How can you avoid downloading malicious code?

Kristina Oleinichenko Kristina Oleinichenko / September 25, 2022 / Data Privacy

Most cyber threats, whether designed to steal data or extract money from a user, have malicious code at their core. Once this malicious code finds its way onto a device, it can be devastating: particularly if it first infects one machine before spreading through an organisation’s network.  

Worse, the more sophisticated the malicious code, the harder it is to remove. So, it’s wise to be proactive about avoiding downloading malicious code in the first place. It’s far better to ask, “how can you avoid downloading malicious code?” than to be forced to ask, “how can I get rid of this malicious code?!”. 

With that in mind, this post explores 7 top tactics for protecting yourself from malicious code. 

How can you avoid downloading malicious code? – 7 effective tips

Install a robust antivirus solution 

Antivirus software is often the first line of defence for protecting yourself from malicious code. Antivirus software scans your device for malicious code in the form of malware, adware, spyware, viruses, etc., before removing them. Antivirus software also lets you know if you’re trying to connect to an unsecured site, which is more likely to contain malicious code. Additionally, many antivirus applications include a firewall, which analyses incoming web traffic for extra security.  

Consistently apply patches and updates  

Unpatched software is responsible for 1/3 of all security breaches, so applying all available patches and updates is crucial.  Although you should get into the habit of doing this for any application you use at least semi-regularly, it’s most especially to consistently update your operating system (OS) and antivirus software. Updating your OS regularly is vital because hackers frequently exploit their vulnerabilities. Similarly, the developers of antivirus software release patches and updates to account for new and emerging cyber threats, so consistently applying them gives you the most secure tools to avoid the question how can you avoid downloading malicious code on your device.     

Avoid unsecured websites 

A secure website is recognisable through a small padlock next to its URL or the “https://” prefix within its URL. This signifies that the site has a Secure Socket Layer (SSL) certificate, which creates an encrypted connection. Subsequently, an SSL certificate makes it incredibly difficult for bad actors to infect a site with malicious code. 

Conversely, unsecured sites don’t have an SSL certificate and have an “http://” prefix in their URL. Such websites are less secure, so hackers can infect them with malware, ransomware, Trojan horses and other types of malicious code. Luckily, as mentioned above, antivirus software alerts you when you’re about to access an unsecured site, making it less likely you’ll stumble onto one by accident. 

Use DNS filtering 

A potent way to avoid unsecured sites is through DNS filtering. By blocking unsecured sites at a DNS level, you’ll avoid downloading malicious code by preventing certain domains from even loading in the first place adn avoid DNS hijacking.

As all requests to access a website go through a DNS resolver, it can be configured to filter out queries for domains on a blocklist. A URL might end up on a blocklist because they’re unsecured or contained malicious code in the past. Alternatively, instead of a blocklist, DNS filtering can use an allowlist that only resolves a determined set of domains while preventing all others from loading.   

Don’t download free software 

Downloading free software can sometimes lead to downloading malicious code for two reasons. Firstly, bad actors may insert malicious code into the website from which you download the software. By luring visitors to their site with the promise of a great, highly-functional application – at no cost – they can infect their machine with malicious code. 

Secondly, cybercriminals can infect your device with malicious code through the software itself. Very simply, the software masquerades as secure and legitimate – while really being malware, adware, ransomware, or spyware. Once the malicious code is on your device, it’s far easier for bad actors to install more and get a firmer grip on your machine.  

However, with all that in mind, not all free software is dangerous. Chances are you’ve downloaded a free application before and didn’t fall victim to a cyber threat.  So, how can you avoid downloading malicious code from free software? First and foremost, make sure it comes from a reputable company: if you’ve heard of them, that’s a good sign. If you haven’t heard of the developer, do a quick search for reviews for the application you’re looking to download. Reddit is usually a place for objective reviews, and you’ll quickly find out if there have been issues with malicious code. 

Be extra vigilant when clicking links 

Phishing is the most common type of cyber attack and centres around tricking people into clicking on malicious links on websites, social media posts and, especially, emails. When an unsuspecting victim clicks on a phishing link, it often results in the installation of malicious code in the form of malware or ransomware.  

Because phishing links frequently look like they’re from authoritative domains, like banks and payment processors, you can avoid them by looking at the domain carefully before clicking it. The cybercriminals behind phishing attacks usually slyly replace one character with another that looks just like it – such as an ‘O’ with ‘0’ – which is sometimes hard to notice at a glance. Fortunately, many phishing attempts are easily foiled if you pause, consider the message’s origin, and, crucially, if it seems too good to be true. So, if you want to know how can you avoid downloading malicious code – avoid phishing emails.  

Use advanced email filters 

While on the subjects of emails, you can avoid lots of phishing emails altogether with advanced spam filters (ASF). ASFs protect you from malicious code by conducting deep scans on emails, including attachments. ASFs add a layer of security by highlighting messages as potentially malicious based on specific message properties commonly found in spam.  

Want to know more about how can you avoid downloading malicious code? Contact RiskXchange for a free attack surface risk score today.