What is malware? The best 14 tips against malware

What is malware?

This article explains everything every computer user should know about malware.

… and how to get rid of it.

Let’s get started!

What is malware?

Malware is a computer program that has a deliberately negative effect on the computer and/or the computer user. The word is made up of malus (Latin for bad) and (soft)ware.

Poorly programmed software can have a negative effect on a computer (user) (crashes, corrupt files, memory errors). The developers have not intentionally caused this effect and the manufacturer attempts to rectify these gaps and malfunctions in the programme. These do not fall under the term malware.

Harmful functions of malware

How can “bad” software damage your computer? A distinction is made between virtual and physical errors. Virtual damage or impairment is, for example

• Deletion of documents and multimedia files
• Modification of documents and multimedia files
• Leakage of documents to blackmail you
• Making access more difficult (DDoS)
• Restricting access to files with a password (ransomware, see below)
• Computer does not start / does not respond / function is inactive
• Reduce system performance of the computer (cryptominers)

A physical error is e.g.

• Computer components overheating / burning down
• Overvoltages
• Switching off the fan (overheating) of the CPU
• Shortening hard disc life due to constant overwriting

Physical errors have become rare because the firmware (software for hardware) switches off the computer if the temperature is too high. Nevertheless, there is still malware that bypasses even these security mechanisms.

13 most important types with malicious functions

Viruses and Trojans make up 75 % of the malware on the Internet. In reality, we hardly have any pure forms of malware any more. Different types of malware often work together and take on individual tasks:

1. Viruses can only spread with the help of people. People unintentionally carry an infected USB stick from computer to computer, for example. Every computer to which the USB stick was connected is infected.
2. Trojans disguise themselves as useful software that carries out harmful activities in the background. This can be a payment programme or a free game.
3. Worms spread automatically. After hacking a computer, the worm uses the user’s email programme and sends messages with a copy of itself to all the user’s contacts.
4. Rootkits are difficult for antivirus programmes to detect and are just as difficult to remove because they embed themselves deep into the system (firmware level).
5. Spyware spies on you: browser history, microphone, camera, applications …
6. Keyloggers collect all passwords and data that you enter on the keyboard.
7. Govware or state trojaners monitor your computer activity (by governments).
8. Archive bombs unpack useless files that flood your computer with data that you can no longer save.
9. Droppers help other malware onto your computer. Droppers are invisible or are not recognised and download other malware.
10. Adware displays (annoying) adverts that are often not easy to remove. They do not “destroy” your computer or data, but are annoying to use.
11. Cryptominers use your system performance to earn money with bitcoins or altcoins.
12. Joke is a fake malware. The software has no malicious function.
13. Ransomware encrypts your files. The hackers demand money from you for decryption.

Strategies of malware criminals

Attack Vectors – malware attack vectors

Malware gets onto your computer in various ways:

• Email: The criminals send most of the malware via electronic mail. The malware data reaches the computer via an (encrypted) attachment or download link.
• USB stick / USB devices: The hackers load a plug-and-play file onto a harmless USB stick with your company logo. Once inserted into the computer, the computer is infected.
• Downloads: Want to watch the latest cinema film for free? The “Kino-Viewer.exe” is definitely genuine! After installation, the program does not show any films, but the software has cleaned your hard drive.
• Adverts : Can adverts be more than just annoying? Yes! The animated adverts work with a programming language that your computer executes(JavaScript). If you call up a website with adverts, you may already be infected.
• Security gap in software: My new computer with the latest software is secure against known malware … but not against the zero-day vulnerabilities. Criminals exploit “software manufacturing defects” to infiltrate your computer.

Targets of the criminals

What are the criminals‘ motives? Why do they distribute malware?

• Greed for money: In recent years, the number of so-called ransomware has risen sharply. Criminals encrypt all your files so that you have to buy the password from the criminals for a ransom. Hacking with malware is a very profitable business.
• Retaliation / activism: Criminals try to take revenge on other people, groups or organisations because they believe they have been treated unfairly, e.g. the hacker organisation Anonymous has paralysed websites of governments and authorities.
• Damage / obstruction: Organisations and governments pay hackers to hack their competitors (other companies or states). Criminals can switch off the electricity in your home.

Protection against malware

14 tips against malware

What is the best way to avoid a hack? Use the following strategies:

1. Known is better: Only use reputable websites for shopping, downloading and reading news. Don’t trust security seals such as e-Trusted-Shops and SSL / TSL across the board.
2. Computer protection: An antivirus programme is a must for every computer and offers you basic protection, but it is not enough
   
3. Common sense: There are no “free” downloads of multimedia and software that normally cost money. Either the program is a trial licence, a trailer or you have downloaded new malware onto your computer. The same goes for super bombastic deals.
4. Switch off annoying things: Use AdBlock software for your computer or use a PI HOLE to pre-filter internet traffic ⇾ complete guide.
5. Underestimated cloud advantage: Stop using third-party USB sticks! If you want to transfer files larger than 4 Megabyte, use a cloud exchange. The cloud providers scan the uploaded files for malware. When you download the file to your computer, the antivirus programme on your local computer checks the file again.
6. Security basics: Always install the latest programme and operating system updates promptly. Criminals have also developed malware for Linux and macOS. Protect yourself against known vulnerabilities by updating regularly.
7. Say NO by default: If a programme wants to make a change to the Windows firewall, always refuse (unless you are absolutely sure what you are doing).
8. Less is more: Uninstall all programmes that you don’t know or haven’t used for a long time (except Windows stuff). Any outdated software is a gateway for criminals.
9. Passwords: Use good passwords (12 characters with numbers, letters and symbols) – and only change your passwords if you suspect / have been hacked.
   
10. Appearance or reality: Pay attention to the domain name. This is always highlighted in white in Firefox. Do you recognise it?
11. Hardware risk: Unplug all external hard drives and USB devices. Do you recognise them? Is a keylogger included?
12. Normal user: Don’t work with an admin account all day. Create a normal user for your daily work.
13. Weekly obligation: Only a weekly or daily backup will help against zero-day malware and ransomware.
14. VBS and macros: Never execute macros or scripts in Office documents.

Detection and clean-up

Antivirus programs recognise malware with “signatures” that resemble a unique fingerprint. If the antivirus finds a known malicious fingerprint, the software prevents execution, deletes the file or moves it to quarantine.

Manual cleaning is possible. This form of clean-up is only suitable for people who like to read long technical descriptions and carry them out meticulously.

The criminals behind the malware want to make the removal process as difficult as possible so that the damage is as great as possible.

In the worst case, a reinstallation is necessary. You will need to reformat the hard drive, reinstall Windows, install all programs and import a data backup.