Malware, also known as malicious code and malicious software, refers to a program that is inserted into a system, usually covertly, with the intent of compromising the confidentiality, integrity, or availability of the victim’s data, applications, or operating system or otherwise annoying or disrupting the victim. Malware has become the most significant external threat to most systems, causing widespread damage and disruption, and necessitating extensive recovery efforts within most organizations.
There are five types of malware:
- Ransomware – Ransomware is a subcategory of malware that typically will block access to computers or data until a payment is made.
- Trojan – A Trojan is a self-contained, non-replicating program that, while appearing harmless, actually has a hidden malicious purpose. Trojans either replace existing files with malicious versions or add new malicious files to hosts.
- Spyware – Spyware is a type of malware used to covertly observe a user’s activity and gather information about a user without their knowledge or consent.
- Virus – A virus self-replicates by inserting copies of itself into host programs, data files or propagating through network file sharing. Viruses are often triggered through user interaction, such as opening a file or running a program.
- Worm – A worm is a self-replicating, self-contained program that usually executes itself without user intervention.
Signs to Look Out For:
- Slow performance
- Unexpected computer crashes
- Pop-up ads (even when no browser is open)
- Excessive hard drive activity
- New browser homepage or toolbars
- Unexpected Antivirus disabling
- Lost functionality
Ways To Avoid An Attack:
- Do not open suspicious emails or email attachments, click on hyperlinks, etc. from unknown or known senders, or visit websites that are likely to contain malicious content
- Do not click on suspicious web browser popup windows
- Do not open files with file extensions that are likely to be associated with malware (e.g., .bat, .com, .exe, .pif, .vbs)
- Do not disable malware security control mechanisms (e.g., antivirus software, content filtering software, reputation software, personal firewall) and ensure that they are continuously updated
- Do not use administrator-level accounts for regular host operation
- Do not download or execute applications from untrusted sources