Computers being connected to the internet and or other networks are subject to being infected with unwanted software. Undesirable software can be just annoying, or it can also render difficult to use by forcing users to view advertising or open website against their control. Some types of these infections can try to mislead by offering to “cure” the computer in exchange for payment. Or worse yet, lock up the data and communications on the computer demanding payment be sent to release them.
Viruses are meant to spread between computers with the goal of either disrupting systems, causing operational issues, damaging data and software, as well as to steal sensitive information such as banking or other confidential data.
Computer viruses are a special type of software that is programmed to attach itself to other programs and then execute when they are used. It can reach a computer via a USB device, external drive or by connecting to the network including the internet. Another way a virus can be spread is through something called a phishing email. These emails include what looks like either an important document or links to something that does not look harmful. These attachments that are found in emails may contain viruses so it is best to not open them until you know that they are safe.
Once a virus is in the network it is designed to spread to other computers and systems. Viruses typically attach themselves to executable files (programs or Apps), then when that file is opened the virus is spread. Computer viruses can be difficult to detect even with the most sophisticated protection software.
Signs of your computer being attacked by a virus are varied and more than one of these signs may appear:
- The computer slows down simple functions or surfing the internet may seem delayed or not as quick as previously
- Popup windows that appear on the computer screen without the user selecting anything including advertisements or a window that cannot be dismissed prompting payment to solve the current problem
- Programs can also either run by themselves or refuse to function
Sophisticated malicious software will force software tools that remove them not to function. Often as viruses are not debugged and carefully constructed as commercial software, the computer will suddenly refuse to function or restart. If your computer starts sending large amounts of email, or your contacts tell you they are receiving emails from you that you did not send, this can also be a sign of infection.
Ransomware is a special type of malicious software. It is not just an annoyance or easily removed like other problems. The term ransomware refers to the fact that your files or even your computer are held for a ransom to be unlocked and useful again. Not only that sometimes even when the ransom is paid, the perpetrators do not unlock the computer. Ransomware can affect not just one computer, but an entire network of computers. The best practice for protecting against is to have a system of continuous backups, that can be used to restore the computer(s) quickly. This way, the computer can be restored to a point in time before it was infiltrated. Ransomware is becoming more common, especially in organizations that cannot function without their computers and data.
To prevent viruses from infecting and spreading on a computer or network, a specific software can be used to analyze and halt infection. As well a firewall between the computers and outside internet traffic can stop malicious items before they can even enter the network. A good education for the end users of computers in a company can also help prevent problems. Teach them not to read unknown documents or links to files that did not originate from within the organization, or ones that do not appear to be the expected email types. Pirated or stolen software can often be a source of infection as it gives outsiders a chance to put an infected program on your computer with your permission.
As mentioned before a robust continuous backup system is important so that systems can be reinstated and function again quickly in the case of a cyberattack. Alternately, if all data files are kept in a cloud system, the operating system and applications can be reinstalled from scratch, eradicating any infection. This can be a time-consuming process but will ensure that most infections are removed.