna (and the elements of a cubical quad beam) is mounted to spreaders connected to a square gusset plate. At one time, carpets were wrapped around

 bamboo stalks, and those could be used for quad antennas. Those days are gone, however, and today it is necessary to buy fiberglass quad spreaders. A number of kits are advertised in the web.

The details for the gusset plate are shown in Fig.2 . The gusset plate is made of a strong insulating material such as fiberglass or in marine-grade plywood. 

It is mounted to a support mast using two or three large U bolts (stainless steel to pre- vent corrosion). The spreaders are mounted to the gusset plate using somewhat smaller U bolts (again, use stainless steel U bolts to prevent corrosion damage) 

Cubical Quad Beam Loop Antenna

The elements can be fed in the center of a horizontal side fig A, in the center of a vertical side fig B , or at the corner  fig C

There is a running controversy regarding how the antenna compares with other beam antennas, particularly the Yagi. Some experts claim that the cubical quad has a gain

 of about 1.5 to 2 dB higher than a Yagi (with a comparable boom length be- tween the two elements) . In addition, some experts claim that the quad has a lower angle of radiation. Most experts agree that the quad seems to work better at low heights above the earth's surface, but the differencdisappears at heights greater than a half-wavelength.

The quad can be used as either a single-element antenna or in the form of a beam. Figure Fig 3. shows a pair of elements spaced 0.13 to 0.22 wavelengths apart. One element is the driven element, and it is connected to the coaxial-cable feedline directly. The other element is a reflector, so it is a bit longer than the driven element. A tuning stub is used to adjust the reflector loop to resonance.

Because the wire is arranged into a square loop, one wavelength long, the actual length varies from the naturally resonant length by about 3 percent. The driven element is about 3 percent longer than the natural resonant point. The overall lengths of the wire elements are :

1. Driven element : L = 1005/F [MHZ] ft 

2. Reflector            : L = 1030/F [MHZ] ft 

3. Director              : L = 975/F [MHZ] ft 

with Shortwave Frequency range : 3 - 30 MHz, Center Frequency F[MHZ]  = 16.5 MHZ.

Input Center Frequency (in MHz) for Quad Beam Loop Antenna

Quad Beam Loop Antenna Calculator
Input Center Frequency
Driven Element in ft
Reflector in ft
Director in ft

One method for the construction of the quad beam antenna is shown in Fig. 4. This particular scheme uses a 12 x 12-in wooden plate at the center, bamboo (or fiberglass) spreaders, and a wooden (or metal) boom. The construc- tion must be heavy-duty in order to survive wind loads. For this reason, it is probbly a better solution to buy a quad kit consisting of the spreaders and the center structural element.