Spotting a malware infection can prove difficult nowadays. In the past, popups and fake antivirus programs made it easy to detect an infection. Those types of malware still exist, but malware now can assume a much more sinister (and sneakier) purpose. Their goal is to exist undetected on your PC for as long as possible, so they are programmed to be unobtrusive and undetectable. Here are some things you might not even know your computer is doing behind your back:
The first thing any piece of malware wants to do is procreate. Malware can stealthily exploit local networks to infect other unprotected PCs on the network. Particularly virulent malware, like the Nimda worm in the early 2000s, can replicate itself so quickly that it can bring down entire business networks.
Some malware attacks web browsers and DNS entries to redirect browsers from safe websites to malicious sites. Some malware simply redirects 404 error pages or default search engines to other sites with advertising. Others can be more malicious; a recent malware infection completely took over as the DNS server for millions of PCs until it was finally shut down.
These little programs run silently in the background of your PC, recording every keystroke you make and then transmitting them to the hacker or hackers that wrote them. That means the passwords to all of your email accounts, bank accounts, and anything else that you typed into your PC are compromised. Keyloggers are a favorite tool of identity thieves and hackers alike.
While some malware operators’ goal is identity theft, others are out to send as much spam as possible. That requires gaining control over as many computers as they can to relay those spam messages. Many malware programs give spammers silent control over your computer, using it to send spam. These networks of compromised computers are known as “botnets”.
Denial of Service Attacks
Like spammers, hackers also want control over your PC for use in botnets. Activist hackers and digital vandals use botnets to send streams of data from every computer simultaneously to overload target websites in what is known as a denial of service attack.
Keeping your antivirus current is not enough, though many users fail to do even that. Malware exploits security holes in Windows as well as web technologies such as Java and Flash. It is crucial to keep your programs up to date with the latest security patches to protect from these exploits.