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Ubuntu Antivirus

What is Antivirus?

Anti-virus software is also called anti-malware. It is a computer program used for preventing, detecting, and removing malware. Originally, anti-virus software was developed for detecting and removing computer viruses so the name. Although, antivirus software began for protecting from many threats of computer with the other malware proliferation.

In particular, the latest anti-virus software can defend users from spyware, adware, fraud tools, dialers, malicious LSPs, worms, trojan horses, rootkits, backdoors, keyloggers, ransomware, browser highjackers, and mischievous browser helper objects.

Also, some products include protection from several computer threats like malicious and infected botnet DDoS attacks, APT (advanced persistent threat), social engineering techniques, online banking attacks, online identity, fishing and scam attacks, spam, and malicious URLs.

Anti-virus identification methods

Some solid theoretical outcome in the computer virus study is Fredrick B. He said that no algorithm can find every possible virus perfectly. However, by applying distinct defense layers, a good rate of detection might be achieved.

There are many techniques that antivirus engines can apply for identifying malware:

Ubuntu Antivirus
  • Data mining methods: It is one of the latest methods used in malware detection. Machine learning and data mining algorithms are used for trying to divide the behavior of the files (as either benign or malicious) given a file feature series that are derived using the file itself.
  • Sandbox detection: It is a specific behavioral-based detection method that, rather than finding the behavioral fingerprint during the run time, runs the program within a virtual environment, logging what operations the program implements.

The anti-virus engine can decide if the program is mischievous or not relying on the operation logged. If not, the program is run within the real environment. This method has shown to be quite impressive, given its slowness and heaviness, it's rarely applied in several solutions of the end-user antivirus.

Signature-based detection

Classical anti-virus software heavily depends upon signatures for identifying malware.

When a sample of malware substantially comes into the antivirus firm's hands, it is investigated by dynamic analysis systems or malware researchers. Then, a proper file signature is derived and included in the signature database of an anti-virus software once it is confirmed to be malware.

However, the signature-based method can effectively include malware outbreaks, many malware authors have attempted to stay ahead of a step of application by writing "polymorphic", "oligomorphic", and more newly "metamorphic" viruses, that encrypt segments of themselves or change themselves as a disguised method, to not the same virus signature within the dictionary.


Several viruses begin as one infection and from either refinements or mutation by other attackers, can develop into many slightly distinct strains, known as variants. Generic detection defines the detection and deletion of multiple threats with one virus definition.

For instance, the Vundo Trojan has many family members, relying on the anti-virus classification of the vendor. Symantec divides the Vundo family members into two different categories: Trojan.Vundo.B and Trojan.Vundo.

While it might be beneficial to detect a particular virus, it could be faster to find a virus family from a generic signature or an inexact match to a previous signature. The researchers of the virus detect common areas that every virus of a family uniquely shares and can establish one generic signature.

Often, these signatures include non-contiguous code with wildcard characters in which differences lie. The wildcards permit the scanner to find viruses even if they are protected with meaningless and extra code. A detection that applies this method is called "heuristic detection".

Rootkit detection

An antivirus application can attempt for scanning rootkits. The rootkits are a kind of malware established for gaining administrative-level control on a computer device without being found. Rootkits can modify how the OS functions and, in a few cases can tamper with an antivirus program and consider it ineffective. Also, rootkits are hard to remove, in a few cases needing a full re-installation of the OS.

Real-time protection

Auto-protect, resident shield, background guard, on-access scanning, real-time protection, and other synonyms define the automatic protection given by most anti-spyware, antivirus, and other anti-malware functions.

It monitors computer devices for malicious activities like adware, spyware, computer viruses, and other mischievous objects. Real-time protection finds threats in files and scans applications in real time because they are downloaded on the device.

Related Issues of Antivirus

Ubuntu Antivirus

Sudden renewal costs

A few commercial end-user license agreements of antivirus software contain a section that the subscription will automatically be renewed and the credit card of the purchaser billed automatically, during the renewal time without clear approval.

Rogue security software

A few apparent programs of antivirus are malware masquerading as genuine software like Mac Defender, MS Antivirus, and WinFixer.

Issues occurred by false positive

A "false alarm" or "false positive" is when an anti-virus application recognizes a non-mischievous file as malware. It can lead to some serious problems when it happens.

Some Serious false positive examples are listed and explained below:

  • May 2007: A false virus signature delivered by Symantec falsely removed necessary files of the operating system, leaving several PCs unable to start.
  • May 2007: An executable file needed by Pegasus Mail in Windows was mistakenly found by Norton AntiVirus as a Trojan and it was automatically deleted, avoiding Pegasus Mail from executing. Norton anti-virus had mistakenly recognized three Pegasus Mail releases as malware and would remove an installer file of Pegasus Mail when that happened.
  • April 2010: McAfee VirusScan found svchost.exe, a general binary of Windows as a virus on devices executing Windows XP along with Service Pack 3, leading to a reboot loop and casualty of every network access.
  • December 2010: A false update in the AVG antivirus suite destructed 64-bit Windows 7 versions, considering it unable to start, because of an endless boot loop established.
  • October 2011: MSE (Microsoft Security Essentials) deleted the web browser, i.e., Google Chrome, rival to the own Internet Explorer of Microsoft. MSE flagged Google Chrome as the Zbot banking trojan.
  • September 2012: An anti-virus suite of Sophos recognizes several update mechanisms, containing its own, as malware. Sophos anti-virus can consider itself unable to update, needed manual intervention for fixing the problem if it was constructed to automatically remove detected files.
  • September 2017: A Google Play Protect antivirus began recognizing the Moto G4 Bluetooth application of Motorola as malware, leading to Bluetooth functionality becoming disabled.

Interoperability and system-related issues

Running more than one antivirus program simultaneously can create conflicts and degrade performance. However, various companies (including Microsoft and G Data Software) have established applications that can execute more than one engine concurrently using a concept known as multiscanning.

Sometimes, it is essential to disable antivirus protection temporarily if installing big updates like updated graphics card drivers or Windows Service packs. Running antivirus protection may completely or partially prevent major update installation. Antivirus applications can lead to some problems at the installation time of an OS upgrade.


December 2007 studies represented that the effectiveness of an anti-virus application had diminished in the previous year, specifically against zero-day or unknown attacks. The c't computer magazine detected that detection rates for the attacks had decreased from 40-50% in 2006 to 20-30% in 2007. The only exception at that time was the NOD32 antivirus, which handled 68% of the detection rate.

The issue is magnified by the virus author's changing intent. It was obvious if a virus infection was available a few years ago. At that time, viruses were specified by amateurs and destructive pop-ups or behavior. Often, modern viruses are specified by professionals and financed by some criminal organizations.

New viruses

Anti-virus applications are not always efficient against fresh viruses, even those that applied non-signature-based techniques that should find fresh viruses. The cause for it is that the virus designers inspect their new viruses on the big antivirus software to make sure that they aren't found before publishing them into the wild.

A few new viruses, specifically ransomware, apply polymorphic code for avoiding disclosure by virus scanners. A virus, i.e., proof of concept had used the GPU (Graphics Processing Unit) for avoiding disclosure from antivirus applications. Its potential success involves bypassing the Central Processing Unit to make it much more solid for security researchers to evaluate the inner implementation of such malware.


Identifying rootkits is a big challenge for all anti-virus applications rootkits have complete administrative access to the system and are unseen to users and hidden from the running process lists in the task manager. Rootkits can change the inner implementations of the OS and interfere with antivirus applications.

Damaged files

An antivirus application will attempt to delete the virus code through the file at the time of disinfection, but it's not always able for restoring that file to an undamaged state if a file is infected by a system virus. Damaged files can be only restored from previous shadow and backup copies (it is also accurate for ransomware), installed software that's damaged needs reinstallation in such situations.

Firmware infections

In the computer, a writeable firmware could be infected by mischievous code. It is a major concern, as any infected BIOS can need the real BIOS chip to be substituted to make sure the mischievous code is removed completely. Antivirus application is not efficient at protecting motherboard BIOS and the firmware from infection.

Security researchers found that USB devices include writeable firmware that can be changed with mischievous code ("BadUSB") in 2014, which antivirus applications can't prevent or detect. The mischievous code can execute undetected on the system and can even infect the OS before booting up.

Antivirus applications for Ubuntu

Ubuntu Antivirus

Comodo Antivirus

Comodo antivirus is also known as CAVL (Comodo Antivirus for Linux) provides similar virus protection as Windows software along with extra features of a completely anti-spam configured system.

Features of Comodo

  • Dedicated AV protection catches every known threat
  • Includes custom scan profiles, detailed event viewer, and scan scheduler
  • Automatic updates for updated virus protection
  • Mail filter is suitable for Exim MTA's, Sendmail, Qmail, and Postfix
  • Download and forget. No disturbing false alarms, only virus protection

ClamAV Antivirus

It is an open-source antivirus engine used in a range of situations including endpoint security, web scanning, and email scanning. It offers several utilities including a scalable and flexible multi-threaded daemon, an advanced tool for database updates automatically, and a command-line scanner.

Features of ClamAV

  • Milter interface
  • Command-line scanner
  • Integrated database updater along with support for digital signatures and scripted updates
  • Updated virus database more than one time/day
  • Built-in support for every classic mail file format
  • Built-in support for famous document formats including PDF, RTF, Flash, HTML, MacOffice, and MS Office files.

NOD32 Antivirus

Protect our workstation of Linux from threats designed for Linux and every cross-platform malware that can pass on to other Apple or Windows computers within the network. For Linux desktop, ESET NOD32 antivirus is a completely fledged solution of antivirus that plays a necessary role in protecting our online identity.

Features of NOD32

  • Proactive, strong protection: Finding viruses including fresh ones in actual time, with the help of heuristic analysis of the ThreatSense Scanning engine of the program.
  • Finds multi-platform threats: A solution of ESET for Linux desktop that stops every threat regardless of what OS they are targeting macOS, Linux, or Windows.
  • Low system footprint: Make sure that the system quickly boots and leads to no system slowdowns.
  • Basic operation with the on-screen graphical interface designed for Linux Desktop Environment.

Kaspersky Endpoint Security for Linux

It offers corporate networks executing Unix-based OSes on their end machines along with centralized protection from every kind of malware and possibly dangerous programs.

It comes from a product family that is based on a uniform set of the best anti-malware and other technologies, the innovative fresh antivirus engine of Kaspersky Lab applies the architecture of cutting-edge components for increasing its stability and performance, offering reliable protection that is easy to manage and control.

Features of Kaspersky

Ubuntu Antivirus
  • Antivirus engine: An application is based on a fully fresh antivirus engine that can dramatically increase the speed of system scanning, utilize the system resource uses and has a minimal clash with other systems.
  • Heuristic analyzer: Classical signature scanning is complemented to the enhanced heuristic analyzer. It helps to find unknown threads that are the same as those that have been already found and increases the overall protection level significantly.
  • Centralized administration: A variety of improvements has got the manageability of the application to a new level. The new Kaspersky Endpoint Security for Linux version is completely supported via Kaspersky Security Center. Kaspersky Security Center is a management tool that makes it convenient for completing a range of IT security management operations, beginning from remote distribution of the endpoint security applications to the production of system event reports.

F-PROT Antivirus

F-PROT antivirus establishes on the reliability history of the product, is easy to use, and provides a robust yet affordable solution of antivirus. For Linux workstations, F-PROT anti-virus is easy to use, efficient, and fast.

It can protect Linux workstations from the increasing worms, virus threats, and other malware by disinfecting and detecting or removing mischievous programs. Several unknown threats can be found with the heuristic technology of F-PROT, hence offering the strongest defense present and being the best solution for our desktops and laptops.

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