A worm is a malicious program (malware) that propagates itself and duplicates itself. A well- known example is the email worm that circulated in the year 2000, with the subject line, ILOVEYOU, and deleted numerous files.
What does the term “worm” mean in detail?
The terms virus and worm are often used interchangeably. However, these malicious programs differ in some aspects. For example, a computer virus needs a "host file" while a worm can operate autonomously. For users, however, this distinction is secondary. Worms are distributed via networks (eg via email), USB sticks, external hard disks and other removable media. Also, small USB devices such as a USB cup warmer may contain worms. There are many different types of worms, even mobile phone worms that transmit via Bluetooth. Worms can use different tactics to spread. For example, the ILOVEYOU worm acted like a Trojan horse: the appendix with the malicious code was disguised as a love letter.
Where would I encounter worms in my daily work?
Since worms use diverse distribution channels, this topic can be encountered in many locations.
Example 1: After a customer conversation, you want to transfer a document to your customer’s USB stick. You connect the USB stick to your computer and check it first with your antivirus program. It discovers and removes a worm; by being prudent you have prevented a cyber attack.
Example 2: You receive an email from a customer. A document is attached. The email looks strange; you check the sender’s address r, but it’s correct. Instead of opening the attachment, you check it with your virus program. It discovers a worm and you've just spared your company a cyber attack.
How can I protect myself from worms?
Many measures that increase your company's cyber security provide protection against worms. Among other things:
- Analytical handling of emails, links and removable media such as USB sticks and external hard disks.
- Keep operating systems and all programs up-to-date with updates.
- Antivirus software, which is always up-to-date and frequently used.
- A firewall, because it can stop the spread of a worm.