Top 5 Internet Viruses to Protect Against – Worst Computer Viruses Today

By Conner Sinclair | Online Security

There is nothing worse than getting your computer or computing device mucked up with a nasty virus. While most people are familiar with common terms like “trojans” and “worms”, specific threats vary as quickly as the software is released to combat the old identified threats.

It is estimated that cyber crime causes anywhere from 300-800 billion dollars in damage annually. While not necessarily the worst viruses of all time (see here for a list), these 5 viruses are more recent threats that internet users should be aware of today.

1) TDSS (otherwise known as Alureon)

TDSS is one of the more common viruses currently in existence. It is essentially a Trojan with a bootkit aimed at stealing sensitive data such as credit cards, passwords, and usernames. The target is PCs running Windows and the delivery method is usually via user installation.

It is common to see Alureon bundled under the guise of “security software” with Security Essentials 2010. Once activated, the bootkit moves to establish its own rootkit, changing the master boot record and infecting a variety of system drivers.

The most common manifestation is the inability to access Windows Task Manager and the desktop, as well as blocking access to many anti-virus products and Windows Update.

2) CryptoLocker

CryptoLocker was discovered around September 2013 as a Trojan. In particular, this is a “ransomware” specifically targeting PCs running Windows. While their were other sources, the main avenue of attack was via email.

Harmless looking attachments were the culprit in this situation, leading to malware encryption (RSA public-key cryptography). Once activated, victims are presented with a barrage of messages offer to decrypt their data for payment (usually Bitcoin or another form of voucher). Accompanying the demand is a deadline (hence the word “randsomware”). If not paid for by the deadline, the price increases.

3) Win32 (fakesvdef)

Win32 uses the Trojan Horse structure to target Windows operating systems. The initial attacks were documented towards the end of 2010. Originally, the Trojan affected users by way of an application named “HDD Defragmenter”, offering a false service to scan and “defrag” your computer (similar to Windows Disk Degragmenter which comes standard on most PCs).

The scan would display false issues with your computer once the scan was complete, requesting payment to “resolve” the issue.

4) Zeus

Zeus is a botnet toolkit designed to create malware and infect your computer. The goal is usually to steal identities, bank information, and other data. What makes Zeus particularly difficult is that it replicates other botnets to penetrate other data sources on your system.

First discovered in 2007, the virus became ubiquitous by Spring 2009. The primary method of attaching is via benign appearing downloads and email “phishing” schemes.

5) Zeroaccess (also goes by Sirefef and max++)

Zeroaccess is a seemingly benign rootkit that is aimed at simulating clicks on web advertisements and Bitcoin mining on host machines. While it remains hidden from view, it essentially uses your PC as a mechanism to commit fraud. It forms what is called a “botnet” that executes the click fraud.

This malware slips under the radar precisely because it is only using the Windows device as a vehicle (as opposed to ransomware which is targeted at the user specifically).

So, what is the best way to protect against these new and emerging threats? First and foremost, keeping your system up to date. Is Windows going to always be slightly late with their updates? Probably. Should you download your Windows Updates? Absolutely.

Secondly, invest in a quality antivirus application. For example, one of our top recommendations is ESET Nod32 Antivirus. You can read my full review of the ESET software here.

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About the Author

Conner is a self-professed tech nerd, obsessed with digital security and privacy. He loves debugging "lost causes" and thwarting hackers. When not in his depressing cubicle in Corporate America, he's blogging here.