Malware is a broad term used to describe an intentionally malicious program intended to harm or otherwise negatively affect the user, their computer, others’ computers, or their files. This can range from stealing personal info such as account details and credit card information, to displaying unwanted ads, to preventing access to your files, all depending on the type of malware in question. The type also plays a major factor in how it spreads, both to your computer and across the internet, however, the main source of malware is files downloaded and run either by the user or a malicious website. Once a computer is infected, these programs tend to spread to other devices connected to said computer, either through wireless connections, such as wifi and bluetooth, or physical connections.
Malware, as mentioned previously, can be classified using several different categories, distinguishing different kinds of malware based on their effect on the host system or how they infect and spread to people’s computers. One of the most common types of malware you’ll encounter is a Trojan, which is a piece of malware that pretends to be another program or file. The program uses this to trick the user into running it, often in a way that gives it control over vital parts of your computer, where it then runs its malicious code. Another type of malware is a Worm, which spreads by replicating itself across devices sharing a network connection, such as being connected to the same wifi network. After infecting one device, it will scan for other devices connected to the same network, replicating itself on to any other vulnerable device it finds. Computer Viruses, in contrast, are a type of malware that replicates by inserting itself into other programs on your computer, which then run the virus’s code before its own. Both Viruses and worms spread by replication, however, viruses usually require a host program to run, while worms are stand-alone, they don’t require another program to run. Once the malware has spread to other systems, it begins to affect the host system, such as with Ransomware, which essentially locks you out of the files on your computer, requiring you to pay whoever the ransomware belongs to in order to access your files. These typically give you a deadline to pay them by to get your files back to pressure you into paying them and to prevent you from seeking someone to recover your files without paying. Spyware, conversely, tries to remain as hidden as possible from the user, as its goal is to covertly collect your private information and relay it to its creator. This can include recording inputs you make on your keyboard in order to steal account details and credit cards, searching through your files and browser storage for passwords, or recording your screen.
You now know what each type of malware does, so you can understand the importance of knowing whether the file or program you’re downloading is, or is not, malware. This can be fairly simple to check, as long as you know the signs. Firstly, it is always a good idea to scan the program with your system’s antivirus before running it, such as with Windows Defender on Windows, as this will catch most forms of malware. Next, make sure the file extension, the section of the file name after and including the period at the end of the name, matches what you’re expecting this type of file to have, such as a ‘.mp3’ for music or ‘.txt’ and ‘.doc(x)’ for text documents. Some common file extensions of malware include ‘.exe’, ‘.dll’, ‘.vbs’, or ‘.zip’, in addition, some malware attempts to mask these extensions by including the expected file extension before it to further trick you, such as ‘song-3.mp3.exe’. Another good way to identify malware is by looking at the size of the file, as malicious files tend to be bigger than the file their masquerading as, you can check this by right clicking the file you’re checking and clicking the ‘properties’ option. Furthermore, make sure the person you’re getting the file from is both trustworthy and real; don’t download files from websites you don’t trust and make sure whoever you’re downloading from is who they say they are. Finally, the safest way to check for malware is checking the permissions the file is asking for. Specifically, asking for any permission that doesn’t fit is a good sign, particularly if it asks you to run it as an administrator.
The quiz below will test you on the malware knowledge you've gained.