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What is a Virus?
8/9/2023 - Brian O'Neill

Computer Virus

The word “Virus” is often used as a catch-all term to describe any malware that infects a computer. The real definition is a bit more specific than that, however, so it’s important to make that distinction clear.

Computer viruses are malicious programs designed to latch onto files and replicate themselves throughout a system. Unlike other similar & equally prevalent forms of malware which can spread completely autonomously (i.e., worms), viruses require some form of interaction to initiate the injection of a malicious payload before they can spread from file to file and/or from system to system. The term “virus” is a direct reference to biological viruses which spread from person to person through regular human contact.

How do Computer Viruses Spread?

Viruses are most often perpetuated via widespread dissemination of infected files or compromised URLs through popular communication mediums like email. Common Office document formats like Excel, MS Word, and others have been utilized for this purpose for several decades. For example, as far back as 1999, an infamous virus (named the “Melissa” virus) afflicted more than 250,000 computers, hijacking email applications on the devices it compromised to rapidly share Office documents containing infected macros with other unsuspecting users.

Today, the increasing popularity of applications which allow direct file upload processes means these same infected documents and URLs can now enter professional networks through insecure upload portals.

Even before the internet took off in the early 1990’s, cybercriminals transmitted primitive computer viruses over floppy disks. While floppy disks themselves are now a relic in the history of computer hardware, their modern-day equivalents (hard drives and USB storage devices) are still utilized to accomplish the same outcome – albeit less frequently than methods involving internet communication.

Cybercriminals can also disguise viruses as seemingly legitimate software/application downloads. In such cases, the virus can be more accurately described as a “Trojan Horse”, or “Trojan” for short. Once a user initiates a download, the virus can spread rapidly through their file system and exploit an exponential number of sensitive file locations, one after the other, until the entire system is compromised.

What is the Impact of a Virus Attack?

Virus attacks often lead to disastrous outcomes for a target device and/or its network of adjacent devices. Viruses can be designed to rapidly exfiltrate, delete or hold sensitive data hostage (i.e., ransomware), interfere with a device’s regular functionality, compromise a device and utilize it in subsequent attacks (i.e., botnet attacks) on external devices, and much more. The scope of the impact a virus can have depends largely on the specific type of virus which is used and the security architecture of the affected device/network of devices.

How can Virus Threats be Mitigated?

Because viruses most often require users to open infected files, click on & visit malicious URLs or physically insert compromised hardware into their device, extreme caution around potentially untrustworthy content remains one of the strongest best defenses against virus attacks. Emails containing malicious attachments and URLs are often identifiable by small errors or inconsistencies in the email domain or in the message body itself, and infected file uploads often have suspiciously complex or generic titles.

Detecting Viruses with the Cloudmersive Virus Scan API

Deploying the Cloudmersive Virus Scan API (Basic or Advanced versions) will help protect your system against a continuously updated list of 17+ million virus and malware signatures. This API accepts URLs and a wide range of file types (including all Office formats, HTML, PDF, .ZIP, over 100 image formats, and more), and specific iterations of this API can be deployed to scan AWS S3, SharePoint Site Drive, Azure Blob, and Google Cloud files in-storage.

For more information on Cloudmersive Virus Scan APIs, please do not hesitate to reach out to a member of our sales team.

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