Issues related to what kind of computer viruses are and their names, what are the ways of their penetration into the system and the impact on computers or user data, ordinary users usually do not care at all until a certain point. But when the operating system or the programs installed in it begin to behave completely inappropriately, many begin to look for answers, but it is often too late. But there are many cases where the OS (most often it relates to Windows-systems) is not something that does not work correctly, but it can even be blocked or completely fail. Let's try to figure out what kind of computer viruses are. The names of the main threats will also be given, however, it should be said right away that the classification presented below is purely conditional, since today there is no unified structured system for recognizing computer threats and classifying them as a specific class. And this is mainly due only to the fact that more and more often there are mixed types of threats that it is simply impossible to include in a particular class.
The simplest classification of computer threats
So, for starters, consider the simplest division of threats into main types. It is believed that at the moment the main ones are viruses and worms.
The difference between these two large categories is that the former infiltrate computers through malicious files and inject their own codes into programs, and the latter can infect files of a strictly defined type (for example, all EXE-format objects, office documents or multimedia content). Such a separation does not allow us to clearly understand the complete difference between some types of threats, therefore, for more detailed classification, additional features are used, which will be discussed below.
Ways to introduce threats to computers
But let's leave the names of computer viruses aside for now, and pay special attention to figuring out exactly how threats can penetrate user computers. Most often, experts identify several key loopholes here:
- vulnerability of the operating system and browsers used for web surfing;
- removable media;
- Networks
- inadequate quality of antivirus software;
- stupidity or negligence of the user himself.
Regarding operating systems, it is naive to believe that viruses only affect legacy DOS systems or Windows. Until recently, it was believed that virus threats did not work in the environment of "apple" and UNIX-like OS, including Linux. However, now an absolutely confirmed fact is the impact of viruses and malicious codes with the disabling of the same “iPhones” running on iOS, or Android devices whose operating systems are based on the Linux kernel.
With browsers, I think, and so everything is clear, since when visiting untrustworthy resources that may contain threats, using the same Internet Explorer, viruses can be typed quite simply, not only when downloading some files, but just logging in A site that can automatically execute ActiveX scripts.
The quality of antiviruses can also play a trick on the user, as some widely advertised and praised antiviruses are unable to fully protect the computer and user information from threats. In this case, viral applets, many of which even have security certificates, can be called a vivid example.
On removable media, threats are most often present in the form of autorun files (Autorun.inf), and when connected to a PC or laptop, computer viruses infect the device precisely when it is triggered.
As for the carelessness of users, this most often manifests itself when installing programs downloaded from questionable sources (for example, from torrent trackers), when they do not pay attention to proposals for installing related supposedly affiliate software, which actually turns out to be an adware or spyware virus type. Well, we are not talking about ignoring antivirus warnings that may appear when trying to switch to virus-containing sites on the Internet.
In addition, when combining computers on a network, threats can be transmitted from one infected terminal to all the others through gaps in a network that does not have an antivirus or firewall.
Signs of a computer system infection
Due to the effect, which may not be immediately apparent, system braking begins with an unreasonably high load on system resources (CPU, RAM or hard disk).
Sometimes installed applications stop working, or driver errors occur, which can lead to the appearance of the notorious blue screens. Finally, the browser may be flooded with ads, but, sadly, sometimes some files turn out to be locked or encrypted, the operating system stops loading, and in this case only full disk formatting with reinstalling the OS helps.
Computer viruses: types and their names in the main classes
Now move on to a more advanced classification. The main computer viruses in the general case are as follows:
- file viruses contained in an infected file and activated only when it is launched by the user himself or when the system / program accesses it;
- boot viruses that embed their own codes or startup commands in the autostart system or removable media;
- macro viruses contained on websites on the Internet or sent by e-mail in the form of scripts that run exclusively in installed programs or add-ons;
- network viruses.
Again, this distribution can also be called conditional, since today there are also mixed types of threats like file-boot or network macro viruses.
The main types of computer viruses: names and description of exposure
Finally, the most accurate description of threats can be found in the following classification:
- Trojan applications that penetrate computers under the guise of safe legal software that can gain access to installed programs and user data, transfer computer control or “leak” information to cybercriminals;
- spyware stealing sensitive sensitive information or tracking user actions on a computer;
- Keyloggers related to spyware that monitor keyboard input
- ransomware (winlockers) blocking the system and requiring a transfer of money for unlocking;
- encryptors that fully encrypt user or system files of a certain type;
- vandals seeking to cause the operating system maximum damage in terms of loss of performance;
- hybrid rootkits that simultaneously track user actions and interfere with the system’s operation according to a specific scenario;
- botnets that turn a computer into a kind of zombie and use its resources to carry out DDoS attacks or impact on other terminals via networks or the Internet.
In general, it is worth saying that these are only the main names of computer viruses, since they are replenished almost daily with more and more new copies that cannot be attributed to any of the known categories.
Functioning Algorithms
Computer viruses and their types have been sorted out a bit. However, we should separately dwell on the classification of threats in terms of the algorithms used by them. For this, a division into resident and non-resident viruses is accepted.
Resident threats are programs that load their executable components directly into RAM and can be constantly active from the moment the operating system boots up until the computer shuts down. Non-resident threats usually have a limited duration of activity, although they can also load their small resident part into RAM, but usually this does not happen.
A vivid example of residents is all kinds of macro viruses in the form of executable scripts, and many of them also use stealth technology, which allows them to remain unnoticed in the system, replacing the elements accessed by the operating system with their own processes.
Another distribution of computer virus names by classes is related to self-encryption and polymorphism. Encryption in a sense resembles stealth disguise, but polymorphic viruses can constantly change, which is very difficult to determine by protective means.
Some of these threats may not contain signatures of malicious codes at all, according to which it would be possible to classify them as viruses at least with some degree of probability. But the most dangerous threats very often use even some non-standard disguise methods that allow them to hide deep in the kernel of the operating system, where no antivirus can get.
Destructive properties of viruses
Despite their names, computer viruses of different classes are very similar to each other. But in order to classify them according to the degree of impact, it is customary to distinguish four categories:
- harmless (joke programs);
- non-hazardous (limited only by the consumption of system resources);
- Dangerous (leading to very serious malfunctions in the OS);
- very dangerous (completely disabling the system or destroying data stored on the computer).
The main methods of dealing with computer threats
Naturally, it is recommended to use standard antiviruses that have signature and behavioral analysis modules, as well as Anti-Stealth modules, as the first method for detecting all kinds of known threats or initializing suspicious objects.
Antiviruses also look good in this regard, with the ability to send suspicious objects for analysis to the "cloud" or to the "sandbox". But you cannot absolutely rely solely on such tools.
Tips for self-removing some adware viruses
Adware viruses, which have recently been divorced by so many, can be removed by yourself. As a rule, such threats are not especially masked in the system, and you can find them either in the list of installed programs, or among panels or browser extensions.
To neutralize these threats, it is enough to remove the main application, clean the registry and residual files in the "Explorer", change the search engine and the start page in browsers, and then finally correct the path to the executable file for launching the browser in the shortcut properties, removing all unnecessary links and postscripts after specifying its names with the extension. Not bad in terms of removal, uninstaller programs that automatically clean up the leftovers help.
Summary
That’s briefly all that concerns the names of computer viruses, their distribution by classes, groups and categories, based on different criteria. As additional recommendations, you can advise the following:
- install only powerful antiviruses, even shareware (many of these programs can be permanently activated for 30 days or more using special freely distributed codes);
- Do not ignore antivirus warnings when using the Internet;
- Do not visit obviously doubtful sites and do not download files from them;
- carefully consider the suggestions for installing additional software;
- check the contents of removable media before performing any action with them;
- Perform preventive checks at least once a month using portable utilities.