How antivirus software recognizes a cyber threat and how it works

THE’antivirus it is one of the main tools to protect our electronic devices from cyber attacks and detect any malware such as worms, trojans and spyware. This type of software deals with scanning the computer for any harmful files, which could damage the system. An antivirus is mainly based on three fundamental mechanisms to identify malware: the signature-based detectionThe heuristic detection and that behavioral. Let’s analyze them in detail, so as to understand how does an antivirus recognize a cyber threat.

How Antivirus Works: Three Ways to Detect Cyber ​​Threats

The signature-based detection it is one of the oldest methods used in cybersecurity and consists of compare the device files with a database of already known viruses. Each malicious program has a unique “signature”, which is a set of identifiable characteristics in its code. When antivirus software finds a match, it reports the file as malicious. As effective as this method may be, it has its limitations as it only works with threats already known and cannot identify new malicious software that has not yet been added to the antivirus database.

To overcome this limitation, many antiviruses use the heuristic detectionwhich does not look for exact correspondences, but rather looks for possible critical issues that arouse a certain suspicion in the analyzed software. This detection technique can occur in several ways. In some cases, the source code of the software is analyzed and compared to known viruses: if a certain match is found with known viruses present in the heuristic database, the code is flagged as a potential threat. This approach helps detect new variants of computer viruses that may escape signature-based detection. This, however, can also lead to a greater risk of encounter false positivesi.e. incorrectly reporting harmless files as threats. In this regard, what happened in 2011 with the browser is emblematic Google Chromewhich was incorrectly classified as dangerous by the antivirus Windows Defender (also known as Microsoft Defender Antivirus AndSecurity Essentials).

Another method used by antivirus software is Behavior-based detectionwhich observes the activity of a program as it is actually executed. If the program shows suspicious actions, like attempts to infect other files or connect to remote serversthe antivirus may report it as dangerous.

How virus scanning works

The scanning process of an antivirus usually starts with a full system scanwhich analyzes each file to identify potential threats. After that, most antivirus software runs regular automatic scans at scheduled intervals or manual scanswhich the user can activate on the spot, whenever he prefers. Scanning can be quick (happens in a maximum time of 30 minutes), focusing only on critical areas such as the computer’s memory, the operating system directory and temporary files, or it can be more thorough (like the one that happens when you use the antivirus for the first time), in which every single file (including those on USB sticks and other external media) is carefully examined.

In addition to having regular scans, it is important enable automatic virus definition updates. These updates are essential to ensure that your antivirus can recognize even the latest threats.

The moment an antivirus detects a threat, it will try to remove it from the system. If it fails to do so, it may adopt some ad hoc security measures. Among these is the so-called forty which, as can easily be understood from its name, consists of isolating suspicious files in a safe area of ​​the system, so as to prevent it from being damaged.

he use of antiviruses is not enough to protect us from malware

Despite the effectiveness of antiviruses, it is important to highlight that no software can guarantee total protection against all cyber threats. This is because these they are constantly evolving and I am increasingly widespread: according to some estimates, from 2009 to 2019, malware infections went from 12 million to over 812 million, with a increase of 6,500%.

This is why, in addition to relying on a good antivirus, we suggest you adopt a multi-layered security strategywhich includes practices such as using strong passwords, regularly updating software and adopting tools such as VPNs to protect sensitive information when online.