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Computer virus (malware)
Updated 2023/10/6
Computer virus (malware) is malicious software that is intentionally created by an unscrupulous person to cause harm to a computer or its users.
Types of malware
There are many different types of malware, and they are evolving every year. Here are some of the most common ones
| Viruses | Infects and spreads by rewriting legitimate programs or parasitizing legitimate programs. |
| Worms | Unlike viruses, worms exists as a program standalone. It is a type of malware that uses the network to spread infection like a virus. |
| Trojan horses | Disguises itself as legitimate software and hides in plain sight to do evil. It receives commands from the outside (backdoor) and manipulates the infected computer. |
| Spywares | Steals personal information, data, etc. from infected computers. Secondary incident can occur if information such as keyboard input and passwords stored on the computer are stolen. |
| ransomware |
Encrypts the files on an infected computer or shared folder and demands a ransom. Recently, some threats have been made by collecting files before they are encrypted. |
| Scareware |
It threats user. Recently, there have been cases where a warning message such as "Your computer is infected with a virus" is displayed and the user is forced to install unauthorized software, or a phone number is displayed and the user is scammed if they call the number. |
| Adware |
Forcibly displays advertisements that are not intended by the user. |
Malware infection chain
There are various ways to get infected with malware. Here are some of the most common ones.
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Sometimes, attachments may be malware. Opening the attachment may start downloading the malware. A link in the body of an email may be download link of malware. Office documents (such as Word and Excel) with macros often download malware via macros (called "macro viruses"). |
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| Browse the website |
Accessing a site with embedded malicious code may result in the download of malware or the execution of malicious programs in your browser. |
| Downloads |
Downloading malicious software can lead to the installation of malware. Legitimate software can be tampered with and infected with malware. Automatic software updates can also lead to malware infection. (Supply chain attack) |
| Vulnerabilities |
Some exploit software glitches in operating systems or applications to take away administrative privileges or download malware. A worm can spread through the network by exploiting software vulnerabilities. Be sure to update your software frequently. |
| USB memory stick | Although we don't see it very often these days, some viruses can be transmitted via external storage devices such as USB memory sticks, etc. If the auto-execution of external storage devices is enabled in the operating system, the computer can be infected by just connecting it. |
Protecting yourself from computer viruses
- Install anti-virus software on all laboratory and personal computers and update anti-virus software regularly.
- Back up important data.
- Stop running the executable file attached to the email. You also need to be careful about emails from acquaintances.
- Avoid downloading files from the home page.
- Do not download or run pirated software or games from the homepage.
- Check for viruses before using USB memory.
- If your laboratory or personal computer is a Windows machine, run Windows Update regularly. (Security related bug fixes)
Let's check the virus related information page.
If you get infected with a computer virus
If your computer is connected to the network, disconnect it from the network. Do not turn off the computer, but contact the Informational Innovation Section.
Computer virus link
・Center for Science Information: Use of anti-virus software on campus 
・Trend Micro Virus Buster online scan 
・IPA (Information Processing Promotion Business Association) Security Center